How many galaxies will the James Webb Space Telescope reveal in the Universe (that can potentially be seen)?

The present Big Bang theory assumes a "Dark Ages" where neutral (non-ionized) hydrogen absorbs the photons until enough new stars and quasars make enough ultraviolet high energy photons to ionize the neutral hydrogen and thus make space transparent. This would end the “Dark Ages” at around a billion years post bang. Keck telescope recently found galaxies around half a billion years earlier than that... so the "re-ionization" time must now be moved back.

The last new camera installed on the Hubble Telescope lets the telescope take less time to see deeper -- and in its best picture (the Tadpole Galaxy) where an area of 14.9 square arc seconds is viewed, it is said there are 6000 background galaxies viewed.

Thus (60/14.9^0.5*57.3)^2*4*pi*6000 = about 60 billion galaxies --  which are visible in the sphere of the whole sky (the visible Universe) at this proven HST resolution (using a much shorter exposure time than the deep fields).

The hubblesite.org reports the earlier HST "ultra deep field" (taken with the older camera) has about 10,000 galaxies and if extrapolated to fit the whole sphere of the sky would be 12.7 million times larger. 10,000 x 12,700,000 = about 127 billion galaxies resolvable in the Universe (this exposure used a much greater exposure time for resolution than the "tadpole" picture, and used the inferior camera). This record for best resolution still stands at 127 billion "visible" galaxies in the Universe.

So it boils down to the factor of how many times more galaxies the JWST will resolve than the HST now resolves. The JWST is absolutely huge (over 7 times the light gathering power of the HST) and can see much deeper into the redshift using cameras designed for much deeper infrared light than the HST.

If re-ionization is the case, even then there will be some Z where no red shifted infrared photons will be resolved in any optical telescope -- due to neutral hydrogen absorbing the light (Dark Ages). In theory at some Z this would cut off "the view". Theory and observation often differ.

There have been so many surprises by observation -- I would guess we will again be amazed by the power of the upcoming JWST.

So -- I am going to guess at least 600 to 1,000 billion galaxies.

If Big Bang "Dark Ages" theory is incorrect this number will go up much more than a trillion galaxies.

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How many stars will there be in the observable Universe? 

Australian astronomers (Dr. Ken Freeman and Dr. David Malin) are using planetary nebula to find many intergalactic space stars estimated to be equal to the number of stars in all the galaxies. They find this increase in true baryonic mass exceeds the theoretical allowed mass for true baryonic matter. As Big Bang nucleosynthesis and expansion rates are sensitive to baryonic to non-baryonic mass amounts, this becomes a severe problem.

Among other things Big Bang predictions of deuterium to hydrogen particle ratio (the D/H ratio) is very sensitive to the amount of true baryonic matter in the Universe. This increased true baryonic matter leads to a higher baryonic density at the Big Bang event and high density depletes deuterium with more rapid decay to He-4, lowering the predicted D/H ratio. 

After the Big Bang, in theory the D/H ratio can "never go up" anywhere in the interstellar medium or even in stars... but can go lower (e.g. by deuterium fusion to He-4 in stars). This predicted ratio must remain the maximum possible ratio of the interstellar medium for the whole age of the Universe. When theory must lower the D/H predicted ratio, like this estimated doubling the baryonic star mass of the universe, theory will then calculate a much lower D/H ratio and have trouble with this much lower "ceiling" fitting observation.  It is bad enough that observation is already showing some high natural occurrence D/H ratios above the ceiling of predicted ratios.

The D/H value of the Earth's ocean water is much higher than predicted ratios (and is about 10 times the local interstellar medium values). Also D/H values in water of comets and chondrite meteorites is even higher than Earth water -- with a few the same value as the Earth water. There is argument about various mechanisms for such higher than predicted Earth ocean ratios as it is important to explain a reason the Earth D/H ratio is 10 times interstellar medium ratio but lower than most comets and meteorites. This raises the question of where the water on Earth came from being different than surrounding solar system material. Seems there are always more questions than answers.

