Hello All
The Sloan Legacy Survey
http://www.sdss.org/legacy/aboutlegacy.html
Not complete, regarless does not show any evidence for BB.
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The 2dF Galaxy Redshift Survey
http://www.roe.ac.uk/~jap/2df/
The 2dF Galaxy Redshift Survey: Power-spectrum analysis of the final dataset and cosmological implications
I cannot see any evidence for the BBT
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Ned Wright's Cosmology Tutorial
http://www.astro.ucla.edu/~wright/cosmoall.htm
The conformal space-time diagram above shows the phi(x) at recombination determined by COBE's dT data, and the worldlines of galaxies which are perturbed by the gravitational forces produced by the gradient of the potential. Matter flows "downhill" away from peaks of the potential (red spots on the COBE map), producing voids in the current distribution of galaxies, while valleys in the potential (blue spots) are where the clusters of galaxies form
This link also does not prove the BBT.
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Evolution since z = 0.5 of the Morphology-Density relation for Clusters of Galaxies
http://arxiv.org/abs/astro-ph/9707232
Using traditional morphological classifications of galaxies in 10 intermediate-redshift (z~0.5) clusters observed with WFPC-2 on the Hubble Space Telescope, we derive relations between morphology and local galaxy density similar to that found by Dressler for low-redshift clusters.
Taken collectively, the `morphology-density' relationship, M-D, for these more distant, presumably younger clusters is qualitatively similar to that found for the local sample, but a detailed comparison shows two substantial differences: (1) For the clusters in our sample, the M-D relation is strong in centrally concentrated ``regular'' clusters, those with a strong correlation of radius and surface density, but nearly absent for clusters that are less concentrated and irregular, in contrast to the situation for low redshift clusters where a strong relation has been found for both. (2) In every cluster the fraction of elliptical galaxies is as large or larger than in low-redshift clusters, but the S0 fraction is 2-3 times smaller, with a proportional increase of the spiral fraction. Straightforward, though probably not unique, interpretations of these observations are (1) morphological segregation proceeds hierarchically, affecting richer, denser groups of galaxies earlier, and (2) the formation of elliptical galaxies predates the formation of rich clusters, and occurs instead in the loose-group phase or even earlier, but S0's are generated in large numbers only after cluster virialization.
Again no evidence for the BBT
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We analyse $u-r$ colour distributions for several samples of galaxies in groups drawn from the Fourth Data Release of the Sloan Digital Sky Survey. For all luminosity ranges and environments considered the colour distributions are well described by the sum of two Gaussian functions. We find that the fraction of galaxies in the red sequence is an increasing function of group virial mass. We also study the evolution of the galaxy colour distributions at low redshift, $z\le0.18$ in the field and in groups for galaxies brighter than $M_r-5\log(h)=-20$, finding significant evidence of recent evolution in the population of galaxies in groups. The fraction of red galaxies monotonically increases with decreasing redshift, this effect implies a much stronger evolution of galaxies in groups than in the field.
again I cannot see any evidence for the BBT.
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http://arxiv.org/ftp/astro-ph/papers/0109/0109358.pdf
This new paradigm has transformed our
view of galaxy evolution. It is now
believed that most visible galaxies are
embedded in much larger and more
massive dark matter halos that detached
from the expanding cosmic plasma
(created in the Big Bang) at early times.
Furthermore, galaxies are no longer
viewed as growing in isolation, but rather
as being linked into a web of large scale
structure, which originated in the density
fluctuations traced by the surface
brightness variations now seen in the
cosmic microwave background (2-5).
Observations of galaxy morphology now
span about 70% of the total age of the
Universe and allow this paradigm to be
tested.
Caveats
Morphological classification of galaxies
at redshifts near z = 1 is challenging
because the number of pixels per image
may be as much as ~100 times smaller
than in the images of nearby galaxies.
Classification at z ~ 1 therefore
represents a considerable extrapolation
from similar work at z ~ 0. Caution has to
be exercised to avoid resolutiondependent
effects that might affect
images of distant galaxies more than they
do nearer galaxies. The slight “under
sampling” of images on HST’s Wide-
Field/Planetary Camera 2 makes the
classification of very compact galaxies
(such as distant ellipticals) particularly
difficult. Another problem is that it is
often tempting to “shoehorn” slightly
peculiar distant galaxies into the familiar
Again no evidence for the BBT.
