Blogs of Professor Pranab Kumar Bhattacharyya MD(cal) Pathology; : The First Generation of Stars formation at Red shi...: http://www.sciencenews.org/view/generic/id/48016/description/ Authors _; * Mr . Rupak Bhattacharya -Bsc(cal) Msc(JU) of Residence 7/51 ...
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Sunday, 31 March 2013
Blogs of Professor Pranab Kumar Bhattacharyya MD(cal) Pathology; : The First Generation of Stars formation at Red shi...
Blogs of Professor Pranab Kumar Bhattacharyya MD(cal) Pathology; : The First Generation of Stars formation at Red shi...: http://www.sciencenews.org/view/generic/id/48016/description/ Authors _; * Mr . Rupak Bhattacharya -Bsc(cal) Msc(JU) of Residence 7/51 ...
The First Generation of Stars formation at Red shift Z-0 and when did they lit up from the dark Matter
http://www.sciencenews.org/view/generic/id/48016/description/
Authors_;
* Mr. Rupak Bhattacharya-Bsc(cal)Msc(JU) of Residence 7/51 purbapalli,Po-sodepur, Dist 24 parganas(north),Kol-110,West Bengal, India**ProfessorPranab kumar BhattacharyaMD(cal) FIC Path(India); Professor and Head of Department of Pathology [course coordinator of DCP course of West Bengal University of Health sciences(WBUHS); member secretary of Board of Studies for DCP course and member of Board of Studies for undergraduate, Post graduate & Doctoral courses in Pathology Discipline of WBUHS],School of Tropical Medicine, 108 CR Avenue ,Kolkata-73, West Bengal , India,** Miss Upasana Bhattacharya- Student, Mahamayatala, Garia, kol-86, Only daughter of Prof.PK Bhattacharya ***Mr.Ritwik Bhattacharya B.com(cal) of Residence 7/51 Purbapalli, Po-Sodepur, Dist 24 parganas(north) , Kolkata-110,WestBengal, India **** Mrs. Dalia Mukherjee BA(hons) Cal, Swamiji Road, South Habra, 24 Parganas(north) West Bengal, India**** Miss Oaindrila Mukherjee- BA(hons)cal Student, ****Miss Ayshi Mukherjee –Student of residence Swamiji Road, South Habra, 24 Parganas(north), West Bengal, India ***Miss Rupsa Bhattacharya and ***Mr Somyak Bhattacharya BHM(IGNOU) Msc student(PUSHA) of 7/51 Purbapalli PO-Sodepur Dist 24 Parganas(north) Kolkata-110 West Bengal, India and Mrs Runa Mitra of BK Mitra Social Worker Barrackpore
* Mr. Rupak Bhattacharya-Bsc(cal)Msc(JU) of Residence 7/51 purbapalli,Po-sodepur, Dist 24 parganas(north),Kol-110,West Bengal, India**ProfessorPranab kumar BhattacharyaMD(cal) FIC Path(India); Professor and Head of Department of Pathology [course coordinator of DCP course of West Bengal University of Health sciences(WBUHS); member secretary of Board of Studies for DCP course and member of Board of Studies for undergraduate, Post graduate & Doctoral courses in Pathology Discipline of WBUHS],School of Tropical Medicine, 108 CR Avenue ,Kolkata-73, West Bengal , India,** Miss Upasana Bhattacharya- Student, Mahamayatala, Garia, kol-86, Only daughter of Prof.PK Bhattacharya ***Mr.Ritwik Bhattacharya B.com(cal) of Residence 7/51 Purbapalli, Po-Sodepur, Dist 24 parganas(north) , Kolkata-110,WestBengal, India **** Mrs. Dalia Mukherjee BA(hons) Cal, Swamiji Road, South Habra, 24 Parganas(north) West Bengal, India**** Miss Oaindrila Mukherjee- BA(hons)cal Student, ****Miss Ayshi Mukherjee –Student of residence Swamiji Road, South Habra, 24 Parganas(north), West Bengal, India ***Miss Rupsa Bhattacharya and ***Mr Somyak Bhattacharya BHM(IGNOU) Msc student(PUSHA) of 7/51 Purbapalli PO-Sodepur Dist 24 Parganas(north) Kolkata-110 West Bengal, India and Mrs Runa Mitra of BK Mitra Social Worker Barrackpore
Age of Universe & Hubble constant=The universe started at 20x1010
(20,0000 millions years ) ago but there are still uncertainty about the ages of
the universe according these authors. Determination of Hydrogen molecule
suggest that H~50Km/s-1MPC-10H-1=20x109
years, while
age old galactic clusters NGC is 10x109 years and the age of
elements obtained from the active isotopes were ~10x109
years. The Freidman and Le -maitre models of universe tell us that the
universe however has a finite age and it must be either expanding or contracting.
The observation that galaxies are in red shift having special features of
shifted to redder wave length in an apparent Doppler recession, strongly
support the expanding universe model. Confidence in the Friedman- le-maitre
model was strengthening further when Edwin Hubble discovered the near
relation between red shift and distances in galaxies in 1929. Hubble
discovered a cosmological
constant and this constant is proportionally is known widely as Hubble constant.
The H(0) is usually expressed in terms of
Kilometers per second per mega Per sec ie 50 Km/s/MPC Hubble constant.
The Hubble parameter is defined as H(t)=1/R(t)xdR(t)/dt, where R(t) is the
scale factor of the universe. Hubble constant is the current value of that
parameter and defined as H0=H(now)=
velocity/distance and is estimated by measuring the velocity and distance of
extra galactic objects. Hubble constant is perhaps the most important parameter in
cosmology because it not only provide us the physical scale of the universe
which affects the observed absolute size, dynamical mass and luminosity of
extra galactic objects but it also provide us estimated age of the universe.
The Hubble constant has the units of inverse time. An estimate of the age of
the universe is the Hubble time 1/H0. This is the approximate age of
a nearly empty universe one, where expansion had not significantly been solved
by its mass energy content. A new Model called Ω=1 model, whereΩ is ratio of the
universe mass energy density to the critical value required for binding. In the Friedman- Le maitre models the expansion rate of the
universe approaches 0 as time approaches and the current age of the universe will be then(2/3) H0-1 is then
Age=1/H0[(1-2q0)-1-q0(1-2q0)-3/2
cos h-1(1/q0-1)] where the de-acceleration parameter q0
is (1/2)Ω the ratio of the universe mean mass density to the closer density[
Bhattacharya Rupak and Bhattacharya Pranab Kumar-unpublished data & equation
Published in this blog Do not try to do plagiarism]
The age of the universe
when H0 is of 50KmS-1MPC-1 gives an age of near 20
billions years
while an H0 of 10050KmS-1MPC-1 in
an empty universe roughly correspond to an age of 10 billion years. But
the Cepheid variables are the bright stars where brightness varies
periodically on time scale between one and hundred days. The period of Cepheid is
very tightly correlated with its brightness. So they are the excellent indicators of
distances of expanding universe and also the age of the universe. Cephids are most
distant galaxies of the observable universe and are figured
prominently in the extragalactic distance scale. Cepheid first gave us the idea
that other galaxies lay outside our Milky way galaxy. Virgo cephid or
Virgo galaxy clusters are so far
farthest, twice as far as the most distant previously measured cephids. They
are now measured by Hubble Space Telescope(HST). New example of Virgo cephid H0=87±
7 Kms-1MPC-1. The galaxy there NGC 4571 is in the core of
Virgo clusters galaxy. Again Taking H0 as H0=87± 7 Kms-1MPC-1
as short value ( H0=80-100 Kms-1MPC-1)
[Picture
of Virgo clusters of galaxy taken by
Rupak Bhattacharya]
and long value H0=50 Kms-1MPC-1)
will after the age of the universe for 20 billions years to 11.2±0.9 billions
years and 7.3±billions years for Ω=0 model and Ω=1 model respectively. The absence of
accelerating force for the age of universe is less then 1/H0 and in standard Big Bang Model is 2/3x1/H0 0r 7x109 years.
In contrast some stars are thought to be 8x109 years old, .So here starts the crisis regarding the age of the universe
what these authors feels. In Freidman Universe model, Freidman et al calculated Ho=80+17 Kms-1MPC-1
implying the age of the universe 9x109 years. In that case, identifying 20 cephid variables in m 100
a beautiful spiral galaxy in Virgo. However if we are ready to accept the
theory that age of the universe is estimated from the cosmological model based
on Hubble constant, as per this model the age
of universe will be 13.7±0.2GYR ie 13.7 billions years old.
Though a big bang like event happened in the
early universe, universe
spent a period of time in the early phase (1s Planck’s time) in a super cooled
stage[About
400,000 years after the Big Bang, that the cosmos had cooled sufficiently for
protons and electrons to recombine into atoms]. In the super cooled stage its
density (3K) was then dominated by large positive constant vacuum energy and
false vacuum. The
super cooled stage was then followed by appearance of multiple bubbles
inflation. The temperature variation occurred in 3K cosmological
background imprinted some 10~35
second in pre- inflationary stage and grand unified theory [GUT] happened there
with generation of trillions and trillions degrees of temperature. As per old
inflationary theory of Big Bang, there appeared multiple bubbles of
true vacuum and inflation blowed up a small casually connected region of the
universe that was some thing much like the observable universe of today.
This actually preceded large scale cosmological homogeneity & were reduced
to an exponentially small number the present density of any magnetic monopoles,
that according to many of particle physicists GUT & would have been
produced in the pre-inflationary phase. In the old inflationary theory the
universe must be homogeneous in all its direction and was no doubt
isotropic. In old inflation theory, the super cooled stage was married by
appearance of bubbles of the true vacuum, the broken symmetry of ground state. The model of old inflation
theory however was later on abandoned, because the exponential
expansion of any super cooled state always present the bubbles from merging and
complicate the phase transition. More over in true sense,
universe is not totally homogenous but in small scale non homogenous too.
It is very much a well known fact that
universe contain a critical density of matter (3K) and infinite space-time. The
matters are mostly baryonic and Mixed Dark matter [MDM]. Through COBE
satellite studies, we know that the early universe was consisted of
mixture of Cold Dark matter and hot dark Matter, which is known altogether as
Mixed Dark Matter [MDM]. Most Red shift survey had been either shallow
(Z=<0.03), three dimensional survey of few thousands of galaxies covering a
large angle or somewhat deeper (Z>0.05). So argument still persist about the mechanism by which
galaxies/first generation stars were formed in the early universe?. The essence of the problem
is so high level physics that while galaxies were on average, uniformly
distributed through out the volume of the universe, as it should be in the
Inflationary “ Big Bang” model, the observed distribution of both optically
visible and radio galaxies on the sky were not uniform. But very much patchy( Authors Prof Pranab
Kumar Bhattacharya’s Concept only). Does this clumsiness’ represent
that the distribution of matter at some primeval stage in the evolution of the
universe or there had been some kind of gravitational process?. Ostriker and
cowie in the journal Astrophysics (Vol 243; P127; 1981) had suggested that
the present distribution of galaxies are in the relic of a dynamic process, in
which an outward propagating shock wave created an earlier generation of
galaxies. Created galaxies at some places were of high density on shock front.
But the problem of their theory to present authors are that the
empirical rule, which says that the chance finding of a second galaxy
within same value unit at a distance of “S” is proportional to an inverse power
of ”S”, which simply means that there is a greater chance that galaxies will be
close together than it is far apart. Secondly the distribution of galaxies in
the universe may have a fractal three-dimensional structure. The most
spectacular of large voids in three dimensions of galaxies is the BOTES VOID.
