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An old galaxy at z=7.1
The scientific paper is he
http://www.eso.org/public/archives/r...8/eso1508a.pdf The press release is he http://www.eso.org/public/news/eso1508/ From the paper's abstract: quote Here we report thermal dust emission from an archetypal early universe star-forming galaxy, A1689-zD1. We detect its stellar continuum in spectroscopy and determine its redshift to be z = 7.5+/- 0.2 from a spectroscopic detection of the Ly alpha break. A1689-zD1 is representative of the star-forming population during reionisation, with a total star- formation rate of about 12 M sun per yr. The galaxy is highly evolved: it has a large stellar mass, and is heavily enriched in dust, with a dust-to-gas ratio close to that of the Milky Way. Dusty, evolved galaxies are thus present among the fainter star-forming population at z 7, in spite of the very short time since they first appeared. end quote Note the language: They do not say "We have a result that contradicts obviously the Big Bang theory". [Mod. note: that's because it doesn't -- mjh] They say in the press release quote 'Although the exact origin of galactic dust remains obscure,' explains Darach Watson, 'our findings indicate that its production occurs very rapidly, within only 500 million years of the beginning of star formation in the Universe -- a very short cosmological time frame, given that most stars live for billions of years.' end quote We have then: (1) Our galaxy is ready to form stars almost immediately after the supposed "bang". (2) It enters immediately into a star forming frenzy that stops abruptly to give the impression of an aged galaxy forming only around 12 stars per year. (3) Somehow it manages to form enormous quantities of DUST, a tell-tale sign of mature galaxies. AMAZING the explanations of proponents of BB Theory! This is a very preliminary result of ALMA. Now that this first result is out, I am confident that we will see more and more such surprises in the very near future. jacob --------------------------------------------- To the moderator: I copied from the abstract, opened up "vi", saved in a file, eliminated all non ascii characters, verified with "od -c" recopied into the [Mod. note: non-ASCII characters (the quotes cut and pasted from the press release) manually removed as usual -- mjh] |
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An old galaxy at z=7.1
On Tuesday, March 3, 2015 at 1:48:40 PM UTC-5, jacob navia wrote:
The scientific paper is he http://www.eso.org/public/archives/r...8/eso1508a.pdf The press release is he http://www.eso.org/public/news/eso1508/ Paper is available at arXiv.org |
#3
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An old galaxy at z=7.1
On 3/3/15 12:48 PM, jacob navia wrote:
The scientific paper is he http://www.eso.org/public/archives/r...8/eso1508a.pdf The press release is he http://www.eso.org/public/news/eso1508/ I assume this all falls within the Big Bang theory. But interestingly, The paper indicates "unknown dust temperature" and the press release indicates "cold gas and dust emissions" How cold is cold? Is the dust at CMBR temperature at z = 7.1 2.7*(1+7.1)^1 = 22 K or even lower? Richard D Saam |
#4
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An old galaxy at z=7.1
Le 03/03/2015 19:48, jacob navia a écrit :
Note the language: They do not say "We have a result that contradicts obviously the Big Bang theory". [Mod. note: that's because it doesn't -- mjh] OK. Let's go in steps. Step BIG A: Dust ---------- 1) Dust production in galaxies is a cumulative process. The older the galaxy, the more dust it has. This is because supernova explosions produce the dust, as has been recently found. [1], [2]. 2) The galaxy A1689-zD1 has the same level of dust as our galaxy that is probably 12 billion years old. Since that galaxy is at z= 7.5, it is observed at a time when the universe was around 700 million years old, hence it can't be older than that [3]. To accomodate observations with an age of both 0.7 Gy and 12 Gy we must assume some process is eliminating dust in the milky way, process that doesn't happen in A1689-zD1. Or maybe some other mysterious and obviously "ad hoc" process. I am open to suggestions by BB people. Step BIG B: Star formation. The galaxy A1689-zD1 (if I understood the paper correctly) makes only 12 stars like the sun per year. In the paper, we have: quote The galaxy has already formed much of its stars and metals. Taken together, these lines of evidence point to a picture of A1689-zD1 consistently forming stars at a moderate rate since z ~ 9, or possibly having passed through its extreme starburst very rapidly and now in a declining phase of star-formation. end quote Well, that must have been an EXTREMELY rapid star formation phase: just 500 million years for forming all the millions of stars that make a galaxy! We should subtract the "dark ages" time that has been shrinking a LOT but should be at least 100 - 150 Million years. That leaves us with only 350 Million years to form all those stars! Perspective I