But it does indicate that cluster formations are more so than not. I would expect roaming of some stars and glaxies. The extent is another question. They will still form part of the super dupper cluster.
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http://hubblesite.org/newscenter/archiv ... 10/video/b
NASA's Hubble Space Telescope has found the oldest burned-out stars in our Milky Way Galaxy. These extremely dim and old "clockwork stars" provide a completely independent reading of the age of the universe. By measuring the temperature of white dwarf stars in a globular star cluster, astronomers can estimate their ages. Hubble's sensitive detectors came up with an age of 12 to 13 billion years, dovetailing nicely with other independent measurements placing the universe's age at 13 to 14 billion years.
If you consider this as evidence for the age of the universe, this is rape of science.
Some of the stars are 12 to 13 Gyrs old (This depends on how they are dated). Imagine how long to form our MilkyWay with the dozens of mini galaxies around it. Without any calculations I would say over 50 Gyrs. I hope one day someone does a proper claculation. I know BB people will add ad hoc ideas and make it 13.7Gyrs.
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http://arxiv.org/abs/astro-ph/0501088
THE ASSEMBLY OF DIVERSITY IN THE MORPHOLOGIES AND STELLAR POPULATIONS
OF HIGH–REDSHIFT GALAXIES1
http://arxiv.org/PS_cache/astro-ph/pdf/0501/0501088.pdf
Reading through this paper
CONCLUSIONS
We have studied the evolution in the morphologies and colors
of two samples of high–redshift galaxies at z ∼ 2.3 and
z ∼ 1 in order to investigate how these galaxies assembled
their stellar populations. From z ∼ 2.3 to 1, galaxies grow
in size, stellar mass, total color, and internal color dispersion,
which we interpret as evidence for an increase in the diversity
of stellar populations as galaxies assemble.
The majority of luminous galaxies (M(B) ≤ -20.5 in the
rest frame) in the z ∼ 1 sample have rest–frame optical morphologies
that are classifiable as early–to–mid Hubble types.
These galaxies have regular, symmetric morphologies, and
many show strong transformations between their morphologies
when viewed at rest–frame UV and optical wavelengths.
In contrast, the rest–frame optical morphologies of the luminous
(M(B) ≤ 20.5 in the rest–frame) galaxies at z ∼ 2.3
are irregular and/or compact, and there is little difference in
the galaxy morphologies from rest–frame far–UV to optical
wavelengths. None of the z ∼ 2.3 galaxies appear to be normal
Hubble–sequence galaxies. Because the z ∼ 2.3 galaxies
show little transformation in morphology fromrest–frameUV
to optical wavelengths, the UV components are not generally
the small, star–forming pieces within larger host galaxies.
Themean galaxy size increases fromz∼2.3 to 1 by roughly
40%, in broad agreement with expectations from hierarchical
models. Furthermore, the number density of large galaxies,
r1/2 > 3 kpc and M(B) ≤ -20, increases by a factor of
≈ 7. We have tested that the size evolution is robust against
surface–brightness dimming effects. The half–light radii of
the z ∼ 1 galaxies when simulated at z = 2.7 decrease by
< 20% compared to their measured values at z ∼ 1, but this
decrease is small compared to the observed evolution. The
radius–luminosity distribution of galaxies at z ∼ 1 is consistent
with the local distribution for pure luminosity evolution.
However, the size–luminosity, and size–mass distributions of
z ∼ 2.3 galaxies indicate that they are not the fully formed
progenitors of large, present–day galaxies. Galaxies at z & 2
must continue to build, both in terms of size and stellar mass.