-A region at least 50 MPS in diameter that contain no luminous galaxies. Why? A
survey of large-scale galaxies distributions reveals that the “ Large Voids “
were not the exception, but the rule. The survey was the systemic collection of
Red Shifts of all galaxies of apparent magnitude brightness than 15.5 in a
region measuring 6 degrees by 12 degrees on the sky. These Red Shifts via
“Hubble laws” provides us a three dimensional map of galaxy distribution in a
limited volume of the universe. Inspection of the map of the galaxy revealed a
striking result- large apparently empty, quase spherical “Voids” dominate space
& time and galaxies are crammed into the thin shits and ridges in between
hole. (Joseph Sick- Nature-Vol.320; P12; 1986) Joseph Sick discussed in
his article published in Nature (Vol 320; p12; 1986) that galaxies were
distributed in a thin slice of universe to 150 MPC. The red shift measurement
of galaxies however reveals a foamy and clustered distribution of galaxies in
the universe. Most of them lying on a sheet, surrounding large, almost empty
holes up to 50 MPC According to Ostriker and Cowie, an explosion initiated by
many supernovas in a newly formed galaxy drive a blast wave, which propagated
outward and swept up a spherical shell of ambient gas. A hole was thus
evacuated and the unstable compressed shell fragmented to form more galaxies.
These in turn developed blast waves and a series of bubbles developed that
filled most of the spaces with galaxies (Jeremiath Ostriker & Lennoy Cowie-
Astrophysics journal letter Vol 243; P127; 1981) and published independently by
Satron Ikeuchi-Astronomical Society of Japan Vol, 33; P211; 1981) But the problem of this
hypothesis before present authors are * 1) possibility of the
mechanism itself- Supernova exploded and cleared out holes that are
tens or in rare cases hundreds of parsec cross? And* 2) did this
phenomenon really worked out on scale of MPC? *3) Billions of supernovae were presumed to be exploded
coherently over the crossing time of galaxy of about 108 years to
yield a vast explosion 4) Next is the missing
ingredients which is Gravity. Density fluctuations were present at
the beginning of the time in the earliest instants of the” Big Bang gospel” and
the gravity amplified the fluctuation into large-scale structure of the
universe. Most cosmologists& theoretical
physicists believe today that galaxies were originated in this manner rather
then by explosive amplification of primordial seeds which themselves must be
attributed into initial condition.
A “giant hole” in
the universe had been a discovered by astronomers from Minnesota in 2009 January. Investigating an
area of the sky known as the WMAP Cold Spot, Lawrence Rudnick and colleagues
found a void empty of stars, gas and even dark matter. As AP’s widely
circulating report notes, the hole is big: an “expanse of nearly 6 billion
trillion miles of emptiness” Astronomers have long known that there are big
voids in the universe, and think they can explain them with their theories as
to how large scale structures first formed.[ Daniel Cressey”
Plenty of nothing - August 24, 2007The Great Beyond Nature.Com
http://blogs.nature.com/cgi-bin/mt/mt-tb.cgi/3329].our Galaxy, the Milky Way, contains also disks
of ‘dark matter. Dark’ matter is always invisible but its
presence can be inferred through its gravitational influence on its
surroundings. Dark matter particles is neutral it does not couple directly to
the electromagnetic field, and hence annihilations straight into two
monochromatic photons (or a photon and a Z boson) are typically strongly
suppressed. γ-rays can be a
significant by-product of dark matter annihilations, since they can arise
either from the decay of neutral pions produced in the hadronization of the
annihilation products, or through internal bremsstrahlung associated into charged
particles, with annihilations into charged particles,
interactions of energetic leptons. In the Lattanzi & Silk models the annihilation
results in two neutral Z bosons Or a pair
of W+ and W. bosons, and the dominant source of γ-rays is neutral
pion decay. Form_ = 4.5 TeV, every annihilation results in 26
photons with energies between 3 and 300GeV.
Physicists
today believe that dark matter makes up 22% of the mass of the Universe
(compared with the 4% of normal matter and 74% comprising the mysterious ‘dark
energy’). But, despite its pervasive influence, even today no-one is sure what
dark matter consists of. It was thought that dark matter forms in roughly
spherical lumps called ‘halos’, one of which envelopes the Milky Way and other
spiral galaxies. Stars and gas are thought to have settled into disks very
early on in the life of the Universe and this affected how smaller dark matter
halos formed. Such a theory suggest that
most lumps of dark matter in our locality actually merged to form a halo around
the Milky Way. But the largest lumps were preferentially dragged towards the
galactic disk and were then torn apart, creating a disk of dark matter within
the Galaxy. The presence of unseen haloes of Dark matter had long been inferred
from high rotation speed of Gas and stars in outer part of spiral galaxies. The
volume of density of these dark matter decreases less quickly from the galactic
center than does heat luminous mass such as that in stars meaning that dark
matter dominates the mass from the center of galaxies. A spiral galaxy is
composed of thin disk of young stars called( population I stars) whose local
surface brightness falls exponentially with cylindrical distances from galactic
center and with height above galactic plane.
The
concept of biasing the formation of large scale structure of universe
was first introduced by Nick Kaisar in journal of Astrophysics (Peacock
.JA &Heavens A.F- Monday Nottingham. Royal Astronomical Society Vol 217;
P805; 1985 &BardenJ. Bond .Jr, Kaiser. N. Eszalay –Journal of Astrophysics).
Galaxies were presumed only to form in the rare peaks of an initial gaussian
distribution of density fluctuation. The average density of universe is roughly
1031gcm-3 which is less than 10% of critical Density( K)
of present universe.[ The matter of
which universe is made of 42.3% is CDM matter and 73% is dark energy]
Density fluctuation peaks that occurred in a potential large-scale cluster
acquired with slight boost that enabled galaxies to form. The biasing
hypothesis enhanced the large-scale structure that developed as gravitational
forces amplified the initial fluctuations. Biasing hypothesis enabled
stimulation of a universe containing “cold Dark Matter” at the critical
density, with observational determination of density perturbation of the universe.
Density Fluctuation was present at the beginning of Time in the earliest
instants of the Big Bang and the Gravity amplified the fluctuations into
large-scale structure of our universe. The “Voids “ were
not really voids but contained matter that had some how failed to become
luminous. The Dark matter was more
uniformly distributed than the luminous matter and does not respond to most
of astronomical tests. The universe is now populated with non-luminous
component of matter (Dark Matter) made of weakly interacting massive
particles which does cluster in galactic scale and designated ΩDM≈0.15-0.35. The dark matter was weakly
interacting and was clustered in all scale (hence labeled as cold). It
selectively formed galaxies at an early epoch in the rare density peaks. The Cosmic Back ground Explorer study announced
on 18th nov’1990 that COBE
had used its liquid helium cooled detectors to make stunningly accurate
measurement of BIG Bang after glow .The
COBE study was based on microwave background radiation that bathes every object
in the universe with a cool wash of photon 2.7K. COBE study conferred that
the Big Bang was a remarkably smooth and homogeneous event. The COBE study
consistently pegged its temperature at about 2.7 K_ what was predicted by Standard
Big Bang Model which holds that radiation was emitted by cosmic fire ball just
a few hundred years after the Big Bang moment it self and cooling off ever
since then. George Smoot[2006 Nobel
Laureate in Physics] and his colleagues of Barkley university used
differential microwave radiometer to look for anisotropic variations in the
brightness of radiation from point to point of the sky. They presumably
corresponded to density variation in the cosmic plasma shortly after the Big
Bang and these variation are in turn presumably the clumps of matter that
CONTRACTED BY GRAVITY TO FORM THE GALAXIES. The problem was that anisotropies
if they existed at all, were so weak that it was hard to see now that how they
had contracted into much of galaxies. Any clump that was going to form a galaxy
needs to be heavy enough to fight cosmic expansion which tends to pull the
material apart almost as fast as gravity can pull it together. COBE showed no anisotropy at all to an
accuracy of one part in 104to one part 105 and it was
DARK MATTER. This Dark matter consisted of some kind of massive but weakly
interacting elementary particles produced in the Big Bang. The cosmic back
ground explorer study(COBE) satellite study was undertaken by leadership of
George Smoot considers the Big Bang very seriously. Microwave Background Study also provided BIG Bang COBE study had
spotted millionth of a degree variations in the temperature of microwave left
over from Big Bang traces of the early universe .Images of the cosmic microwave
background, the radiation left over from the Big Bang, provide the earliest
snapshots of the cosmos—from when it was only about 400,000 years old only The model of MDM of the universe is consistent
with homogeneous inflation theory and large-scale density fluctuation and
galaxies distribution that happened in the early universe. It was the Merry
Gelman, who first described the nature of earliest particles in the universe.
According to her “ it was quark particles in quantum theories.” Actually
speaking, the quest for the early Universe had provided the particle physicists
with an unrivalled accelerator of high-energy particles. The Grand Unification
Theory (GUT) based on ‘Gauge Symmetry” say that Proton (Nucleon) should decay
with half-life of at most 1031 Years. But while isolating the rarest events due to spontaneous decaying of protons, extensive
shielding from atmospheric “ Muon” produced by cosmic rays showers were also
regarded and primary result once was reported at Geneva , Switzerland .
This experiment was carried out us provided in deep underground Kolar Gold
field, Kamoka. This experiment provided us the most sensitive limit so far,
that the half-life of proton is 1.5x 1032years. This half-life of
proton is close to the age of the elements obtained from Radioactive isotopes
~10X109years.This experiments had great implications to
astrophysicists in that 1) possible explanation of ratio of proton to photon in
the universe. Since the photons now seen in 3K-background radiation are the
remnants of equal numbers of particles and antiparticles created during the
thermal equilibrium of first instants of the Universe. This particle was Merry
Gelman’s quark particles and its antiparticles were antiquarks. Today’s
observed proton [matter] represent an excess of matter after antimatter. This
is the asymmetry in Universe. This asymmetry probably had arisen naturally
after 10-35seconds of initial Big bang. However Madsen and Mark
Tailor gave the concept of another particles in the primordial universe. The
name of their particles is ‘ Neutrinos”. There are broadly three (3)
species of ‘Neutrinos”. I) Electron
neutrinos 2) Muon neutrinos 3) and tat neutrinos. To start the universe i.e.
before nucleosynthesis, neutrinos should have a zero mass, which can support at
least a hypothesis and theories of large-scale structure of universe. According
to Maiden and Tailor, the Dark Matter of which this universe consisted of were
the neutrinos and not the quarks.
How did the cosmic Dark Age
ended and when did the first star lit up in the universe in a few hundred
millions years after the Big Bang?
According to the standard Model of Big Bang
Star formation in the early universe was very different from the present now.
Star today form in the giant clouds of molecular gas and dust embedded in the
disk of large galaxies like our milky ways. Where as the first stars evolved
inside “Mini holes” agglomerates of primoriadial gas and dark matter with a
total mass of millions times of our Sun. Another difference arises for the initial
absences of elements, other then hydrogen and helium that were synthesized in
the big bang. Gas clouds today be efficiently via radiation emitted by atoms
molecule or dust grains that contain heavy elements. Because the primoridial
gas lacked those coolants it remained comparatively hot. For gravity to
overcome when the higher thermal pressure, the mass of all first stars must had
been larger as well. The emergence of first stars fundamentally changed the
early universe at the end of cosmic dark ages. Owing to the high masses these
stars were copious. They also produced many ultraviolet photons that were
energetic enough to ionize hydrogen, the most abundant element in the universe.
Thus began the extended process ”re-Ionization” which transformed the universe
from the completely cooled and dark material state into fully ionized medium.