Besides the huge mass of extra stars found by the Australian astronomers in intergalactic space, the new Spitzer telescope (a tiny tiny version of the upcoming JWSP) is finding many many little galaxies in galaxy clusters that have never been seen before -- further raising the number of stars and baryonic mass of the Universe.

The little Spitzer telescope even resolves deep infrared and found one huge galaxy the HST could barely see with its infrared camera. Spitzer showed this galaxy to be much over 13 billion years distant and found it to be 8 times the mass of our Milky Way (the largest distant galaxy ever found).  The gigantic JWST will be vastly better than the Spitzer Space Telescope (the Spitzer is already seeing some distant things better than the HST using much shorter exposure times). 

See:

http://www.abc.net.au/science/news/space/SpaceRepublish_20267.htm 

paceRepublish_20267.htm

http://en.wikipedia.org/wiki/Spitzer_Space_Telescope 

JWST resolution should lead to a ball park estimate of the number of stars inside the walls of our viewable Universe of a trillion trillion (10^24) stars.

All these stars would be existing inside the depth of our new view of the Universe that will be made possible by the James Webb Space Telescope.

Now we must wait on observation. Part of the fun is anticipation.

Al Alkan

tonyman1989 wrote:

I will put my guess at 1 trillion to 1.2 trillion.

Your guess is probably more accurate as I am trying to be very conservative. The problem is waiting for the James Webb Space Telescope. Already the little Spitzer telescope is the most talked about instrument in the World with cosmologists as it is finding things that HST can not resolve with Hubble's less capable infrared camera. See near the end of these lectures Pg.73 sec 6.6 (about Spitzer):

http://www.astro.caltech.edu/~rse/saas-fee.pdf 

If They refit the HST with the same camera used on the Spitzer, it would be amazing. The reason for this is the angular resolution would be so much better and because HST has 8 times more light gathering capability than Spitzer. The JWST will be like 56 Spitzers as it will have 56 times more light gathering capability than Spitzer plus very great angular resolution!

Just 8 times more light by refitting HST to be like 8 Spitzers will for now "give a view" of the future.

Maybe for a "quick fix" to finding out much quicker (rather than waiting until the JWST is operational) a simple camera installation on the HST will let us know about what the future looks like. If HST had the same camera installation as Spitzer we would be 8 times better off than Spitzer -- right now.

For distant galaxies Spitzer is already better than HST.

I know it may sound like mechanics in Cuba keeping ancient cars running... but: 

How long would it take to get astronauts up there to put Spitzer type cameras on Hubble? How much would it cost? Maybe they will do that on the next service mission... I hope! See:

http://www.nasa.gov/home/hqnews/2007/jun/HQ_07135_HST_Mission_Date.html 

That repair mission is now only scheduled to install another NIR (near infrared camera) and NOT the IRAC camera (that found the most distant huge galaxy) or the MIPS instrument like the Spitzer now uses.

During the year long wait for this mission, I hope they change the mission program and put in the same type cameras as Spitzer uses. 

Chances are they will just install marginally improved out of date stuff and we will have to wait several years on the JWST to see more distant galaxies.

Possibly some will write their Congressional representatives to request this modernization of the old telescope... as this service mission is to be the last one.

Al Alkan 

Yes, the 127 billion record is for the Hubble ultra deep field south (the deepest optical-visual study done so far). 

Infrared is our future. Too bad they don't propose to equipt Hubble to have instruments like Spitzer in the infrared. Already the tiny little Spitzer is finding more and more distant galaxies that Hubble can't see -- and it uses less exposure times. The JWST will surely find vastly more galaxies than Spitzer.

This is evident because the recent seminal paper using Spitzer data (see in the: Cosmologist's Dream) reports the reionization will possibly need to be moved back in time to Z = 15 or so.  In that paper, their graph even shows one galaxy Z >7 having a trillion times solar mass (10^12) in it.

JWST will have 56 times the light gathering ability and much better angular resolution than Spitzer to see huge huge numbers of galaxies Spitzer misses -- and naturally it will see much deeper if reionization must be moved back to Z=15 or so.

Your guess is maybe way too low -- knowing what we do now.  