We have analyzed the rest–frame UV–optical total colors,
and the internal color dispersion using the novel statistic developed
in P03. The internal color dispersion quantifies differences
in galaxy morphology as a function of wavelength,
and between rest–frame UV and optical wavelengths it constrains
the amount of current star–formation relative to the
older stellar populations. Both the mean and scatter of total
color and the internal color dispersion increase from z ∼ 2.3
to 1. At z ∼ 1, galaxies with high internal color span a range
of morphological types. Many are spiral galaxies, with a few
starbursting and interacting systems. There is no clear correlation
between total color and the internal color dispersion,
although galaxies with the highest internal color dispersion
have moderate total UV–optical colors, which implies a mix
of heterogeneous stellar populations. The z ∼ 1 galaxies with
the highest internal color dispersion appear to be early–to–
mid-type spiral galaxies, and they exhibit strong transformations
between their UV and optical rest–frame morphologies.
At z ∼ 2.3 few galaxies have high internal color dispersion,
and those that do also have interacting and disturbed morphologies,
which implies that the UV–optical light from these
galaxies is dominated by young, largely homogeneous stellar
populations. We interpret the evolution in galaxy color and
internal color dispersion as evidence that the diversity in the
stellar populations of galaxies is increasing from z ∼ 2.3 to 1
as the older stellar components build up over time.
To interpret the evolution in the properties of galaxies, we
have modeled the stellar populations of galaxies in spheroidal
and disk components, and star–forming H II regions. These
simple models broadly support the conclusion that the range
of internal color dispersion corresponds to increased diversity
in the galaxies’ stellar populations. Galaxies with significant
bulge components with star–forming disks and/or compact,
H II regions produce high internal color dispersion, and
broadly reproduce the colors, sizes, and internal color dispersion
of the high–redshift galaxies. We find that large values
of the internal color dispersion require galaxy to have formed
spatially segregated, diverse stellar populations where old
stars dominate the optical light and stellar mass (i.e., & 80%
of the stellar mass resides in stars > 1 Gyr). For smaller fractions
of old stars, young stellar populations dominate the UV–
optical internal colors.
The scatter in the internal color dispersion of the z ∼ 2.3
galaxies is smaller than what is allowed under these models
and basic timescale arguments. We interpret this as evidence
that brief, discrete and recurrent starburst episodes dominate
the star–formation history of galaxies at this epoch. If these
arise from strong interactions or mergers of gas–rich conDIVERSITY
IN THE STELLAR–POPULATIONS OF GALAXIES 19
stituents, then they will erase any heterogeneity in the stellar
content that otherwise develops, and this is supported by
the low internal color dispersion observed in galaxies at this
epoch. The greater range of internal color dispersion that
forms at z ∼ 1 suggests that major mergers are less frequent
and more quiescent star–formation mechanisms are the norm.
The greater diversity in the stellar populations of these
high–redshift galaxies coincides with the emergence with
large Hubble sequence galaxies. Large values of the UV–
optical internal color dispersion require a diverse and spatially
unmixed stellar population, and this occurs when galaxies
have formed most of their stellar mass. In order to maintain
the spatial heterogeneity between the young and old stellar
populations also requires that major mergers are less common
at this epoch. These conditions all occur at z.1.4, which naturally
allows galaxieswith Hubble–sequencemorphologies to
develop.
We wish to thank our colleagues for stimulating conversations,
the other members of the HDF–N NICMOS GO team
who contributed to many aspects of this program, and the
STScI staff for their optimal planning of the observations and
efficient processing of the data. We are grateful to Tamás Budavári
for helpful assistance and for providing the photometric
redshifts, and to Eric Bell and George Rieke for their comments
on this manuscript and many interesting discussions.
We thank the anonymous referee for insightful and prompt
comments, which improved the quality and clarity of the conclusions
in this paper. We also wish to acknowledge the very
generous hospitality and science–conducive environment of
the Aspen Center for Physics, where much of this work was
finished. CP also thanks STScI for hospitality on several visits
while this research was completed. Partial support for this
work was provided by NASA through grant GO-07817.01-
96A from the Space Telescope Science Institute, which is operated
by the Association of University for Research in Astronomy,
Inc., under NASA contract NAS5-26555. CP acknowledges
partial support by NASA through Contract Number
960785 issued by JPL/Caltech.
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The links above do not prove to me that the BBT did happen.
They do show, that many think along the lines of the BBT and in so doing make assumptiions. I worry that, because of these assumptions the so called evidence is also missleading.
The other worry is that the redshift used to measure distance could be disputed.
Is it better to agree with the BB people and relax.