Observation of CMB due to scattering of CMB photons of free electrons, phase constrains
in the onset of re-ionization. How the first stars formed and how they affected
the evolution of cosmos assumes that dark matter is made up of WIMP-yet
undetected because they interact with normal matter only via gravity and weak
nuclear interactions. A possible WIMP candidate is the Neutrions particles, the
lightest super partner in mass super symmetry theory but not zero mass
particles. Super symmetry postulated that for every known particle there must
be a super partner thus affectively doubling mass of the elementary particles.
Most of the super particles that were produced after the Big Bang (including Rupak
particles also] were unstable and decayed. The neutrinos is expected to be
rather massive having roughly the mass of hundred of protons, so are a part of
cosmos.
Most of the matter in the universe did not
interact then with light except gravitationally. These dark matter assumed to
be very intensively cold, that is its velocity dispersion was sufficiently
small for density perturbation imprinted in the early universe to persist in a
very small sale. Dark matter has yet to be detected in the human laboratories.
However there might exist some viable
dark matter candidates from particle physics that were not cold. They may be
termed as Warm Dark Matter(WDM) as per present authors .Warm dark matter
particles had intensive thermal velocities and there motion quench the growth
of structure bellow a “ free streaming scale”{ the distances over which a
typical WDM particles travel}, which depend on the nature of the particle,
because small and dark haloes do not form better then free streaming scale. The
dark matter haloes that formed the galaxies in a WDM model had far less
substructures and were less concentrated as compared to the cold dark
matter(CDM) counterparts. The first generation of stars in the universe formed
when primoridial gas compressed by falling into these small dark matter
potential wells. Large scale partner in the spectrum of density perturbation
causes progenitors of present day clusters of galaxies to be among the first
objects to condense out of the initially almost smooth mass distribution.
Lang Gao & Tom Thennus[science 317:14th
Sept:Page1527:2007] did studied the early star formation in the red shift Z=0
and they concluded that pristine gas heat and it falls into the dark matter
potential Well [halos) cools radiatively because of formation of molecular
hydrogen and became self gravitating. They told
another important particle- called- Gravitinos_ a popular WDM candidate
particle with mass MWDM=3Kev-a. a free streaming particle of few +_ evs of
kelopersec and first stars at red shift Z~200 and the growth structure
re-simulation in the led to a pattern of
filaments and sheets which is familiar form the local large scale distribution
of Galaxies. In assumed Gaussian spectrum of density perturbation appropriate
for an inflationary model lead collapse along one(sheet) and two(filaments) direction before
formation of Haloes. Altogether the large scale filamentary pattern is very
similar in CDM &WDM. This structure of filaments themselves were very
different. The CDM filaments fragmented later into numerous nearly spherical high
density regions(haloes) and WDM filaments fragmented at red shift Z=23.34 when
universe was 140 millions years old. Gas and Dark matter accreted perpendicular
and to filament axis. Dark matter particles falling into filaments performed
damped oscillations as the potential well deepened. Baryons did not under go
orbit but gas compressed to a temperature T~7000K atγ~ 20Pc. Rapid build up of
H2 induced cooling and gas started to dominate the density.
See the following Links also
http://www.sciencenews.org/view/generic/id/48016/description/
http://phys.org/news162651549.html
http://mnras.oxfordjournals.org/content/378/2/449.full.pd
http://www.firstgalaxies.org/the-early-universe
http://www.sciencenews.org/view/generic/id/48016/description/
See the following Links also
http://www.sciencenews.org/view/generic/id/48016/description/
http://phys.org/news162651549.html
http://mnras.oxfordjournals.org/content/378/2/449.full.pd
http://www.firstgalaxies.org/the-early-universe
http://www.sciencenews.org/view/generic/id/48016/description/
Copy right- The copy right of this article strictly reserved to Professor Pranab Kumar Bhattacharya and otherauthors as in chronological order as per Intellectual Property Right(IPR) copy
Right Rules 3D, 107; 1201 (a) (b) RDF and SPARC-2006 Copy Right Rules. Be highly enough care full for plagiarism suit of any kind and Do not try to infringe it to
avoid huge infringement & damage
suit in IPR court of laws .
Friday, 29 March 2013
The evolution of Spiral Galaxies in the observable universe – Author’s views
Authors_;
* Authors are_:
*Mr. Rupak Bhattacharya-Bsc(cal), Msc(JU), of residences 7/51Purbapalli, Sodepur, Dist 24 Parganas(north) Kol-110,West Bengal, India**ProfessorPranab kumar Bhattacharya- MD(cal), FIC Path(Ind), Professor and HOD of Pathology convener in-charge of DCP and DLT course of WBUHS, , Calcutta school of Tropical Medicine, 108, CR Avenue, KOlkata-73 , West Bengal, India, Ex- Professor and HOD Ophthalmic pathology, RIO KOl-73, Ex professor of Pathology WBUHS and EX Add. Professor IPGME&R KOl-20 W.B, India** Miss Upasana Bhattacharya – only daughter of Professor Pranab Kumar Bhattacharya of mahamaya Apartment Mahamyatala, Garia kol-84 *Mr.RitwikBhattacharya B.com(cal), *Miss Rupsa Bhattacharya-,* Mr Soumyak Bhattacharya BHM(cal) MSC(student) PUSHA, New Delhi, all of residence 7/51 Purbapalli, Sodepur, Dist 24 parganas(north) ,Kolkata-110,WestBengal, India*** Mrs. Dalia Mukherjee BA(hons) Cal, Swamiji Road, South Habra, 24 Parganas(north) West Bengal, India*** Mrs Dalia Mukherjee BA(hons) Cal cutta university, ***Miss Oaindrila Mukherjee- BA(hons) Student Cal Univ, ***Mr Debasis Mukherjee BSC(cal) ,Swamiji Road, South Habra, 24 Parganas(north), West Bengal, India
*Mr. Rupak Bhattacharya-Bsc(cal), Msc(JU), of residences 7/51Purbapalli, Sodepur, Dist 24 Parganas(north) Kol-110,West Bengal, India**ProfessorPranab kumar Bhattacharya- MD(cal), FIC Path(Ind), Professor and HOD of Pathology convener in-charge of DCP and DLT course of WBUHS, , Calcutta school of Tropical Medicine, 108, CR Avenue, KOlkata-73 , West Bengal, India, Ex- Professor and HOD Ophthalmic pathology, RIO KOl-73, Ex professor of Pathology WBUHS and EX Add. Professor IPGME&R KOl-20 W.B, India** Miss Upasana Bhattacharya – only daughter of Professor Pranab Kumar Bhattacharya of mahamaya Apartment Mahamyatala, Garia kol-84 *Mr.RitwikBhattacharya B.com(cal), *Miss Rupsa Bhattacharya-,* Mr Soumyak Bhattacharya BHM(cal) MSC(student) PUSHA, New Delhi, all of residence 7/51 Purbapalli, Sodepur, Dist 24 parganas(north) ,Kolkata-110,WestBengal, India*** Mrs. Dalia Mukherjee BA(hons) Cal, Swamiji Road, South Habra, 24 Parganas(north) West Bengal, India*** Mrs Dalia Mukherjee BA(hons) Cal cutta university, ***Miss Oaindrila Mukherjee- BA(hons) Student Cal Univ, ***Mr Debasis Mukherjee BSC(cal) ,Swamiji Road, South Habra, 24 Parganas(north), West Bengal, India
There are about 1018
million of galaxies in the Universe, and there exist vast empty 3D
dimensional space-time is between them. How much distance from one galaxy to
another? "Cephids" can be used as a distant indicator to about 10 million light
years, which is equivalent to 4 million persec. These galaxies are
distributed through out the Universe. Galaxies are of different type and
configurations. Some are spiral galaxies, some are
non-spiral galaxies Amongst all the galaxies in the Universe, a
small minority of the galaxies are spiral galaxies i.e. disc shaped galaxies
(some are again of thin disc and some are of thick disc). There are non spiral
galaxies also and most of the galaxies in the
Universe are of non spiral (without disc) and majority of them are elliptical
galaxies and rare verities are lenticular galaxies. Our "Milky
way" is the local group of spiral galaxies. It is our home galaxy. Our Milky way galaxy is a spiral galaxy – a massive and a big galaxy
at least 250 billions of solar mass MO and is a disk like of a diameter 100,000
light years. The light at its speed cross from one end to another
end takes almost one lack years. It consists beside trillions numbers of stars contain also 1022
planets and thousands of clusters of nebulae (nebulae are of various
types like diffuse nebulae, planetary nebulae, supernova remnants, and dark
nebulae), supernovas
and globular clusters. The mass
of the Milky way is probably in between 750 billion & one trillions of
solar mass. Milky
way is a spial galaxy of Hubble Sb or Sc type. So Milky Way has pronounced disk
component exhibiting the spiral structure and a prominent nuclear region, which
is a part of a notable buldge/ halo component. Milky way galaxy belongs to
local group, a smaller group of three large and over 30 small galaxies and
second largest galaxy in the universe. Milky way galaxy contain many clusters of galaxies.
They are 1) Mosiac of Milky way extending from
Saggittarius galaxy to Cassiopeia
Galaxy. 2 Ophiuchus galaxy and 2 globular clusters 3)Theta Ophiuchi 4) Scorpius
& saggituris galaxy 5) Serpens 6) starclouds in Sagittarius 7) Sagittarius M8 8) Aquita & Sagittarius
M69) Western Aquita 10) Gamma Cygni galaxy 11)
Alpha cygni galaxy and so many. The milky way appears to be brightest in
the direction of Sagittarius where the galactic center lies. Relative to the
celestial equator, the Milky Way passes as far north as the constellation of
Cassiopeia and as far south as the constellation of Crux. This reflex the fact
that the earth axis of rotation is highly inclined to the normal to the
galactic plane The galactic disk of milky way has a diameter of about 100,000
light years, The
distance from our Sun to the galactic center of our Milky way is about 27,7000
light years. The center of our galaxy is one of the highest infra
Red sources of sky. It is about thousands time brighter in the infrared then in
radio wave length. Infra
red observation show that the center of our Milky Way is orbiting very rapidly. The
center of Milky way is not visible at optical wave length because it is hidden
behind numerous clouds of star gas and dusts. However we can view the center of
Milky Way at infrared sources as infrared can easily penetrate gas and dusts. The
Milky Way contain over 200 billions numbers of stars more massive then our sun.
The amount of mass inside suns orbiting only around galactic center is
9.0x1016M0. The stars in the galactic disk rotate around
galaxy’s center, which is suspected to harbor a super massive black hole. There are believed to be
four-mazor spiral arm and at least two smaller arms, which all start at the
galaxy’s center. They are named as follows 1) Norma arms 2) Scutum arm 3)
Sagittarius arm 4) Orion arm 5) Pursues arm 6) outer arm. The distance between the local arm to the next arm’ Peruses
arm” is about 65,000 light years. Each spiral arm describes a logthermic
spiral. The disk is surrounded by halo of old stars and globular
clusters. Our sun is located at an extreme distance of the disk. The disk of
the milky way has four spiral arms that we described a little ago. The disk is
approximately 300 Pc thick and 30KPc in diameter. It is made up of
predominantly of Population I star [see star formation] which tends to be blue
stars and reasonably spanning an age range between a million and ten billions
years old. The buldge at the center of Milky Way is a flattened spheroid of
dimension of 1KPc /6KPc. This is a high density region with population II stars
which tends towards red and are very old stars about 10 billions years old. The
halo, which is a spherical region surround the disk .It, has low density of old
stars mainly in form of globular clusters [each globular clusters consist of
stars between 10,000- 1lack]. The halo is believed to be composed of mainly
cold dark matter 9CDM) which may extend beyond the edge of the disk. The local
group of galaxies is probably millions of light years away from our A.G.N.