see that the arguments that I have advanced here since at least 2005 are being confirmed. In a message here on Sep 28th, 2005 I pointed out That HUDF-JD2 that at that time was observed with 6 z 8 that had stopped star formation. That galaxy has 8 times the mass of the milky way. In another message on Nov 24 2004 I was reporting that BB theory had "exploded" because of the discovery of a black hole 1 billion solar masses was discovered at 12.8 billion ly. Five days ago astronomers discovered at the same distance a black hole with 12 billion solar masses. As the observable universe expands (because of better telescope technology) all my previous arguments are confirmed... [1] http://phys.org/news/2013-01-herschel-cosmic.html [2] http://www.space.com/26482-cosmic-du...xplosions.html [3] http://www.astro.ucla.edu/~wright/CosmoCalc.html I just plugged z=7.5 in the "z" parameter leaving all other parameters at their default values. |
#5
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An old galaxy at z=7.1
In article ,
jacob navia wrote: 1) Dust production in galaxies is a cumulative process. The older the galaxy, the more dust it has. This is because supernova explosions produce the dust, as has been recently found. [1], [2]. 2) The galaxy A1689-zD1 has the same level of dust as our galaxy that is probably 12 billion years old. No. Read the paper. It has the same *gas to dust ratio*. It does not have the same *amount of dust*. There is much less gas, much less dust and many fewer stars than in the MW. Well, that must have been an EXTREMELY rapid star formation phase: just 500 million years for forming all the millions of stars that make a galaxy! We should subtract the "dark ages" time that has been shrinking a LOT but should be at least 100 - 150 Million years. That leaves us with only 350 Million years to form all those stars! The estimated stellar mass is 1.7 x 10^9 solar masses. So that's a star formation rate of about 5 solar masses a year by your calculation, actually less than the current star formation rate (which they seem to have estimated by adding the UV and IR numbers). In another message on Nov 24 2004 I was reporting that BB theory had "exploded" because of the discovery of a black hole 1 billion solar masses was discovered at 12.8 billion ly. Five days ago astronomers discovered at the same distance a black hole with 12 billion solar masses. As the observable universe expands (because of better telescope technology) all my previous arguments are confirmed... None of these are, or ever have been, arguments against the BB model because they don't present any *quantitative* argument that these things cannot be observed in the BB model. Numbers matter. Waving your hands about and claiming that selected observations are consistent with your preconceptions is not science. Martin -- Martin Hardcastle School of Physics, Astronomy and Mathematics, University of Hertfordshire, UK Please replace the xxx.xxx.xxx in the header with herts.ac.uk to mail me |
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An old galaxy at z=7.1
Le 04/03/2015 09:20, Martin Hardcastle a écrit :
In article , jacob navia wrote: 1) Dust production in galaxies is a cumulative process. The older the galaxy, the more dust it has. This is because supernova explosions produce the dust, as has been recently found. [1], [2]. 2) The galaxy A1689-zD1 has the same level of dust as our galaxy that is probably 12 billion years old. No. Read the paper. It has the same *gas to dust ratio*. It does not have the same *amount of dust*. There is much less gas, much less dust and many fewer stars than in the MW. That's exactly what I said. The same level of dust. Well, that must have been an EXTREMELY rapid star formation phase: just 500 million years for forming all the millions of stars that make a galaxy! We should subtract the "dark ages" time that has been shrinking a LOT but should be at least 100 - 150 Million years. That leaves us with only 350 Million years to form all those stars! The estimated stellar mass is 1.7 x 10^9 solar masses. So that's a star formation rate of about 5 solar masses a year by your calculation, actually less than the current star formation rate (which they seem to have estimated by adding the UV and IR numbers). Looking this a little bit ore, I went to one of the many sites that accept the BB Theory as true: The "James Webb Space Telescope" site of NASA. There it says: quote Until around 400 million years after the Big Bang, the Universe was a very dark place. There were no stars, and there were no galaxies. end quote This would mean that our galaxy make all the stars and all that dust in 100 million years, supposing that the authors of the paper are right whe they suppose that the galaxy was fully developed at z=9. A more troublesome fact for BB theory is the report of the Planck satellite: (http://physicsworld.com/cws/article/...smic-dark-ages) quote "After the CMB was released, the universe was still very different from the one we live in today, and it took a long time until the first stars were able to form," says