|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Beyond IDCS J1426.5+3508
http://arxiv.org/abs/1205.3788
The galaxy cluster IDCS J1426.5+3508 at z = 1.75 is the most massive galaxy cluster yet discovered at z 1.4 and the first cluster at this epoch for which the Sunyaev-Zel'Dovich effect has been observed. In this paper we report on the discovery with HST imaging of a giant arc associated with this cluster. The curvature of the arc suggests that the lensing mass is nearly coincident with the brightest cluster galaxy, and the color is consistent with the arc being a star-forming galaxy. We compare the constraint on M200 based upon strong lensing with Sunyaev-Zel'Dovich results, finding that the two are consistent if the redshift of the arc is z ~ 3. Finally, we explore the cosmological implications of this system, considering the likelihood of the existence of a strongly lensing galaxy cluster at this epoch in a lambda-CDM universe. While the existence of the cluster itself can potentially be accomodated if one considers the entire volume covered at this redshift by all current high-redshift cluster surveys, the existence of this strongly lensed galaxy greatly exacerbates the long-standing giant arc problem. For standard lambda-CDM structure formation and observed background field galaxy counts this lens system should not exist. Dear Sirs: I was waiting for this news since several years. Well, if you are patient the truth comes through... The lensed galaxy is the first object seen beyond the supposed origin of the Universe. See also the press release of NASA: [Mod. note: Non-ASCII characters removed, please do this yourself. That is *not* an accurate precis of the abstract, by the way -- mjh] |
#2
|
|||
|
|||
Beyond IDCS J1426.5+3508
On Jun 26, 3:11*pm, jacob navia wrote:
[...] The lensed galaxy is the first object seen beyond the supposed origin of the Universe. Since when did the universe start at z=1? Last time I checked , the CMB was located at z = 1100 or so. Science still agrees that the CMB came _after_ the start of the universe, right? |
#3
|
|||
|
|||
Beyond IDCS J1426.5+3508
Le 27/06/12 07:53, Eric Gisse a écrit :
On Jun 26, 3:11 pm, jacob navia wrote: [...] The lensed galaxy is the first object seen beyond the supposed origin of the Universe. Since when did the universe start at z=1? I do not see what this z=1 has to do with anything in the abstract quoted. Last time I checked , the CMB was located at z = 1100 or so. I do not see what the CMB has to do with this observation. Science still agrees that the CMB came _after_ the start of the universe, right? Well, science can be wrong, because a new observation invalidates an old theory. This happens (and happened) all the time. That is science. Nothing is true forever. It is true until a new observation makes the theory impossible. Now, no astronomer in his sane mind will directly say that the big bang theory is moot. This will happen only in a few years when ore and more observations like this make the BB impossible. Note that paradigm changes are painful but I hope people proposing a new one won't have the problems of Galileo... But look, maybe I have misunderstood something since I am not a professional. You are, and I respect that. As far as I understand it: 1) We have a really MASSIVE cluster at 10 GY from here (3.7 from the supposed "bang"). Note that the lensing confirms the big mass of that cluster. 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. The center of the arc is the central cluster galaxy. 2) The lensing implies that there is a BIG galaxy much farther away, 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. 3) How far away is the lensed galaxy? There are too many suppositions in the paper's calculations. I am confident that the refined observations will break too many "records" to be consistent with a "bang" happening in that past times. But I agree that I am biased, and furthermore, not qualified to really prove my opinions: there is no "start" to the Universe. There are only wrong theories. |
#4
|
|||
|
|||
Posting in ASCII
Le 26/06/12 22:11, jacob navia a ecrit :
[Mod. note: Non-ASCII characters removed, please do this yourself. 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!) [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] |
#5
|
|||
|
|||
Beyond IDCS J1426.5+3508
On Jun 27, 5:42*am, jacob navia wrote:
Le 27/06/12 07:53, Eric Gisse a crit : On Jun 26, 3:11 pm, jacob navia wrote: [...] The lensed galaxy is the first object seen beyond the supposed origin of the Universe. Since when did the universe start at z=1? I do not see what this z=1 has to do with anything in the abstract quoted. You said: "The lensed galaxy is the first object seen beyond the supposed origin of the Universe. " Last time I checked , the CMB was located at z = 1100 or so. I do not see what the CMB has to do with this observation. Again, you said: "The lensed galaxy is the first object seen beyond the supposed origin of the Universe. " Science still agrees that the CMB came _after_ the start of the universe, right? Well, science can be wrong, because a new observation invalidates an old theory. This is not the case here. The only thing that observations like this upset are conventional theories of galactic formation which are very well known to be 'in flux'. This most certainly does not falsify the big bang theory, just like the last few times you imagined it has been. [snip rest] |
#6
|
|||
|
|||
Beyond IDCS J1426.5+3508
Le 29/06/12 08:25, Eric Gisse a écrit :
[snip rest] Well, that's clever Eric. All the concrete arguments are eliminated in a very simple: [snip rest] I deduce then: 1) A cluster of 2.6 x 10^14 M0 in 3.7 GY is nothing special. 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 to fit the bang. 2) The fact that we see a lensed galaxy implies that there is a wide field of BIG galaxies behind that galaxy cluster. That is nothing surprising you say. It is just that fully formed BIG galaxies appear immediately after the supposed bang in high density. Our galaxy formation theories are wrong, not the bang. OK. jacob |
#7
|
|||
|
|||
Beyond IDCS J1426.5+3508
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 idea is that dark matter particles might interact with each other by processes additional to gravity.) 2) The fact that we see a lensed galaxy implies that there is a wide field of BIG galaxies behind that galaxy cluster. What do you mean by "BIG," and why do you think the lensed source is in that category? If you mean physical size, the arc is about 4.8 arcseconds across. If it's at z=4 and lensed by a factor of 10, that would give a physical size of 3.5 kpc. What's wrong with that? 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. -- Help keep our newsgroup healthy; please don't feed the trolls. Steve Willner Phone 617-495-7123 Cambridge, MA 02138 USA |
#8
|
|||
|
|||
Beyond IDCS J1426.5+3508
On 6/29/12 4:41 AM, jacob navia wrote:
2) The fact that we see a lensed galaxy implies that there is a wide field of BIG galaxies behind that galaxy cluster. That is nothing surprising you say. It is just that fully formed BIG galaxies appear immediately after the supposed bang in high density. Our galaxy formation theories are wrong, not the bang. 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 This is about 2.5 percent of the present universe radius assuming expansion from the Big Bang at the speed of light c/H = 1.30E+28 cm where current Hubble parameter(H) is 1/13.7 billion years or 2.31E-18 sec 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? Richard D. Saam |
#9
|
|||
|
|||
Beyond IDCS J1426.5+3508
On Sat, 30 Jun 12, "Richard D. Saam" wrote:
This is about 2.5 percent of the present universe radius assuming expansion from the Big Bang at the speed of light Um, I don't think standard cosmology follows that prescription. With or without inflation, spatial expansion isn't held to be dependent on the speed of light. |
#10
|
|||
|
|||
Beyond IDCS J1426.5+3508
In article , jacob navia
writes: compare the constraint on M200 based upon strong lensing with Sunyaev-Zel'Dovich results, finding that the two are consistent if the redshift of the arc is z ~ 3. For standard lambda-CDM structure formation and observed background field galaxy counts this lens system should not exist. I was waiting for this news since several years. Well, if you are patient the truth comes through... The lensed galaxy is the first object seen beyond the supposed origin of the Universe. You are simply wrong in making this claim. The origin of the universe is at z = infinity. What is discussed is the fact that it seems UNLIKELY that the arc is at redshift 3, based on the numbers of galaxies thought to be at that redshift and the masses of clusters at the redshift of the cluster. However, there are certainly galaxies at redshift 3 and certainly clusters at the redshift of the cluster. This might be a case of "if winning the lottery is very improbable, why does someone win every week". Suppose you read 1000 papers on gravitational lensing. It wouldn't be surprising if one of those reported a result which had a probability of only 1/1000. |
Thread Tools | |
Display Modes | |
|
|