When Did the First Cosmic Structures Form as
galaxy? Quasars
are probably the first cosmic structure probably formed in our cosmos . Quasars are most distant and distinct
objects that astronomers have been able to directly detect. Because of their
intrinsic brightness, the most distant quasars are seen at a time when the
universe was one tenth of its present age, roughly a billion years after the Big Bang
moment . However, astronomers believe that some objects must have
formed earlier than quasars, because the ambient gas in the universe is
observed to be ionized
at a relatively early time, presumably due to ionizing radiation from a
population of early objects. Since ionized gas can interact with cosmic
microwave background photons, WMAP observations help to elucidate the nature of the ionized gas
and the objects that caused the ionization. Since light travels at a finite
speed, distant objects are seen as they existed in the past. We see the Sun not
as it is now, but how it was just eight minutes ago. (The so the Sun which we see at a moment time today
is eight light minutes away from the Earth). We see the nearby stars as they
were several years ago. We see Andromeda, the nearest spiral galaxy as it was
roughly 2.5 million years ago how it was . Thus, the most distant objects that
we see are the oldest objects that we can directly detect.
What is Quasars?
Quasars
are the most distant distinct objects that astronomers have been able to detect. In
a region smaller than our solar system, a quasar in fact emits more & more light than our
total entire Milky Way galaxy emits light.
Can you imagine that ? But Quasars are again believed
to be super massive black holes, whose masses exceed that of a million Suns,
and whose pull is swallowing gas and stars from their host galaxies. Then black
holes also emits light. They do shine brightly by converting the gravitational
energy of the in falling Astronomers and physicists are not till date certain
what objects ionized the gas(Mixed dark matter oe WIMP) in the early universe
nor do they know at what time this ionization occurred. Some speculate that an
early generation of massive stars ionized the
gas. Others speculate that most galaxies contain super massive black holes and
that the formation of these super massive black holes illuminated the early
universe. When Was then Gas Ionized is
our question ? While observations of quasars enable astronomers to infer that the gas
was ionized within the first billion years of the universe, we need to observe
something more distant than quasars to learn when the gas was first ionized: the cosmic
microwave background radiation. Since
the cosmic microwave background photons were emitted roughly 380,000 years
after the Big Bang, much earlier than the photons from quasars, their
properties tell us about the subsequent evolutionary history of the universe.
Microwave photons move freely through neutral gas, but they scatter off of
ionized gas. This scattering reduces the amplitude of fluctuations
in the temperature of the cosmic microwave background and produces new
"polarized" microwave background fluctuations.
material into light. The
most distant quasars are seen at a time when the universe was one tenth its
present age, roughly a billion years after the Big BangWhat Ionized the Gas in the Early Universe? Scattered light is often polarized. On a bright day, we see not only sunlight directly from the Sun, but also light that scatters off of dust in the air. This scattered light, or "glare", is polarized and can thus be filtered out by a good pair of polarized sunglasses. Similarly, scattered cosmic microwave background photons are polarized by scattering off of free electrons in the early universe. WMAP is designed to detect polarized photons. In principal, their properties reveal the number of free electrons in the early universe and the ionization history of the universe. This enables astronomers to infer that the first objects in the universe capable of ionizing the gas formed at about 200 million years after the Big Bang. We hope that the time history of the ionization will help determine the nature of these first objects
How the spiral galaxies were formed? Before formation of the galaxies, there were pre galactic clouds which is consisted of gaseous substance. Sir James Jeans first proposed that when the same density perturbation exist in the homogenous gas clouds and when clouds exceeds a certain limit, the cloud suffer an instability. As a result the cloud begins to collapse. The Jeans critical mass (Mj) was described as follows.
MJ=1023(T/U)3/2-1/2p
gm
[Where
"P" is the density, "T" is the Temperature and fl is
the mean molecular weight of cloud. ]
The pre galactic
gaseous mass were above the critical mass and as a result this pre galactic
gaseous clouds collapsed owing to density perturbation. The mass of discrete
such clouds was about 1014-1015 MO which is typical for
the mass of super cluster in the present Universe. Now the
fragmentation process carried on within the super clusters. The denser central
region of the collapsing gas cloud collapsed more rapidly than the outer
region and became more and more dense. Ultimately it became so compact that
instability set in and it was fragmented in pieces. Each individual fragment
continued to collapse and was re fragmented and the process went on until star
formation set in. Thus Super clusters collapsed and fragmented resulting
cluster of galaxies which in course of time again fragmented into galaxies. -If
further fragmentation would continue, one would star clusters from where baby
stars generated. If we observe today at high galactic latitude, we can see
hydrogen clouds .concentrated in a thin layer around the galactic plane, which
is moving with a very fast velocity about 5 Km S-I. There are
several such gaseous clouds with very high velocity up to 200 Km S-I.
The distributions of gases are extremely uneven. It is concentrated in clouds
(dark matters) of different sizes. This cloud matter are probably still in
extra galactic system or even in the protogalactic system. Now, the
spiral galaxy system evolution resulted when the protogalactic gasses or clouds
detached itself from the surrounding Universe. They then gained angular momentum,
at the moment of their detachment. There was a minimum radius for the
"cell" bellow which it no longer contained the necessary angular
momentum. For our spiral galaxy "Milky way" the minimum radius
reached, suppose at the time "t" when the radius of the Universe
"p" was about 1/25th of the present radius Ro. And that was the time
when the "Cell" spiral galaxy had a large amount of angular momentum.
There was of course radial stream momentum as well as transverse stream
momentum in the cell. All these momentum resulted initiation of rotation. The
angular momentum in the "Cell" containing cloud gasses gave spiral
galaxy due to the collapse of the part of the gas, (Fig-I) It happened probably
at the time of about 109 years, a little shorter then the age of the
Universe 1010 years (1000 billion years). The radial stream
force should diminish the Universe expansion locally. They will not in 'general
eliminate it entirely and so the spiral galaxy will expand some time. But it
will also collapse again, due to angular momentum in about again 109 years
beyond the present time. Now the question remain to us if the galaxies would be
formed where the velocity gradient happened to be favorable for spiral
galaxies, then there may be many other areas where no such function was
possible. So then, in those areas, we should have direct evidence of inter
galactic matter. There must be considerable quantities of C D M matter in the
local group galaxies, besides that they concentrated in galaxy. The "Milky
way" galaxy is such a spiral arm galaxy. The spiral arm structure of
our galaxy can be traced by radio wave -demonstration of interstellar hydrogen
at a wave length 21 cm where neutral hydrogen is used as a tracer element to
delineate the spiral arm and the galactic disks, in which gasses are largely
concentrated. By these study, the position of various concentration of.
Hydrogen, which can be seen in each line of sign are indicatated by filled
circles. A series of small open circles correspond to a broad peak on the
profile indicate a spiral arm. There are significant differences in the neutral
hydrogen distribution on the two side of the galaxy. In the outer region, the
peaks of the spiral arm are less pronounced on the southern side of the galaxy
then they are on the northern side. This galaxy shows multi armed structure.
The arm shows geometrical trailing tendency clock wise. The neutral hydrogen is
confined mostly in the thin layer in the galactic disc.
The Active galactic
neucleus (AGN) like other spiral galaxies, is the central
region of our galaxy. What is present at the center?
It
is yet a great puzzle to us. There are many theories. A bright quarser! A black
hole! A neutron star! Or globular clusters! The concept that the center of our
galaxy might explode with the violence of a bright quarsar, by "Lorry
Niven" in his book "Ring World" (Gollancz publishers-1970).
According to him, this galaxy will turn into a quarsar, and once, the blast of
light, electromagnetic radiations and very high energy particles will reach to
us. Since, we orbit round the center of our galaxy, at a distance of about 10
Kilo Persec, then it is however possible that the nucleus of our galaxy had
already exploded in the past 30,000 years and we have not yet know about it.
The light from such an explosion along with cosmic ray particles will take much
long time to reach to us. And if this happened in reality in past time, then the
blast particles from the quarser at the center of our galaxy, as soon as will
reach to us, will destroy the total civilization. It may happen on any day, any
time. The center region of our galaxy, like the central region of other spiral
galaxies contain globular clusters. However the feature is consistent with the
elliptical galaxies "Spherical type". These globular cluster contain
the oldest stars of the galaxy, and their formation was clearly related to the
formation of the first component of our galaxy as we have told early, Then one
question appears to us "is it the fact that all the galaxies forming, at
initial phase were elliptical one? and then under gravitational influence of
central retarded core, some of them turned into spiral galaxies? Then another
question appears to us, where from the material came for formation of disc of
the spiral galaxy?
How could these
globular clusters form at AGN? The another big question!
The Conventional view is that they were
produced by collapse of greater region of self gravitating gasses that became
spiral galaxy as we have shown in above picture (Fig. 1). And if we take the
concept of globular clusters at our AGN, there remains no possibility of
explosion of our AGN. like that of a "quarser" or "Sey fert
galaxies". These bright globular clusters were formed at the earliest
stage of the development of our galaxy, and these globular clusters are
brightest at a distance 30,000 light years. (It is the distance of ours, from
galactic center, at some direction). Each globular clusters were formed of tens
of thousands of stars, and more than few hundred globular clusters are
associated with AGN of our "Milky Way”. The most exciting theory is
"Black hole" at the center of our spiral galaxy. Where from the black
holes came in center? Then black holes has to be originated in the birth
time of the galaxy or in the "Big Bang" time, or the black
holes grew from the globular cluster? The x-ray sources have now been
identified with globular clusters, and this has encouraged the speculation that
there might be a massive black holes like "SgRA" at our galactic
nucleus. The Globular clusters show no sign of exploding like "Sey
fert" galaxies, or quarsers and may stay retarded for ever as simple
massive black hole or perhaps they burst their bounds very soon after the
"Big Bang" in the galaxy and settled down into a long life of
respectability as quiet collapsed objects. Our spiral galaxy has a dark halo
extending 50 KPC to 100 KPC at its center. The shape of the halo is unknown.
The gamma ray observatory (GRO) satellite found distribution of γ-ray on the
sky and the γ ray burst was isotropic. The source of the gamma ray is
non solar origin and is either in an extended galactic halo or at cosmological
distance. So the most conservative
approach is to assume that the halo at the center of our galaxy is of old
population of type II accreting neutron stars and thus the halo emits y ray
bursts. The distribution of neutron stars have an isotropic
distribution in the galactic center. Our
galaxy have spiral arms. Successful efforts to trace the spiral
structure of our galaxy began in 1940s. Spectroscopic studies show that spiral arms themselves are made of mainly
neutral hydrogen gasses and young hot stars. Measuring directly the
concentration of hydrogen gas by its emission at 21 cm wave length. Our spiral
arms show to contain huge concentration of hydrogen gasses. Other method of
tracing the spiral structure is (1) tracing
the young stars (0 and B stars). They are so common in our spiral
structure, as if they are lighting the path of the spiral structure, like
street lamps lighting a twisted road. (2) Co line luminosity of the spiral
structure. Hydrogen mass of the galaxy can be calculated from the co line
luminosity of a galaxy accordingly MH2/L’co = (4u/3π G)1/2(n
(H2)1/2Tb), where (4μ/3μG)1/2 =2.1 MΘ
(K. KmS-1Pc2)-1cm3/2K and n (H2) is the
hydrogen density (P Solomon-Nature vol. 356, P. 318-19, 1992). Our galaxy
contain trillions of stars.
