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Beyond IDCS J1426.5+3508



 
 
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  #11  
Old July 1st 12, 08:54 AM posted to sci.astro.research
Phillip Helbig---undress to reply
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Posts: 629
Default Beyond IDCS J1426.5+3508

In article , jacob navia
writes:

Note that
paradigm changes are painful but I hope people proposing a new one
won't have the problems of Galileo...


A man does not attain the status of Galileo merely because he is persecuted;
he must also be right.

---Stephen Jay Gould

1) We have a really MASSIVE cluster at 10 GY from here (3.7 from
the supposed "bang").


Right.

Note that the lensing confirms the big mass
of that cluster.


Right.

How can such a monster cluster evolve in just
3.7 GY? A galaxy merger takes like 1GY, and the central galaxy
must have done some to acquire its size.


You are making a common error: rejecting an entire paradigm because of
problems with details. Yes, if such details persist, then it might
indicate a real problem. However, structure formation is very difficult
to model compared with cosmological tests which lead to the currently
accepted "standard model".

The center of the arc
is the central cluster galaxy.


The arc is the background galaxy at higher redshift. It isn't in the
lensing cluster. Its position with respect to the lensing cluster is
also not at the center. The arc is at the edge of the cluster (as seen
on the sky). You misunderstood the abstract.

2) The lensing implies that there is a BIG galaxy much farther away,


No. It implies only that there is a galaxy farther away. (It appears
bug because of the magnification due to the lensing effect). The
question is how likely it is to have a galaxy at this redshift, not its
size.

so much farther away that it is lensed by the cluster. Then, several
questions are raised: How come that there are so many big galaxies
behind that cluster that we see a lensing effect?
Galaxies should be smaller approaching the supposed "bang"! But no,
there are so many big ones that we see a lensed one.


Again, I think you misunderstand. The lensing effect magnifies the size
of the galaxy (and, since it conserves surface brightness, also makes it
brighter.)
  #12  
Old July 1st 12, 08:57 AM posted to sci.astro.research
Phillip Helbig---undress to reply
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Posts: 629
Default Posting in ASCII

In article , jacob navia
writes:

I apologize for those problems but I can't help it. I am using an Apple
Macintosh system (OS X) and the whole system is Unicode. All software
including the mail client, text editor, web browser etc is all Unicode
(16 bits chars) and there is no way for me to see which characters
aren't ASCII since I haven't any software that doesn't accept
UTF8 (not even the vi editor!)


There are various ways to represent Unicode, UTF8 etc. A common one is
to have it correspond to ASCII if the characters in question are ASCII.
So, as long as you stick to ASCII characters, your post should show up
OK.

[Mod. note: for those people who don't know the ASCII character set, a
good rule is to avoid any accented characters, any non-Roman letters,
and any 'smart quotes'. Letters A-Z and a-z, numbers and basic
punctuation only, please. This is particularly important when cutting
and pasting from a web source. I'm posting this to make other people
aware of the issue -- mjh]


If you follow Martin's advice, things should be OK. Here is the ASCII
character set:

+------------------------------------------+
| 0 1 2 3 4 5 6 7 |
+---+--------------------------------------+
| 0 | NUL DLE SP 0 @ P ` p |
| 1 | SOH DC1 ! 1 A Q a q |
| 2 | STX DC2 " 2 B R b r |
| 3 | ETX DC3 # 3 C S c s |
| 4 | EOT DC4 $ 4 D T d t |
| 5 | ENQ NAK % 5 E U e u |
| 6 | ACK SYN & 6 F V f v |
| 7 | BEL ETB ' 7 G W g w |
| 8 | BS CAN ( 8 H X h x |
| 9 | HT EM ) 9 I Y i y |
| A | LF SUB * : J Z j z |
| B | VT ESC + ; K [ k { |
| C | FF FS , L \ l | |
| D | CR GS - = M ] m } |
| E | SO RS . N ^ n ~ |
| F | SI US / ? O _ o DEL |
+---+--------------------------------------+

The numbers at the top and at the side are combined to give the
hexadecimal number of the character. Thus, the "!" character has value
21 in hex, or 33 in decimal. Values 20 through 7E should be OK, i.e.
all but the first two columns and the DEL at the lower right. So,
anything which looks like something in the 6 rightmost columns should be
OK. (The first two columns and DEL are non-printable characters.)
  #13  
Old July 1st 12, 08:58 AM posted to sci.astro.research
Phillip Helbig---undress to reply
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Posts: 629
Default Beyond IDCS J1426.5+3508

In article , jacob navia
writes:

1) A cluster of 2.6 x 10^14 M0 in 3.7 GY is nothing special.


From the observation, we can conclude that such a cluster exists.
Without further information, we can't say whether or not it is special.
The paper mentions that it is expected to be rare (which doesn't mean it
cannot exist). You seem to say "either it is nothing special, or it
cannot exist". There is another possibility: it can exist, but be
special. Do not try to conclude more than the observations give you.
(A biologist, a physicist and a mathematician were travelling on a train
in Scotland. The biologist looks out the window, sees a black sheep and
says "Sheep are black in Scotland." The physicist looks out the window
and says "Some sheep are black in Scotland." The mathematician doesn't
need to look out the window and says "There is at least one sheep in
Scotland, which is black on at least one side.")