I wish they would refit Hubble as they are going there on a service mission anyway in a year. Right now they do not propose to refit its view past the "near" infrared installing another NIR camera to replace its old "near infrared" NICMOS camera. Too bad it won't have the latest infrared instruments -- unless some politicians put the squeeze on them. We are just going to have to wait until 2013 (or so) for "first light" of the JWST.

Push for a modern refit job on the Hubble. They could ready new cameras (or to save money, borrow spare ones from the Spitzer Project) in the year long wait for that upcoming Hubble service mission.

That way the name "Hubble" instead of "James Webb" might get the credit in history for finding out the deepest secrets of the Universe. Hubble deserves it for many reasons including discovering the Universal expansion constant (although he never would admit that his constant was caused by the Universe expanding). He "reserved" the cause of his Hubble Constant for future Observation.

Who knows -- even about universal expansion. The Constant not being expansion sounds crazy, but very weird things are found by observation, and Hubble was not crazy.

Al Alkan 

A Hubble internet site said they looked at only one 12.7 millionth of the Sky and saw 10,000 galaxies so that figures 127 billion for the whole Sky.

Yes, I agree it is a long wait. As I recently developed cancer I don't know how long I can wait. Maybe sometime during the next year, a few Hubble service mission astronauts could saunter over to NASA's Spitzer Telescope Warehouse and see if they can borrow a set of "good" Spitzer camera spare parts. 

If they do, I hope it comes with a set of instructions. 

I would feel sorry for Big Bang cosmologists, but I don't care if they just keep observing more and more galaxies -- and there is no "cut off view" by Dark Ages-Reionization Z, and no evolution at high Z for the Big Bang Theory.

Look what the observation of discovering the quantum did to classical mechanics.

Now that observation sounded crazy too.  Let "Hubble" open his infrared eye and try to do it. We might as well know sooner than later -- as eventually the World will know. Hubble said he was willing to wait but maybe "his" telescope will find out.

The facts will go the way of Observation... either way is wonderful... but let us know. Kennedy put a man on the Moon, maybe a kind politician will pull the right strings. 

Al Alkan 

Al Alkan wrote:

As I recently developed cancer I don't know how long I can wait.

Thanks tonyman1989 -- See this website:

http://hubblesite.org/newscenter/archive/releases/2004/07/

It says 1,000,000 seconds of exposure time, and look at items 5. and 7. to get the numbers to multiply to get the 127 billion galaxies in the whole Sky.

Al Alkan

If the reionization Z goes to 15 then the age of the universe would only be 13.7/(1+15)^(3/2) = 0.214 Billion years old if Big Bang Theory can accept such a young age.

The infrared wavelength would then be greater than the range of the new camera the next service mission to Hubble plans to install.  See the service mission's new Hubble wfc3 camera range here:

http://sm4.gsfc.nasa.gov/art/technology/instruments/wfc3_spect.jpg

The 121.6 nm hydrogen lyman alpha line would then be redshifted to "greater than" the 1700 nm maximum infrared wavelength of Hubble's new camera.

Likewise the new Herschel telescope will not resolve the near or mid infrared ranges and can not work at this required wavelength either.

I just hope one or the other -- or better both -- these telescopes scheduled for about a year from now will refit cameras and have proper infrared instruments installed like the tiny little Spitzer telescope now has. 

With such an option open -- why would Astronomers want to wait years and years on the JWST to solve this problem? 

Al Alkan

tonyman1989 wrote:

the big bang model could not handle an age of .25 billion years because we know the earth is 4.6 billion and the oldest star is 13.2 billion.

Yes, if Z=15, the Big Bang theory would have to accomodate a 13.7 - 0.214 = 13.49 Billion year galaxy or star... and in theory a 13.5 billion year old big galaxy is impossible... and a second generation Population I star might be.