Our
galaxy has a spin rotation. Every spiral galaxies does rotate. Elliptical
galaxies do not rotate very much. Our "Milky Way" is a very slow
rotating galaxy. It rotates in its spiral arm "a few cm", once in
every 10 million years. Where from the rotation came? Who set the
spiral galaxies to rotate? It is the Soviet Astronomer V.A. Ambartsumian, who
gave a theory that galaxies are formed by a process of ejection from the
parent galaxies, by a violent outbursts from the galactic nuclei, he told that
spiral galaxies form in pairs, and that when two nuclei from one cosmic gusher
to become the new pair of spirals, they split up with opposite rotation,
relative to each other due to equal and opposite amount of angular momentum.
So in that case there must be a link material or link bridge between the two
spiral galaxy and each spiral galaxy must contain its companion galaxy. The
"Whirlpool galaxy" M51 with its companion is the classical
example of such a theory of Ambartsumian. Actually M 51 first revealed the
astronomers about the existence of other spiral galaxies in the Universe. It
has a very clear, beautiful spiral pattern, with bright young stars, edged by a
lane of dark material, sweeping out from the center in two opposite arms. This
M 61 has a bridge material which extends from one of the spiral arm to its companion
galaxy, small and bright, made of same kind of materials. The spiral arm of M51
is radio spiral, and two strong spiral arms running along the inner edge of the
spiral pattern of bright young (0 & B stars) stars. The spiral arm contain
great quantities of neutral hydrogen gas, like ours "Milky way". The
radio evidence also clearly reveals that lane of hydrogen gasses extended
across the bridge to its companion galaxy. This companion galaxy makes the end
of one of the two major spiral arms. But the difficulties of Ambartsumian
theory is that our galaxy and majority of spiral galaxies has no companion
galaxy like M51
Our spiral galaxy is not any thing new or special in the
Universe. Besides our "Milky way", there are at least 63 spiral
galaxies (Catalogued so far) known, who have velocities 800 Kms.l. Spiral
structures has also variability, some are tightly wound, others are open
spirals. IRAS study has detected a spiral galaxy with a distant red shift
Z=2.286. It is IRAS 10214+4724 galaxy with most intrinsically luminous objects
in the universe α=1014LΘ (LΘ=Solar luminosity) The total mass of
neutral molecular hydrogen in the IRAS 10214+4724 is 2-6 X 1011 M0. This mass
is compatible to total mass of a large spiral galaxy. "Co luminosity is
recent technique to estimate the H2 mass in the spiral galaxy, and IRAS
10214+4724 galaxy has a Co luminosity at least 20 times than that of local
group galaxy. Its hydrogen mass is roughly equal to total mass of large spiral
galaxy like the "Milky way" (P.M. Solomon Nature vol 356, 26th March
P. 318-19, 1992). 90% of the galaxy contain stars and 10% gasses (The total
agglomeration of molecular gas in Milky way is 106-107
M0).
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Tribute & Acknowledgement- To
our late parent diseased late Mr. Bholanath Bhattacharya B.com(cal) FCA(India)
SAS(India) and late Mrs Bani
Bhattacharya House wife of their residence 7/51 Purbapalli, Po-Sodepur, Dist 24
parganas (north) , Kolkata-110,WestBengal, India, for their initial teaching for us about the universe, Big Bang galaxy
stars and the eternity
Copy Right- Copy Right of this article is the intellectual Property and Copy Right of the article belongs to Professor Pranab kumar Bhattacharya and his first degree relatives only as per copy right act & rules of Intellectual Property Right Rules 3D/107/1201 a,b/ RDF Copy Right rules/ SPARC copy Right rules-2006/ and Protect intellectual Property Right(PIP) copy right rules of USA-2012.Please do not even try to Infringe and be enough careful for your own safety if you are not direct Blood relation to prof Pranab Kumar Bhattacharya . No person, No NGOS [ except the authors& first degree relatives] in the state of West Bengal or in any states of India or in any abroad countries are authorized to use this article, with any meaning full, scientific sentences or with scientific and meaning full words laid out in this article either in the class room/ or in mass teaching programme including CME or in any form what so ever it is with any content of this article or while in writing any book or for his/her personal/ home use, or collective works or for any future Research or implementation as a policy matter or,[ except the authors ]or by Xeroxing and distributing the article/ or by printing/saving/broadcasting the article from any website of internet services,displayed without proper copy right clearance from the authors or from his family members or future copy right owner by written forms.
Sd/ Professor Pranab Kumar Bhattacharya WBMES
Sd/ Professor Pranab Kumar Bhattacharya WBMES
Friday, 8 March 2013
Blogs of Professor Pranab Kumar Bhattacharyya MD(cal) Pathology; : supernovas and mechanism of explosion of supernova...
Blogs of Professor Pranab Kumar Bhattacharyya MD(cal) Pathology; : supernovas and mechanism of explosion of supernova...: Authors_; * Mr. Rupak Bhattacharya -Bsc( Calcutta Univ. ) Msc(Jadav Pur Univ) of Residence 7/51 Purbapalli,PO-Sodepur...
supernovas and mechanism of explosion of supernovas
Authors_;
**Miss
Upasana Bhattacharya- Only Daughter of
Professor Pranab kumar Bhattacharya,
Student, Mahamya apartment; Block B, Mahamyatala, 54 NSC Bose Road;
Garia, kol-84. WB, India
**Professor
Pranab kumar Bhattacharya MD (Calcutta
univ.) FIC
Path(India); Professor and Head, Department of Pathology, School of Tropical Medicine-kolkata; 108, C.R Avenue ,Kolkata-73, WB, India; Ex- Professor
and HOD Ophthalmic Pathology RIO kolkata-73, & of WBUHS and Ex- Professor
of Institute of Post Graduate Medical Education & Research,244 AJC Bose
Road, Kolkata-20, West Bengal, India{
Member & Member Secretary of Board of Studies of West Bengal University of Health
Sciences(WBUHS), DD36, Salt Lake City Sector-1, kolkata, West Bengal for Undergraduate, Post Graduate and Post
Doctoral studies in Pathology and of DCP
courses under WBUHS. Examiner of Post Doc PhD & Thesis Evaluator Adjudicator of MD/DM/PhD of
WBUHS
***Mr.Ritwik Bhattacharya B.com(calcutta Univ) *** Miss Rupsa Bhattacharya *** Mr Soumyak Bhattacharya
BHM(IGNOU], MSc student PUSHA Govt of India, New Delhi , India
,
* & *** 7/51 purbapalli, Po-sodepur Dist 24
parganas(north) , Kolkata-110,WestBengal ,
India
**** Mrs. Dalia Mukherjee BA(honors)
Cal.Univ **** Oaindrila Mukherjee- BA Honors(English) cal univ; Miss Oaeshi
Mukherjee- Student **** Mr Debasis
Mukherjee BSc(Calcutta Univ) of
Residence Swamiji Road, South Habra, 24
Parganas(north), West Bengal, India
What is the fate of this
Universe?
Cosmos is Expanding
It is not the first time that an astronomical discovery has revolutionized
our ideas about our Universe. Only a hundred years ago, the Universe was
considered to be a calm and a peaceful place, no larger than our own galaxy,
the Milky Way. The cosmological clock was then as if ticking reliably and
steadily and the Universe was eternal. Soon, however, a radical shift changed
this picture. At the beginning of the 20th century the American amateur lady
astronomer “Henrietta Swan Leavitt” found a way of measuring distances to far away
stars. At the time, some women
astronomers were denied access to the large telescopes, but they were then
frequently employed for the cumbersome tasks of analyzing photographic plates
taken of these large telescopes. Henrietta Leavitt had thus enjoyed enough scope of analyzing
& she could havoc
scope of studying thousands of pulsating stars, they called them “Cepheids”,
and she found that the brighter ones had longer pulses. Using this information,
Leavitt could calculate the intrinsic brightness of Cepheids and it was
immediately accepted by rest of world. She told ,If the distance of just one of the
Cepheid stars is known, the distances to other Cepheids can be established –
the dimmer its light, the farther away the star is”. A reliable standard candle
thus was born, a first mark on the cosmic yard stick that is still being used
today. By making use of Cepheids, astronomers would soon concluded that the “Milky
Way” is just one of many millions galaxies in our observable Universe. And in
the 1920s, the astronomers got access to the world’s then-largest telescope
Mount Wilson in California ,
so they were able to show that almost all galaxies are in fact moving away from
us. Wao! It was astonishing discovery in Astronomical science &Physics!.
The concept of Red shift(z). They were
then studying the so-called “redshift”(Z)
that occurs when a source of light is receding from us. The light’s
wavelength gets stretched, and the longer the wave, the redder becomes its color
was the theory behind it. What ever may be, the conclusion was that all the
galaxies are rushing away from us and each other, and the farther away they
are, the faster they move – this is known today as Hubble’s
law. The Universe is growing [2].
The coming and going of the cosmological constant
What was observed in
space time had already been suggested by
theoretical calculations. In 1915, the great intelligence & mind Nobel Laureates in physics “Albert
Einstein” published his “General Theory of Relativity”, which had been the
foundation of our understanding of the Universe ever since the publication. The theory described a Universe that has to
either shrink ( Big Crunch)or to
expand. It was really a disturbing conclusion for mathematician. This
disturbing conclusion was reached about a decade before the discovery of the
ever-fleeing away galaxies. Not even
Einstein could reconcile the fact that the Universe was not static ( steady
State theory of JB Narleiker and Fred Howel-
Nobel laureates in physics). So in order to stop this unwanted cosmic
expansion, Einstein had no other option
but to add a constant to his equations that he himself called the cosmological constant.
Later, Einstein would consider the insertion of the cosmological constant was
in fact
a big mistake for him.
However, with the observations made in 1997–1998 that are awarded the 2011
Nobel Prize in Physics, we can conclude that Einstein’s cosmological constant
– put in for the wrong reasons – was actually brilliant one thought in fact. The
discovery of the expanding Universe was a groundbreaking first step towards the
now standard view that the Universe was created in the Big Bang almost 14
billion years ago. Both time and space began only then. Ever since, the Universe has been expanding; like raisins in a raisin cake swelling in
the oven, But No body still answered what is beyond that Planck’s moment of
Big Bang Creation of our universe?. Was there another universe? Was there
multiple universe?
Stars last too
long in the universe.
For an amateur astronomers/ or theoretical
physicist like myself and my brother Mr Rupak
Bhattacharya, to see any evolution of a star or death of a star, in the course
of his/their life time, unless he/they is/are lucky enough to see one star
destroying itself in a phenomenon called
supernova or in a nova explosion or turning towards a Red giant .
My then old and diseased father[ He was diseased in 2009 April] , late Mr.
Bholanath Bhattacharjee and my mom late Mrs Bani Bhattacharya ( She was
diseased in May 2006) of our residence7/51 Purbapali, Po-sodepur,24
parganas (north) kolkata-110, West Bengal, India , they used to teach our
brothers and only sister in our younger
ages, child ages, with their built up notion like this”….. Stars are long lived
objects with ages, they are as old as our galaxy is, as old as our universe is
and they are symbol of eternity [heaven and hell their Planets are] they may be
2.5 billion years – 3 billion years old from a first generation stars explosions and are almost perfect cosmic mile markers even very
close to Big Bang. And many such stars might have habitable planets like our Earth
where civilization grew but better form of technological civilization exists
there and we intelligent human beings come from there and returns back after
our death there according our acts in this planet. They belived in soul ! God!
Creator! Big Bang! Today we know that looking at a supernova of
a very distant star almost at horizon of the universe, or of a Nebula, we can
understand the mystery of creation of the Universe, the Big Bang it self. They
are really the symbol of the eternity.