All those
galaxies (and the massive central galaxy) merged and concentrated
in record time. It is not only galaxy formation but also cluster
formation that must be reviewed


Right.

to fit the bang.


Unjustified extrapolation. Again, you claim that problems in structure
formation calls into question the existence of the big bang. What about
another possibility: the big bang exists, but structure formation is a
bit different than what current thinking implies? Considering the
amount of other evidence for the big bang, this seems to be the most
likely alternative, especially considering the fact that there are known
problems with the details of structure formation.


2) The fact that we see a lensed galaxy implies that there is a wide
field of BIG galaxies behind that galaxy cluster.


Why BIG?

That is nothing
surprising you say. It is just that fully formed BIG galaxies
appear immediately after the supposed bang


3.7 billion years is not "immediate".

Our
galaxy formation theories are wrong, not the bang.


Wrong in detail, probably. But that's not surprising.
  #14  
Old July 1st 12, 08:59 AM posted to sci.astro.research
Phillip Helbig---undress to reply
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Posts: 629
Default Beyond IDCS J1426.5+3508

In article , Steve Willner
writes:

The two relevant preprints seems to be the ones at
http://arxiv.org/abs/1205.3788
http://arxiv.org/abs/1205.3787

In article ,
jacob navia writes:
1) A cluster of 2.6 x 10^14 M0 in 3.7 GY is nothing special.


More like 4 to 5E14 Msun at z=1.75. There shouldn't be many such
clusters in the sky, but there should be a few. If a lot more are
discovered, something is going to have to change, but it will take
more than a single object to force changes.


One needs to interpret such rare objects properly. See recent work by
Ian Harrison and Peter Coles on extreme-value statistics in cosmology:

http://telescoper.wordpress.com/2011...-the-universe/

There is a real problem, however, with the 775 nm magnitude of the
lensed source. Even with lensing, it's too bright for the population
of known z3 objects. It's going to be very interesting to see how
this plays out.


Yes. It might be improbable. However, improbable does not mean
impossible.

How probable is it that the Moon and the Sun have the same angular size?
Doesn't this low probability question the entire big-bang paradigm? :-)
  #15  
Old July 1st 12, 09:00 AM posted to sci.astro.research
Phillip Helbig---undress to reply
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Posts: 629
Default Beyond IDCS J1426.5+3508

In article , "Richard D. Saam"
writes:

How about framing the question in terms of a more defined
Supernovae Type 1a standard candle condition.

Use the distance modulus equation:

m-M = 5 log(d) - 5

then d = 10^((m-M)/5 - 1)

From Supernovae compilation
http://supernova.lbl.gov/Union/figur....1_mu_vs_z.txt

the current maximum Type 1A redshift
2003dy z = 1.34 m-M = 45.0675055813

d = 10^((m-M)/5 - 1) = 1.03E+08 parsec or 3.18E+26 cm


I haven't checked the actual numbers, but OK so far.

This is about 2.5 percent of the present universe


First, note that the distance involved is the luminosity distance.
There is little point in expressing this in terms of the

radius


of the universe.

assuming expansion from the Big Bang
at the speed of light c/H = 1.30E+28 cm


Not sure what you mean here. The speed of light is not a limiting
factor for the expansion of the universe.

If z=1.34, then the universe is 2.34 times larger now than when the
light was emitted. This is independent of the cosmological model.

So why does type 1A 2003dy standard candle redshift (z=1.34)
represent a condition within ~2.5% of the Big Bang
with its z in the thousands and probably much greater?


I do not understand this. What does the "z in the thousands" mean?
  #16  
Old July 1st 12, 11:41 AM posted to sci.astro.research
Jos Bergervoet
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Posts: 126
Default Beyond IDCS J1426.5+3508

On 7/1/2012 9:59 AM, Phillip Helbig---undress to reply wrote:
In article , Steve Willner
jacob navia writes:

...
1) A cluster of 2.6 x 10^14 M0 in 3.7 GY is nothing special.


More like 4 to 5E14 Msun at z=1.75. There shouldn't be many such
clusters in the sky, but there should be a few. If a lot more are
discovered, something is going to have to change, but it will take
more than a single object to force changes.


One needs to interpret such rare objects properly. See recent work by
Ian Harrison and Peter Coles on extreme-value statistics in cosmology:

http://telescoper.wordpress.com/2011...-the-universe/


OK, in Fig. 1 there, 4 to 5E14 Msun at this redshift seems to
be right at the expected largest mass seen. Excellent fit!

There is a real problem, however, with the 775 nm magnitude of the
lensed source. Even with lensing, it's too bright for the population
of known z3 objects. It's going to be very interesting to see how
this plays out.


Yes. It might be improbable.


Do we also have statistical expectation curves for this? Like
the one above, but for any luminous object at this higher z,
and then combined with the probability of it being lensed?
A somewhat complicated combination of probability distributions
seems to be needed here, apparently shown in Fig. 3 in the
preprint: http://arxiv.org/abs/1205.3788

The figure seems to show quite some uncertainty (the two curves
plotted are quite different) but does lead to the conclusion at
the end of the paper, that this was an improbable observation!
Do I understand correctly that everyone agrees with that?