Marco Bersanelli of Università degli Studi di Milano, Italy. "Planck's observations of the CMB polarization now tell us that these 'dark ages' ended some 550 million years after the Big Bang – more than 100 million years later than previously thought," he adds end quote That would mean that this galaxy couldn't exist because according to observations it was fully formed (and with a lot of DUST!) 700 million years after the supposed "bang". It would need to be fully formed in only 150 million years !!! Anyway: What you calculate above is the rate needed to form the stars seen, but the TOTAL number of stars created is MUCH higher since there must be a lot of stars that were created, lived and died to make all that dust! All that in just 150 million years. In another message on Nov 24 2004 I was reporting that BB theory had "exploded" because of the discovery of a black hole 1 billion solar masses was discovered at 12.8 billion ly. Five days ago astronomers discovered at the same distance a black hole with 12 billion solar masses. As the observable universe expands (because of better telescope technology) all my previous arguments are confirmed... None of these are, or ever have been, arguments against the BB model because they don't present any *quantitative* argument that these things cannot be observed in the BB model. The gas to dust ratio of a galaxy is not a *quantitative* argument? ??? Numbers matter. Yes. Waving your hands about and claiming that selected observations are consistent with your preconceptions is not science. Sorry but I can repeat the same sentence to you. Waving your hands at the mounting evidence that we are seeing in the supposed "dark ages" fully developed and ancient galaxies is not science. But we can just wait a little bit. ALMA is just BEGINNING to be used. In this year or the next we will find an even OLDER galaxy much FURTHER away. |
#7
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An old galaxy at z=7.1
In article ,
jacob navia wrote: That's exactly what I said. The same level of dust. So why do you think that's relevant? What calculation have you done that suggests that the *gas to dust ratio* should be different in a young galaxy and the MW? In the BB model both gas and dust will evolve with time... Looking this a little bit ore, I went to one of the many sites that accept the BB Theory as true: The "James Webb Space Telescope" site of NASA. There it says: quote Until around 400 million years after the Big Bang, the Universe was a very dark place. There were no stars, and there were no galaxies. end quote I'm not really interested in defending random websites, which are often written by and for journalists... This would mean that our galaxy make all the stars and all that dust in 100 million years, supposing that the authors of the paper are right whe they suppose that the galaxy was fully developed at z=9. ..... but that basically means that the star formation rate would have to be about the same through the galaxy's lifetime as the measured value (given the errors). So what's the problem? quote "After the CMB was released, the universe was still very different from the one we live in today, and it took a long time until the first stars were able to form," says Marco Bersanelli of Università degli Studi di Milano, Italy. "Planck's observations of the CMB polarization now tell us that these 'dark ages' ended some 550 million years after the Big Bang -- more than 100 million years later than previously thought," he adds end quote That would mean that this galaxy couldn't exist because according to observations it was fully formed (and with a lot of DUST!) 700 million years after the supposed "bang". It would need to be fully formed in only 150 million years Of course it's not fully formed, where do you get that from? It is about 1% of the mass of the Milky Way at z=0, and a small fraction of the physical size. However, it only needs to form 10 solar masses a year to reach that mass. Again, you are claiming that's a problem without any evidence to support your claim. What you calculate above is the rate needed to form the stars seen, but the TOTAL number of stars created is MUCH higher since there must be a lot of stars that were created, lived and died to make all that dust! Not really -- the number of stars that have died to make the dust will be a pretty small fraction of the total mass. Look up the concepts of 'initial mass function' and 'main sequence lifetime of stars'. This is all elementary first-year astronomy that it's really useful to know before setting up as a cosmologist! The gas to dust ratio of a galaxy is not a *quantitative* argument? No, because it's not an argument at all. Prove to me from first principles that that gas to dust ratio cannot possibly be achieved in 1-3 hundred Myr and I'll agree you have a point. (But you can't.) Sorry but I can repeat the same sentence to you. Waving your hands at the mounting evidence that we are seeing in the supposed "dark ages" fully developed and ancient galaxies is not science. Again -- describing this galaxy as 'fully developed' is nonsense, and you have no evidence at all that it's 'ancient'. Martin -- Martin Hardcastle School of Physics, Astronomy and Mathematics, University of Hertfordshire, UK Please replace the xxx.xxx.xxx in the header with herts.ac.uk to mail me |