Edington suspected, that the nuclear reactions in the interior of the
stars are primary sources of energy for it’s luminosity and fusion of
hydrogen to make Helium and that can take place in it, in time bound scale for
this ranges, from millions to millions years. Our sun has lost it’s
brightness by more then 1% from it’s birth, due to change in it’s internal
structure for past 107 years. But the question remains how these supernovas explode? What is the
mechanism behind it? No physics probably
answered it yet. Here
may be some explanations by my brothers
Rupak Bhattacharya and Ritwik Bhattacharya
the authors
If
we consider the mode of generation of energy in the star, nuclear process
provide the only source of energy adequate to keep the stars ongoing luminous. The
nuclear fusion in which Hydrogen is built up into Helium, can function
sufficient fast at temperature, like those at central core of star (12-25
million degrees). The Helium burning process are important 1) Carbon
Nitrogen cycle at which a carbon-12 nucleus (12C) capture proton
and is converted into 13C, Nitrogen-4 and nitrogen –15. At a
final temperature, a proton leads to a fusion yielding original 12C
nucleus to a Helium nucleus .2) The Proton- Proton process, in which
protons are built direct Helium nuclei through steps, involving first in
production of a deuterium and helium3 nuclei to form Helium4
nucleus and two protons. 3) Carbon burning process where 12C
nucleus undergoes fusion reaction in the interior of a star producing neutron,
proton, and Alfa particles with huge temperature. The first reaction probably
dominates into the star, applicable to more massive stars then Sun. The
second and third reaction is applicable for Sun and in less massive stars then
Sun respectively. Thermonuclear reactions like those in a hydrogen bomb are
powering the Sun in a contained and continuous explosions converting some four
hundred millions tons (4x1014 grams) of hydrogen into helium. When
we look up in the sky in night and see the stars we see them shining because of
distant nuclear fusion in them .But hydrogen fusion can not continue for
ever. Our Sun is ~ 4.7109 years
old star. The energy produced in our ordinary star Sun in each second, is
equivalent to the destruction of 41/2 millions tons of hydrogen mass in every
second, a mere fleabite compared with the mass of the Sun which is two thousand
billion and billion tones. In the Sun or in any other stars, there is limited
so much hydrogen in it’s hot interior. Although Helium is predominating as
net fusing of Hydrogen, other elements like “carbon”, “Iron”, “L
element” “Manganese” “Chromium”, EU, yttrium, Magnesium, SR, Nickel,
Osmium are also built up in the interior of the stars. Arnett and Truran
[Arnett W.D and Truran. JW –Astrophysics.J-Vol157;P339,1969] showed
that nuclear reaction net work in the sun when 12C nuclei began to under go the fusion reaction in
the interior of sun many elements are produced such as
12C+12C
à
23Na+P+2.238mev à23Mg+
n+2.623mev-à20Ne+ 27Al
+4.616mev and the reaction goes on endlessly. A large number of computed
reactions are possible as the liberated neutron and gamma particles begin reaction
with all the nuclear species generated within the hydrogen fusion. In fact
Arnett and Truran produced 99 different reactions only in 12C carbon
burning net work and 23Na,20Ne,
24Mg,27Al,29Si, and some31P elements are also produced. Beside these
Li, Be, B ( Known as leptons)are also produced in the stars due to hydrogen
burning. Another more most elementary particles are produced in huge
quantities. They are called Neutrinos or ghost particles due to hydrogen
burning procedure ( Professor Pranab Bhattacharya & Mr. Rupak
Bhattacharyya). Conversion of hydrogen into helium in the center of the
stars or of the Sun, not only accounts for Sun’s brightness in photons of
visible light. It also produces a radiance of a more ghostly kind. The sun
glows faintly in neutrinos , which like
photons, weight nothing and travel at speed of light. Neutrinos emitted from
Sun carry an intrinsic angular momentum or spin while photons has no spin.
Matter is transparent to neutrinos which can pass effortlessly through the earth
and through the Sun. Only a tiny fraction of them is stopped by intervening
matter. As you look up our sun, a billions neutrinos pass through your eye
ball. They are not stopped by Retina as ordinary photons do ,but continue
unmolested through the back of your head. The curious part is that if at night
if I look down at ground, towards the place where sun would be, almost exactly
same numbers of solar neutrinos pass through my eye ball, pouring through an
interposed earth which is as transparent to neutrinos as a plane of clear glass
is to visible light. Neutrinos on very rare occasion convert chlorine atoms
into argon atoms with the same number of protons and neutrons. Davis first used a
beautiful technique of Pontecours and Alvarez based on the reaction 37C1(V,e-)37Ar
to place an upper limit on the solar neutrinos flux on earth
The
previous view regarding the “L atoms elements” was that each star makes it’s own share of these “L
atoms elements”i.e (autogenously origin). But the concept of autogenic view has
been now abandoned, because highest abundance values for stellar Li & Be
have shown to be not larger than interstellar upper limit. The formation of
each “L atoms” requires the acceleration of about 1erg fast proton. To account
auto genetically for lithium abundance in T. Tauri stars (L1/H=109),
the time integrated amount production of energy into particle acceleration must
be comparable with gravitational release, implying an unlikely high efficiency
for acceleration mechanism. So nuclear mechanism is responsible for
generation of “L atoms” in the star. It involves high-energy process
(Thermonuclear reactions). These L atoms” can be formed in two different
ways within the stellar interiors. By the collision of
incident light particles on the heavier atoms of interstellar gas
(For instance fast protons on stationary C, N, O) or the reverse (for
instance fast C, N, O on hydrogen at rest). In the first case the Products “ L
atoms are to remain in rest, while in the second case, the products are moving
at a velocity comparable with that of cosmic rays. The fate of “ L atoms” generated by fast protons on
stationary C, N, O stationary atoms and are all rapidly thermalised and become
part of ISM.
“L
atoms” generated by reverse process have a fate which depends on the initial
energy of “L atoms”. L atoms with energy E<0.2 Gev nucleon-1 will
stop in galactic gas (ISM) while L atoms with E > 0.3Gev neucleon-1
will suffer nuclear transformation of various elements in the stellar interior.
Analysis
of Old stars can give us some idea that heavy elements are produced in the
interior of the stars and are subsequently ejected into the ISM either through
the supernova explosion or through stellar winds or through cosmic rays. The total
mass loss, from all stars in a galaxy will be roughly 1MO per year. A fraction
of these accumulate in the galactic nuclei, which are center of the
gravitational attraction. The halo of our galaxy is nearly spherical region
containing very old stars, which have a smaller content of heavy elements than
our sun has. It is usually assumed that some how cloud of gas condensed to form
our galaxy and that the halo stars were formed during the collapse process
and left with a nearly spherical distribution. These stars are ultra high
velocity stars. These stars show weak spectral lines corresponding to abundance
of carbon and heavier elements [relative to hydrogen] that are lower than our
Sun. Because these stars are oldest in our galaxy quite distinct type of
nuclear process have been postulated for different groups of elements. The most
abundant nuclei are 32S and 58Fe those can be formed by
silicon burning process while 16O, 20Ne,23Na 24Mg,28S
may be produced by explosive carbon burning process. When heavier elements
notably Sr, Y, Zr, Ba etc require neutron capture on slow time scale, by iron
group nucleotide already present in the star. A peculiar type of star 73 DRA
has been investigated for many a time. It is full of chromium with europium and
strontium. The star showed the presence of Cr, Eu, Sr and also Mn, Fe, Ni, in
gaseous form while osmium (z=76) is present in both neutral and ionized form.
The importance of these heavy elements is that, some of them such as Iridium,
gold, uranium are also produced in the stars in the gamma process of nucleus
synthesis [Neutron capture slow process]
So Helium, L atoms, Carbon, Iron, gold,
chromium, nickel, silicon and many other elements are built up in the stellar
interior. Although the net fusing of hydrogen into helium dominates however at
this stage. Helium builds up in the core. The supply of hydrogen fuel
diminishes and eventually becomes in sufficient to provide energy to hold up
the strain position. As the energy production decreases, the core of the
star contracts and heats up through release of gravitational energy. With a
hotter center there is a greater outward pressure and the outer layer of the
star expands, so that the star now becomes a RED
GIANT. The red giant has a radius hundred times that of a sun. Mean
while in the hotter core a new series of fusion reactions begins and with the
helium as the fuel many elements like carbon oxygen, neon, magnesium. When
helium will exhaust as a fuel, the carbon burning process will start as 12C as
a fuel in the star. In any star the internal temperature and density and
therefore the rate at which the energy is generated depend sensitively on the
opacity of the stellar material or in other words, on the ease with which the
photons can escape from the stellar core. In simple terms you can say greater
the opacity harder it is for heat to get out making core hotter. Opacities in
normal star can be calculated reliably from knowledge for the abundance of the
constituent elements and their ionization site
Suernova-: Another
important thing in our universe are the supernovas or novas. The supernovas are
the explosion of the central core or outer core of a giant massive star. These
supernovas are found in the binary star system. A star may end its life cycle
either in the form of a RED GIANT or
in the form of a white dwarf or in
the form of a “ black Dwarf” or in the form of “ neutron Star” or in Black
Hole” or in the form of Supernova Explosion”.
When the explosion of a star occurs in
small scale, we call it Nova. In Big bang concept, apart from hydrogen, a
little helium was produced. Every atom of every element had been built up by
the nuclear fusion reaction in the stellar pressure cooker. The elements only
could arrive in the interstellar space
to mingle in the clouds of forming protostars is through this supernovas Novas are however quite different from
supernovas. Novas occur in binary star system and are powered by silicon or
carbon fusion. Supernovas occur in
single associated with old population II
stellar system such as elliptic galaxies and in globular clusters. The
classical supernovas are therefore a subset of the cataclysmic variable class
of objects, which undergoes out bursts with peak luminosity ~ 5x1037
to 5x 1038 ergs S-1 in every 104 to 105
years. Around 10-5 to 10-4 MO material are ejected at velocity
typically 1000 Kms-1 at each outburst of supernova. The central
system is a semi detached binary stars, containing a white dwarf . Classical
supernova out burst was observed in 1901, where as dwarf nova out burst was
first observed in 1986.
Supernovas
are two types Type-1(SN-I) and Type 2(SN_II) supernovas. Most astronomers agree that a type 1a
supernova starts with a white dwarf — an aging star that crams as much mass as
the sun into a volume no bigger than Earth. Most white dwarfs are cold and inert.
But if the star has a companion, it will siphon mass off the neighbor star
until tipping the scales at about 1.4 solar masses. At that mass, the white
dwarf becomes dense and hot enough to initiate an explosion. Mass accreting
white dwarfs, in close binary system of stars are Type-1 supernovas, while low mass (M70t <5MO) binary X ray sources
are known as Type II supernovas. Supernovas are the brightest source of
IRAS and radio noises. Supernovas are the sources of Cosmic rays also .The bulk
of the cosmic rays with high intensity are local cosmic rays and they are derived
from many such supernovas in past
distributed through our galactic disks. Historical supernovas are all too recent
and too distant , to be significant contributor of cosmic rays. In 6th April of 1947 ( almost 9 years before I was
born in this planet) a supernova, in a satellite of famous Whirlpool galaxy
called MSI was observed . A star in that galaxy
had a sudden maximum Brightness and following that within a few weeks it faded out
and had been then overlooked. A supernova appears in the spiral
galaxy on an average once in 400 years approximately. The most distant
supernova so far detected is 10 billion light years away from our earth, the first generation star it was. How much my father was correct, I often think
it today
The
remnants of the Exploding stars or supernovas are called Supernova remnants.
