Number of galaxies by type, today

[Barnak]

I'm looking for reliable informations about the % numbers of galaxies in the whole visible universe, by Hubble type (S, SB, S0, E, Irr), for a T0 time slice (i.e. today).

Of course, looking far away into space means we're also looking far away into the past, so distant galactic populations (by type) isn't the same over there, as what we find over here. For consistency, I want to know the best (i.e. most accurate) % evaluation of galaxies at our universal epoch.

On my side, I was able to estimate the following % numbers, and I need a confirmation :

For all galaxies located at a distance < 100 MLY (about 2100 galaxies) :
Irr : ~ 20%
E : ~ 10%
S0 : ~ 20%
S : ~ 20%
SB : ~ 30%

So can I assume that these percentages are the same everywhere (at the same universal time) ?

Any data on this ?

 

[wolram]

I'm looking for reliable informations about the % numbers of galaxies in the whole visible universe, by Hubble type (S, SB, S0, E, Irr), for a T0 time slice (i.e. today).

Of course, looking far away into space means we're also looking far away into the past, so distant galactic populations (by type) isn't the same over there, as what we find over here. For consistency, I want to know the best (i.e. most accurate) % evaluation of galaxies at our universal epoch.

On my side, I was able to estimate the following % numbers, and I need a confirmation :

For all galaxies located at a distance < 100 MLY (about 2100 galaxies) :
Irr : ~ 20%
E : ~ 10%
S0 : ~ 20%
S : ~ 20%
SB : ~ 30%

So can I assume that these percentages are the same everywhere (at the same universal time) ?

Any data on this ?

Wiki says there are 80 billion galaxies

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

This may all so interest you

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

 

[wolram]

Another site that may be helpful

http://arxiv.org/PS_cache/arxiv/pdf/0804/0804.4483v1.pdf

 

[Barnak]

Thanks for the relpy. But apparently, there isn't much info about galactic types (E, S0, S, SB, Irr) and population today from your links.

 

[Vanadium 50]

So can I assume that these percentages are the same everywhere (at the same universal time)

It's probably the best one can do. Looking out, we see (obviously) younger galaxies, so we would have to somehow model their evolution. But worse, we see a biased sample - we see bright galaxies. So we would have to correct twice - and what are these corrections based on? Right - nearby galaxies. So you might as well save yourself the trouble and just look at near galaxies from the get-go.

 

[Chronos]

Discerning the morphology of galaxies beyond Z~1 is problematic. As noted by other posters, large, bright galaxies dominate the population of those observable - which obviously skews the sample. LEDA has the most complete listing available. It is interesting to extrapolate the sample population based on local distributions, but, clearly unreliable. It is highly probable young, small, irregular galaxies were extremely abundant in the early universe.