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An old galaxy at z=7.1
On Wednesday, March 4, 2015 at 9:51:32 AM UTC-5, Martin Hardcastle wrote:
In article , jacob navia wrote: That's exactly what I said. The same level of dust. So why do you think that's relevant? What calculation have you done that suggests that the *gas to dust ratio* should be different in a young galaxy and the MW? In the BB model both gas and dust will evolve with time... ------------------------------------------------------------ Here is a direct, straightforward question that I would like to have answered. What quantitative or unique qualitative empirical result would lead us to think that there is a problem with our theoretical model of the early period of expansion? I presume that there are some limits to what the existing model could account for. So what are these "lines in the sand" that do offer clear and definitive tests of the model? |
#9
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An old galaxy at z=7.1
In article ,
Robert L. Oldershaw wrote: Here is a direct, straightforward question that I would like to have answered. What quantitative or unique qualitative empirical result would lead us to think that there is a problem with our theoretical model of the early period of expansion? I presume that there are some limits to what the existing model could account for. So what are these "lines in the sand" that do offer clear and definitive tests of the model? Well, if we stick to galaxy evolution and want a killer observation of a single galaxy, it would be very hard to explain a stellar population that looked older than the universe (not impossible, because estimating the age of stellar populations relies on the assumption that the initial mass function is known, and if you can somehow arrange for no massive stars to form you mimic an old stellar population, but pretty hard). Of course, if there was no big bang but redshift is a measure of distance (tired light?) then we should see plenty of old stellar populations in high-redshift galaxies just as we see plenty of old stellar populations in low-redshift galaxies: but we don't. Or, to pick another example, we could find a galaxy so massive that it's clearly impossible for it to have formed its stellar population in the lifetime of the universe (but that's tough to prove because it relies on knowing what an implausible star formation rate is; and the current example clearly isn't such an object). What people who are actually working in this area do is to try to model the formation of galaxies based on what we know about the initial spectrum of mass perturbations from the CMB and on the relevant physics of dark matter, gas and star formation, and then see if their models agree with observable properties of the galaxy population (*not* of individual objects, since there will necessarily be large scatter among galaxies). This is tough to do but one can imagine that it could clearly lead to predictions that were completely at variance with observations (and moreover *should* do so if the BB model was wrong, since no other model will predict the same relationship between the CMB fluctuations and the properties of galaxies). But actually such models are in good agreement with what's observed. (http://arxiv.org/abs/1301.2685 is an example of this: first ghit for 'high-redshift galaxy mass function'; haven't read any more of it than the abstract.) Anyone wanting to demonstrate that the BB model is wrong from galaxy formation needs to do it this way to be taken seriously. (There are of course many other tests of the BB model.) Martin -- Martin Hardcastle School of Physics, Astronomy and Mathematics, University of Hertfordshire, UK Please replace the xxx.xxx.xxx in the header with herts.ac.uk to mail me |
#10
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An old galaxy at z=7.1
On Wednesday, March 4, 2015 at 1:30:08 PM UTC-5, Robert L. Oldershaw wrote:
------------------------------------------------------------ Here is a direct, straightforward question that I would like to have answered. What quantitative or unique qualitative empirical result would lead us to think that there is a problem with our theoretical model of the early period of expansion? There are many possible clear and definitive tests but here's a simple one -- find any object that has an origin more than 13.8 billion years ago. This could be a globular cluster in our Galaxy more than 13.8 billion years old, or a galaxy at z = 7.5 that is more than 700 million years old. Note that in both cases - Galactic globular clusters and high redshift galaxies -- there are objects with an origin more than ~13 billion years ago. But we have never found an object with an origin 14 billion or more years ago. |
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