They are easily identified by radio astronomers up to millions years after
their explosion. The optical ultra violets and X-rays continue are produced
by the supernova explosion and interaction of the resting debris (Supernova
remnants), with dense Circumstellar gas shell, previously formed by the stellar
wind of the progenitor supernova. L. Stavely Smith , in 1992 showed the
birth of the radio noise supernova remnants SNR1987A, following radio outbursts
of Supernova 1987A[ Nature Vol-355 1992]. In the mid 1990, about 1200
earthen days after the supernova radio emission was detected at frequencies 843
MHZ and 8.6 GHG and this radio emission was within 0.5 arsc of the optical
supernovas
Although both young and old star can give rise to
supernovas, the massive stars, none of which is thought to live more than
several million years, are also thought to end their life in this way. Supernovas
can occur in conjunction with their satellite planet or binary stars. One of
You among readers of our thesis may obviously ask me that in what conditions
could a star or a planet can survive such a nearby explosion? Several
simplifying assumption can be made to answer this question.
1) The time of mass ejection will be small compared with the orbiting
period
2) The mass
of the second star or planet will be smaller than that of the pre- supernova
star. The first simplification was based on that the
ejection velocity of major fraction of the matter from a supernova will be
comparable with or larger than its initial escape velocity from the pre-
supernova star. Because the binary number is necessarily at larger radius, its
orbital velocity will be less than the average ejection velocity. If the
combined mass is reduced to less than a half by the supernova, in the limit,
where the mass ejection is sudden and where the mass of the secondary is small,
the system will un-banned regardless of the effects of the collision of the
ejected matter within the satellite of the planet.
The fractional mass ejection by supernova is
known for the thermonuclear supernova model. No remnant of star remain on the
other hand models of neutron star supernova, predicts various fractional mass
ejection depending on mass and structure of the initial star. But all the
models, be it thermonuclear or neutron star or cataclysmic variables predicts a
small fractional mass ejection, for the models slightly more massive mass than
C.S. Limit, and are self consistent, in that the mass of the remnant neutron
star does not exceed current stability limit. A star of initial mass 1.5MO leaves a remnant neutron star of mass 1MO.
The link between supernova explosion and formation of a neutron star has to be
rather established even if Type II supernovas are expected to leave to a
stellar component. Only five example of Pulsar
Supernova remnant association are known on our galaxy and in large
Megallenic cloud.
Previously as we the authors told, that mass
accreting white dwarf in close binary system can be considered to be Type-1
supernovas progenitors. Low mass (Mtot≈5MO) binary X ray sources( Known as type
II supernovas) appear to be descendents of cataclysmic variables and thus they
have been produced by collapse of a mass
accreting white dwarf. The fashionable model of explaining the out burst
involves central deflagration of a white dwarf in close binary system living no
remnant. But this model implies a unique configuration and do allow for
variation. Slow supernovas show higher peak of luminosity, higher velocity in
their ejecta and slower decline in their light curve. Fast Supernovas are
dimmer velocities of expanding material are low and light curve decay is
faster.
Super
hemps_: They are periodic increase in Brightness (up to 40%) that are
observed during occasional super out bursts lasting about 12 days, that are
additional to normal outbursts of a subclass of white dwarf Nova. Dwarf Nova’s
are characterized by two distinct class of out bursts. Normal outbursts of duration ~2 days and less
frequent super outbursts which lasts for ~12 days. During super outbursts,
super hemps are observed which modulate the visible light by≤40% with a period
3-7% longer than biniary period.
What is the Mechanism of
Explosion in Supernova
Mechanism
of Explosion in Supernova-a mechanism proposed by Professor Pranab Kumar
Bhattacharya Mr, Rupak Bhattacharya_: How much correct it is?-
What is the mechanism of a supernova
explosion in a star? It is not known yet and yet explained very well.
Possibly
one of the standard mechanisms of a supernova is the collapse& out
going shock due to collapse, leaving behind a neutron star, is the collapse of
the iron core of a massive star. During the initial
phase of the collapse, a sizable portion of the star transfers into neutrinos
with emissions of ve energy≤10Mev.[Rupak
Bhattacharya and Professor Pranab Kumar Bhattacharya’s theory] The
collapse phase lasts until the infiltrating matter becomes opaque to neutrinos.
A few~1056 ve neutrinos
are emitted during this phase. As the collapsed core reaches nuclear matter
densities, an out going shock develop. When the shock reaches the dense layer
that are still transparent to neutrinos, another ~1056V mostly Ve are expected to be emitted. The second one
of the bursts , produce neutrinos with an average energy~10Mev5~10. The whole process
lasts much less than a second. The remainder of the gravitational energy (~2x1053ergs) is emitted in the
form of vv pairs of all flavors. Although the neutron star contain vv pairs of
very high energy (100Mev), the only low energy one is eliminated, because the
neutrinos mean the free path, is strongly energy dependent. The energy is
larger for µ, e R neutrinos (Rupak neutrinos 115<Mh<127 GeV). There are dozen of neutrinos
particles of 7-35 mev mass in that energy. There charges is smaller than about
10-17 times the charge of
electron. [Such a neutrinos is R particles or R neutrinos-a near zero mass 115<Mh<127 GeV, conceptualized by Rupak Bhattacharya
as Rb+ Rb- and hence nomenclatured here according
to his name]
What is the Key thermonuclear feature of an
expanding star that will end it in supernovas? The ignition of helium in
the hydrogen as soon as exhausted, in core of a low mass star, in the presence
of a degenerate electron gas which is providing the bulk of the pressure
support of the star, the expansion of the star core starts. Because pressure of
such a gas does not increase ,substantially when temperature rises, where as
the rates of thermonuclear reaction increase dramatically with increasing
temperature, a brief run away in thermonuclear activity ensues. After this the
star in there core quickly expands. After only a small degree of nuclear
burning to an adjusted configuration, where burning can proceed in hydrostatic
equilibrium with subsequent discovery of very effective cooling of stellar
interior due to neutrinos emission, it has become apparent that intrinsically
more explosive nuclear fuel namely 12C
and16O may also ignite in
a very degenerate electron gas and that in that case, the run away in nuclear
reaction may be great enough completely to disrupt the star via a thermonuclear
explosion. The high temperature of the explosion which lasts only a fraction
of second produces such a high degree nuclear processing that expelled
thermonuclear product are vastly different than the composition of the mass
zone of the star, before the explosion. The key thermonuclear feature of
explosive burning is that several fuel combust at temperature considerably
higher than those at which same fuel burn in an object in hydrostatic
equilibrium with considerable effect in abundances of ejected matter. The over
heating may result either from the fact that the fuels first ignite in a
degenerate electron gas for the non central mass zones from the compression
heating, produced as a strong pressure and have propagation outward fro an
expanding core. In either case large amount of thermal energy are liberated in
a time short compared with star’s ability to compensate hydro dynamically, with
the result that the entire star may be given with positive energy sufficient to
disrupt it in explosion.
Before
the explosion, the gas is virtually half and consisted of 12C and 16O.
The first indication of importance of dynamics of the explosion of the final
nuclear product came in a study of carbon burning phenomenon of Arnet, who
established a numerical scheme for solving the nuclear reaction net work that
result when12C nuclear reaction began to undergo the fusion reaction
in the interior of the star before supernova[ Arnet W.D & Truran J.W
Astrophysics Jpurnal V157;P339;1969]
12C+12C 23Na+P+2.238mev 23Mg+tn -2.623mev 20 Net+α+4.616Mev
A
large numbers of computed reactions are thus possible, as the fusion reaction liberated proton, neutron,
neutrinos and alpha particles and began to react with all of the nuclear
species generated within the gas. Before the explosion, the gas is virtually
half and half of the 12C and 16O as produced in previous
epoch on helium burning plus 2% of 18O which is the result of
earlier conversion, within the same star, of all of the original CNO nuclei in
to 18O by hydrogen burning and helium burning in turn. Carbon burn
furiously for about 1/10th of
second at which time reactions are frozen by falling temperature, associated
with vigorous expansion of gas. Most of the carbon and virtually all of the
initial oxygen remain unburned, so that the final ratio of 12C/24Mg
matches the solar ratio. More subsequently the nuclei 2One,23Na, 24Mg,
26Mg,27Al, 29Si and 3O and some
time 31P are produced. So today whatever elementary nuclei we know in our earth or in earth’s atmosphere
is the fusion-burning product of a supernova explosion in a dying star.
1987
A Supernova-: and Recently detected
Supernovas[ Picture by Geoff
Brumfiel on July 09, 2009 at The Great Beyond, Nature.com]
In
our galaxy there were evidences of eight supernovas. They are in the years
185,393,1006 AD and in 1054,1181,1572,1604,and very recently one is 1987.Only
supernovas 1006,1572,1604 were observed by European Astronomers. The
supernova of 1054 was as a cloudy patch, and remains still as Crab nebulae as
the legs of a crab. It is the remnant of that supernova. It is at a
distance of 4500 light years away and is left over gases that has a diameter of
about 6 miles. [Mitra A.K- Space Light first year 2nd
quarter1997 P10]. Supernova 1987A occurred in the large Megaloionic Cloud
(MLC).It was a supernova of a giant star SK69202 that exploded. The star was
the star of multiple star systems instead of a binary star system. SN 1987a was 18 solar mass blue giant Sanduleak
-69° 202a, a mere 0.000168 billion light-years distant. This star
had lost a considerable mass of M20O due to the explosion. The other
members of this giant multiple system is now visible as supernova remnant. The
SK 69202 was probably a red super giant 104—105 years ago.
The outer envelop, blue star giant progenitor star is preserved during the
rapid supersonic un turbulence outflow of the supernova. The huge amount of R-
neutrinos (Rupak Particles) are now emitted by this 1987A supernova proposes
the formation of a neutron star, inside this supernova some have reported
that central region of this supernova was a central pulsar. However the
history of this supernova 1987A is today 23 years old. In the supernova 1987A
there is evidence of presence of H3+ in the envelope or in the shell
of it. The infrared L window spectrum of supernova 1987A is between 2.95-4.15um
were obtained by hydrogen re combination line ( Mcikle.W. PS Not.R. Astr
Society V283;P193-223;1989). But from 110 days onward there were an
evidence of hydrogen recombination line between spectrum 3.41-3.53um. These
were possibilities in wave length at which H3+ announces most strongly presence
of a planet like Jupiter (Okata.T etal- Astrophysics J-Vol351;P253-56;1990).When
the first explosion of supernova 1987A happened there were a brief initial
outburst of radio emissions that lasted for more than a few days. The expanding
Nebulae were set into motion by the ejection and cooling of ejected material
and its interaction with circumstellar material that surrounded the
progenitor& was then non visible at the available radio frequencies.
Evolution of radio-supernova remnant over the last years provided us the
information about the progress of the expanding supernova remnant. The nature
of its unusual progenitor star which was first a red
giant and then a blue giant, before it exploded. In the red giant phase, the
star threw off a dense slow moving wind which was succeeded by a more tenuous
but faster wind from the blue giant. The circumstellar material of the
progenitor at the moment of the explosion there fore consisted of a hot thin
gas- cocooned inside a cooler thicker shell with a supersonic shock wave
created at the boundary, as the blue giant
wind ran into red giant wind. The first brief flash of radio emission was a
very minor part of the initial supernova outbursts and was probably
attributable to the propagation of shock wave from explosion through the thin
material immediately surrounding what had been progenitor star.