--
Jos
  #17  
Old July 1st 12, 01:01 PM posted to sci.astro.research
Phillip Helbig---undress to reply
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Posts: 629
Default Beyond IDCS J1426.5+3508

In article , Jos Bergervoet
writes:

Do we also have statistical expectation curves for this? Like
the one above, but for any luminous object at this higher z,
and then combined with the probability of it being lensed?
A somewhat complicated combination of probability distributions
seems to be needed here, apparently shown in Fig. 3 in the
preprint: http://arxiv.org/abs/1205.3788


In order to calculate the probability, one needs to know the number of
galaxies at this redshift. However, one needs the number at the
luminosity of the UNLENSED source. So, divide the observed luminosity
of the arc by the magnification (which depends on the lens model, but
the ballpark figure should be Ok) to get the unlensed luminosity. How
well are these numbers known? (One also has to take into account that
the area is also increased by the lens effect; normally one observes the
number of objects of a certain luminosity at a certain redshift per area
of sky.)
  #18  
Old July 1st 12, 01:36 PM posted to sci.astro.research
Jos Bergervoet
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Posts: 126
Default Beyond IDCS J1426.5+3508

On 7/1/2012 2:01 PM, Phillip Helbig---undress to reply wrote:
In article , Jos Bergervoet
writes:

Do we also have statistical expectation curves for this? Like
the one above, but for any luminous object at this higher z,
and then combined with the probability of it being lensed?
A somewhat complicated combination of probability distributions
seems to be needed here, apparently shown in Fig. 3 in the
preprint: http://arxiv.org/abs/1205.3788


In order to calculate the probability, one needs to know the number of
galaxies at this redshift. However, one needs the number at the
luminosity of the UNLENSED source.


But that seems to be a much simpler question. Their reference
Coe et al. (2006) seems to be their source for it. Anyhow, if
even that kind of basic information is uncertain, there is not
much chance to reach a valid conclusion..

So, divide the observed luminosity
of the arc by the magnification (which depends on the lens model, but
the ballpark figure should be Ok) to get the unlensed luminosity. How
well are these numbers known?


Hmm.. If you don't question the lens model, and also not the
unlensed source distribution, there is no problem, is there?

(One also has to take into account that
the area is also increased by the lens effect; normally one observes the
number of objects of a certain luminosity at a certain redshift per area
of sky.)


So by magnification, the lensing cluster is looking at a very
small area, reducing the chance something is lensed. But this
I would expect to be part of the lens model, which cannot be
wrong unless GR is wrong! (I would expect that GR simply *is*
the lens model, it is surprising that this is made an issue..)

[Mod. note: the lens model includes the mass distribution of the lens
-- mjh]

--
Jos
  #19  
Old July 1st 12, 02:35 PM posted to sci.astro.research
Phillip Helbig---undress to reply
external usenet poster
 
Posts: 629
Default Beyond IDCS J1426.5+3508

In article , Jos Bergervoet
writes:

In order to calculate the probability, one needs to know the number of
galaxies at this redshift. However, one needs the number at the
luminosity of the UNLENSED source.


But that seems to be a much simpler question. Their reference
Coe et al. (2006) seems to be their source for it.


I'm not up-to-date on galaxy luminosity functions. However, a redshift
of 3 is quite large for such things, especially allowing for the fact
that the unlensed luminosity is less. However, I would have thought
that, especially at this high (for ordinary galaxies) redshift, there
would be something more recent than 2006. In any case, such numbers
will have error bars.

Hmm.. If you don't question the lens model, and also not the
unlensed source distribution, there is no problem, is there?


No, but both have error bars.

(One also has to take into account that
the area is also increased by the lens effect; normally one observes the
number of objects of a certain luminosity at a certain redshift per area
of sky.)


So by magnification, the lensing cluster is looking at a very
small area, reducing the chance something is lensed. But this
I would expect to be part of the lens model, which cannot be
wrong unless GR is wrong! (I would expect that GR simply *is*
the lens model, it is surprising that this is made an issue..)

[Mod. note: the lens model includes the mass distribution of the lens
-- mjh]


Martin is right. In fact, by "lens model", I (and essentially everyone
working in gravitational lensing) mean "the mass distribution of the
lens". I was referring to the effect of the magnification on the
luminosity function. (There are two competing effects: magnification
makes things brighter, thus more likely to be observed, while it also
means a smaller area of sky is observed, which means things are less
likely to be observed. Which wins out depends on how steep the
luminosity function is.)
  #20  
Old July 1st 12, 02:37 PM posted to sci.astro.research
Eric Flesch
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Posts: 321
Default Beyond IDCS J1426.5+3508

On Sun, 01 Jul 12, Phillip Helbig wrote:
How probable is it that the Moon and the Sun have the same angular size?


Possibly close to 1, due to the anthropic principle: such a moon may
have been needed to give the Earth tectonic and rotational stability
across epochs, else we wouldn't have evolved to be discussing it.
 




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