A 13.5 billion year population I second or third generation star even has problems. For many eons the first stars were population III or II stars (with no heavy elements) in the evolution of the Big Bang, so how did a population I star contain the uranium used to date it? The problem as you mention is that the oldest (local) star (HE_1523-0901) is so old. This same accurate dating method measures meteorites that fall to Earth from the asteroid belt and shows them to be 4.65 billion years old exactly confirming the age of our forming Solar System. See:

http://en.wikipedia.org/wiki/HE_1523-0901

For this unique HE_1523-0901 local star the ESO-VLT spectrograph in Chile uses radioactive decay (like carbon dating) only using uranium 238 and thorium decay. As we know it also had to be at least a second generation star, so it got it's uranium from a supernova star. That creates a problem for Big Bang evolution. This is especially so because the theory is that this star may have already been fairly old when its companion star formed heavy metals during its supernova event... as the measured age of the metals must be added to the age of the star -- at the time its companion supernovaed.

The ages of globular clusters is still debated with some thinking they are still as old as 16 or more billion years. Even using their lesser age estimates they approximate the age of a Big Bang estimate of 13.7 billion years. They use stellar evolution according to known nuclear physics to predict the age of such stars.

However, recently the studies measuring solar neutrinos has shown that the solar (stellar) evolution must now be extended 0.7 or more billion years older than previously thought. This recent stellar evolution revision makes these globular clusters close to a billion years older than even previously calculated.  

If we give theory the benefit of the doubt, there is still no time for large type galaxies to be found at high Z due to the necessary "evolution" for those very huge type galaxies.

Now is a very exciting time for observation to clear up the confusion. The only problem with "now" is waiting. Observation WILL happen eventually... BUT... all the new "early galaxy discovery" action is in the mid infrared... and the largest "mid infrared" space telescope is the tiny Spitzer space telescope. 

All the big space telescopes with a size to easily observe "very distant" mid infrared objects are only being "fitted" with near infrared (on Hubble ST) or far infrared (on Herschel ST) equipment (not the needed "mid infrared" equipment) making us wait many years for the JWST to be launched. 

I can not imagine what astronomers are thinking! Surely they want to find out the most basic question of the Universe... can the Big Bang accomodate these new "mid infrared"  findings?" -- so why wait years and years and years until 2013+.

JWST is extremely complex and could fail. It will be orbiting too far away for any service missions. Who knows, it could even blow up on the launch pad. We need something sooner.

Lobby NASA for Hubble ST -- and European Space Agency for Herschel ST -- to update to "mid infrared" on next years missions for both telescopes.

Al Alkan 

Al Alkan wrote:

The ages of globular clusters is still debated with some thinking they are still as old as 16 or more billion years.

tonyman1989 wrote:

Al Alkan wrote: The ages of globular clusters is still debated with some thinking they are still as old as 16 or more billion years. Is there any amount of uncertainty?

For many years the age has been estimated by stellar evolution of the dim cool white dwarfs in globular clusters as 16 +/- 2 billion years. See bottom of page 6580:

http://www.pnas.org/cgi/reprint/94/13/6579.pdf?ck=nck

Recent reports are trying to make the value closer to the predicted age of the Universe and even allowing a billion years for such Population I second generation stars to form.

There are a couple of problems with this.

One is that big stars burn out fast and the oldest stars are little and cooling off stellar masses. Such old, dim, cool white dwarfs as they get cooler and older become impossible to see by telescopes, so who knows how old the oldest stars are -- especially looking at all the dark lanes in spiral galaxies that probably contain many many billions of such old stellar remains. I see these dark lanes accumulating on the inner rim of spiral lanes and think that a lot of them must eventually be eaten up by black holes. It is only recently that the numbers of such cool little stars has been estimated to greatly exceed solar size stars.

The second problem is stellar evolution to determine age has extended the age for such white dwarf stars by using nuclear physics studies in Italy and the evolution age was recently further extended by findings of solar type neutrinos... so now such age may require another billion or so years being added to the predicted ages for globular clusters.

Possibly the upcoming ALMA infrared telescope array in Chile (as it will have great sensitivity and angular resolution) will be able to see these cooler stellar masses and use stellar evolution to predict even older ages. It will even be able to see fairly small planets around stars. 

Observation is gradually moving on -- but at an accelerating rate and will eventually let us know. 

Al Alkan