Supernova are now routinely observed in other
galaxies . During the life time of a galaxy about 10 billion years, a hundred
millions of stars exploded. Amongst them, David Helfend and Knoxlong reported
an extremely intense burst of hard X-ray and gamma rays which was also recorded
by nine interplanetary space crafts and which was also probably Supernova N49
remnant in large Megellanic Cloud [ MLC is a small satellite galaxy of Milky
Way 18,0000 light year distant)[ Nature march5,1979 & decemb6 1979]. The
recent nova which had been detected in Cygx-1 galaxy. It was Nova V404 cygni-
Low mass x ray binary emits x ray and x ray behavior is similar to black hole
system. In April 6,1947 discovered a supernova in a satellite of famous
whirlpool galaxy M51- A star suddenly had maximum brightness and had then
overlooked. On 9th January 2008, while viewing of galaxy NGC 2770 an unexpected
transient burst of Xray was detected in one of the galaxies spiral arm. Further
observation showed that the burst was a first sighting of new type of Ibc
supernova duly was named as SN200D. Most distant Supernovae are super bright, and that makes them easy to
see from far away. Very far away. 11 Billion Light years to be exact from
earth. almost at time of birth of first generation stars and galaxy.
Pulsar formation is generally attributed to
supernova events and two pulsars are till associated with known supernova
events. They are Crab Nebulae pulsar NP0532 and Vela. Other pulsars are close
enough to supernova remnants to suggest an association but only if they are
moving away from the remnants at velocities of order 103 Km/second.
Fowler KA and Hogel F in 1963 suggested that supernova core may well be too
massive to form a gravitationally stable
object(neutron Star) and gravitationally Collapsing Object(black Hole too).
They suggested that systemic ejection of Radio luminous material from galaxy
could be caused by symmetrical process occurring in the collapse of very
massive objects, thus the more massive core could fission into several less
massive objects. The same process can be applied to supernova events where core
fragments into some distribution of neutron stars” Black holes’ and general
debris[ Fowler WA, Hoyel F Nature 197; 533;1963]. There is a pulsar PSR 1509-58
located near the center of radio supernova remnant MSH 15-52, a supernova
remnant of supernova AD1054. This pulsar is young only about 1700 years. The
near coincidence of this age with that of supernova of AD 185 strongly suggest
that PSR1509-58 was born in AD1054 supernova explosion.
Why Supernovae? – the new measure of the Universe When Einstein got rid of the cosmological
constant and surrendered to the idea of a non-static Universe, he related the
geometrical shape of the Universe to its fate. Is it open or closed, or is it
something in between – a flat Universe? An open Universe is one where the
gravitational force of matter is not large enough to prevent the expansion of
the Universe. All matter is then diluted in an ever larger, ever colder and
ever emptier space. In a closed Universe, on the other hand, the gravitational
force is strong enough to halt and even reverse the expansion. So the Universe
eventually would stop expanding and fall back together in a hot and violent
ending, a Big Crunch.
Most cosmologists, and I myself however, would prefer to live in the
most simple and mathematically elegant Universe: a flat one, where the
expansion is believed to decline. The Universe would thus end neither in fire
nor in ice. But there is no choice left by laws of the Universe. If there is a
cosmological constant, the expansion will continue to accelerate, even if the
Universe is flat.2011 Physics Nobel Laureates expected to measure the cosmic
deceleration, or how the expansion of the Universe is slowing. Their method
was in principle the same as the one used by astronomers more than six decades
earlier: to locate distant stars and to measure how they move. However, that is
easier said than done. Since Henrietta Leavitt’s days many other Cepheids have
been found that are even farther away. But at the distances that astronomers
need to see, billions of light years away, Cepheids are no longer visible. The
cosmic yardstick needed to be extended. Supernovae
– star explosions – became the new standard candles. More sophisticated
telescopes on the ground and in space, as well as more powerful computers,
opened the possibility in the 1990s to add more pieces to the cosmological
puzzle. Crucial were the light-sensitive digital imaging sensors –
charged-coupled devices or CCD – the invention by Willard
Boyle and George Smith who were
awarded Nobel Prize in Physics in 2009. White dwarfs exploding
the newest tool in the astronomer’s toolbox is a special kind of
star explosion, the type Ia
supernova. During a few weeks, a single such supernova can emit as
much light as an entire galaxy. This type of supernova is the explosion of an
extremely compact old star that is as heavy as the Sun but as small as the
Earth – a white dwarf. The explosion is the final step in the white
dwarf’s life cycle. White dwarfs form when a star has no more energy at its
core, as all hydrogen and helium have been burned in nuclear reactions. Only
carbon and oxygen remain. In the same way, far off in the future, our Sun will fade and cool down as it reaches its end as a white
dwarf. A far more
exciting end awaits a white dwarf that is part of a
binary star system, which is fairly common. In this case, the white dwarf’s strong gravity robs the
companion star of its gas. However, when the white dwarf has grown to 1.4 solar
masses, it no longer
The nuclear fusion products emit strong radiation that increases rapidly during
the first weeks after the explosion, only to decrease over the following
months. So there is a rush to find supernovae – their violent explosions are
brief. Across the visible Universe, about ten type Ia supernovae occur every
minute. But the Universe is huge. In a typical galaxy only one or two supernova
explosions occur in a thousand years. In September 2011, we were lucky to
observe one such supernova in a galaxy close to the Big Dipper, visible just
through a pair of regular binoculars. But most supernovae are much farther away
and thus dimmer. So where and when would you look in the canopy of the sky? manages to hold together. When this
happens, the interior of the dwarf becomes sufficiently hot for runaway fusion
reactions to start, and the star gets ripped apart in seconds.
From the planet the earth here towards eternity?
So what is it that is speeding
up the Universe? It is called dark energy and is still probably a
challenge for particle physics, a riddle, that no one has managed to solve yet
of what it is composed of. Several ideas have been however proposed.
Within the framework
of the standard cosmological model, the acceleration is generally believed to
be caused by the vacuum energy (sometimes called ”dark energy”) which – based
on concordant data from the S Ne, the observations of the anisotropies in the
CMB and surveys of the clustering of galaxies – accounts for about 73% of the
total energy density of the Universe. Of the remainder, about 23% is due to an
unknown form of matter (called ”dark matter”).
Only about 4% of the energy density corresponds to ordinary matter like
atoms in everyday life, the
effects of the vacuum energy are tiny but measurable – observed for instance in
the form of shifts of the energy levels
of the hydrogen atom, the Lamb shift. The evolution of the Universe is
described by Einstein’s theory of general relativity. In relativistic field
theories, the vacuum energy contribution is given by an expression
mathematically similar to the famous cosmological constant in Einstein’s theory. Our question is so question of whether the vacuum energy term is truly time independent
like the cosmological constant, or varies with time,.
The simplest is to
reintroduce Einstein’s cosmological constant, which he once rejected. At that
time, he inserted the cosmological constant as an anti-gravitational force to
counter the gravitational force of matter and thus create a static Universe.
Today, the cosmological constant instead appears to make the expansion of the
Universe to accelerate. The cosmological constant is, of course, constant, and
as such does not change over time. So dark
energy becomes dominant when matter, and thus its gravity, gets diluted due to
expansion of the Universe over billions of years. According to scientists, that
would account for why the cosmological constant entered the scene so late in
the history of the Universe, only five to six billion years ago. At about that
time, the gravitational force of matter had weakened enough in relation to the
cosmological constant. Until then, the expansion of the Universe had been
decelerating.
The cosmological constant could have its
source in the vacuum, empty space that, according to quantum physics, is never
completely empty. Instead, the
vacuum is a bubbling quantum soup where virtual particles of matter and
antimatter pop in and out of existence and give rise to energy. However,
the simplest estimation for the amount of dark energy does not correspond at
all to the amount that has been measured in space, which is about 10120
times
larger (1 followed by 120 zeros). This constitutes a gigantic and still unexplained
gap between theory and observation – on all the sea beaches of the world there
are no more than 1020 (1 followed by
20 zeros) grains of sand. It may be that the dark energy is not constant after
all. Perhaps it changes over time. Perhaps an unknown force field only
occasionally generates dark energy. In physics there are many such force fields
that collectively go by the name quintessence, after the Greek name for
the fifth element. Quintessence could speed up the Universe, but only
sometimes. That would make it impossible to foresee the fate of the Universe.
Whatever dark energy is, it seems to be here to stay. It fits very well in the
cosmological puzzle that physicists and astronomers have been working on for a
long time. According to current consensus, about three quarters of the Universe
consist of dark energy. The rest is matter. But the regular matter, the stuff
that galaxies, stars, humans and flowers are made of, is only five percent of
the Universe. The remaining matter is called dark matter and is so far
hidden from us. The dark matter is yet another mystery in our largely unknown
cosmos. Like dark energy, dark matter is invisible. So we know both only by
their effects – one is pushing, the other one is pulling. They only have the
adjective “dark” in common.[2]
The study of distant
supernovae according to us authors may constitutes a crucial contribution to
cosmology. Together with galaxy clustering and the CMB anisotropy measurements, it allows precise determination of
cosmological parameters. The observations present us with a challenge, however:
What is the source of the dark
energy that drives the accelerating
expansion of the Universe? Or is our understanding of gravity as described by
general relativity insufficient? Or was
Einstein’s “mistake” of introducing
the cosmological constant one more stroke of his genius? Many new
experimental efforts are underway to help shed light on these questions.
So Our Questions to readers of my blogs
1] Universe has been
expanding; like raisins in a raisin cake swelling in the oven, But No body
still answered what is beyond that Planck’s moment of Big Bang Creation of our
universe. Was there another universe? Was there multiple Universe? Or Multi
electrical universe?—
2] Question
Yet remains to us how these supernovas explode? What is the
mechanism behind it? No physics probably
answered it yet. Here may be some explanations by my brothers Rupak
Bhattacharya and Ritwik Bhattacharya the
authors— Our Question No –(2)
What is the
Mechanism of Explosion in Supernova
( our Question NO-3)
Mechanism of Explosion in Supernova-a
mechanism proposed by Professor Pranab Kumar Bhattacharya Mr, Rupak Bhattacharya_: How much correct it is
3] So what is it that is speeding up the Universe? It is called dark energy and is still a challenge
for physics, a riddle, that no one has managed to solve yet of what it is
composed of
4] . Our question is question of whether the vacuum energy term is truly time
independent like the cosmological constant, or varies with time,.
Do you know the answer? If yes please contact
References
1]”
Did our universe started in a Big Bang gospel or Just Be?” Authors: Professor
Pranab Kumar Bhattacharya, Mr. Rupak Bhattacharya, Mr. Ritwik Bhattacharya Mrs. Dalia Mukherjee & Miss Upasana
Bhattacharya in the chapter” Fate of a Star” once published at www.unipathos.com as E book in July 2004.
The Website www.unipathos.com had been surrendered to star Dust Company in
2010 and the same E book No more available there.
2]
“Written in the stars”: THE NOBEL
PRIZE IN PHYSICS 2011
INFORMATION FOR THE PUBLIC
published in www.nobelprize.org
By Science Editors Lars Bergström, Olga Botner, Lars Brink, Börje Johansson, The
Nobel Committee for Physics/The Royal
Swedish Academy of SciencesEditor: Annika Moberg The Royal
Swedish Academy of Sciences THE NOBEL PRIZE IN PHYSICS
2011 THE ROYAL SWEDISH ACADEMY
OF SCIENCES HTTP://KVA.SE
Links
to see other sites?
1] Runaway
Universe, www.pbs.org/wgbh/nova/universe/
2] Appell,
D. (2008) Dark Forces at Work, Scientific American,
Acknowledgement
& Tribute -
To our diseased parent late Mr. Bholanath Bhattacharya B.com(Calcutta Univ)
FCA(Ind.) SAS and late Mrs Bani
Bhattacharya of residence 7/51 Purbapalli, Po-Sodepur, Dist 24 parganas (north)
, Kolkata-110,WestBengal, India, for
their initial teaching for us about the
Universe, Big Bang and eternity
Copy
Right Deceleration - Copy Right of The article” Fate of a Star as
supernovas and mechanism of explosion of supernovas”
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RDF copy right rules of SPARC and PIP of 2012 of USA and PIP Rules 2012
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