From amr w astro.uni.torun.pl  Fri Jul 20 13:06:50 2012
From: amr w astro.uni.torun.pl (Andrzej Marecki)
Date: Fri, 20 Jul 2012 13:06:50 +0200
Subject: [Cosmo-torun] A spiral galaxy at z=2.18
Message-ID: <20120720110650.GA32131@astro.uni.torun.pl>

Can a grand-design *spiral* galaxy be located at a redshift z=2.18?
Yes it can!

http://www.nature.com/nature/journal/v487/n7407/full/nature11256.html

--
am

_______________________________________________
Cosmo-torun mailing list
Cosmo-torun w cosmo.torun.pl
http://cosmo.torun.pl/mailman/listinfo/cosmo-torun


From boud w astro.uni.torun.pl  Fri Jul 20 13:45:04 2012
From: boud w astro.uni.torun.pl (Boud Roukema)
Date: Fri, 20 Jul 2012 13:45:04 +0200 (CEST)
Subject: [Cosmo-torun] A spiral galaxy at z=2.18
In-Reply-To: <20120720110650.GA32131@astro.uni.torun.pl>
References: <20120720110650.GA32131@astro.uni.torun.pl>
Message-ID: <alpine.DEB.2.00.1207201338000.14890@adjani.astro.uni.torun.pl>

On Fri, 20 Jul 2012, Andrzej Marecki wrote:

> Can a grand-design *spiral* galaxy be located at a redshift z=2.18?
> Yes it can!
>
> http://www.nature.com/nature/journal/v487/n7407/full/nature11256.html

Cool!

for z in 10 2.18; do echo $z |cosmdist -v -h 100 -m 0.28 -l 0.733 -t; done

Enter redshift: read parameter: 10.00000 
H_0= 100.00  Omega_matter= 0.28000  Omega_lambda= 0.73300  Omega_radiation = 0.00004950 w_0= -1.00000
cosmological time is 0.337055523 Gyr
Enter redshift: read parameter: 2.18000 
H_0= 100.00  Omega_matter= 0.28000  Omega_lambda= 0.73300  Omega_radiation = 0.00004950 w_0= -1.00000
cosmological time is 2.151303965 Gyr

So if the galaxy "formed" at z=10, then it had only about 1.8 h^-1 Gyr
to build up to the massive disk, according to an FLRW model with
Concordance parameters.


>
> --
> am
>
> _______________________________________________
> Cosmo-torun mailing list
> Cosmo-torun w cosmo.torun.pl
> http://cosmo.torun.pl/mailman/listinfo/cosmo-torun
>

_______________________________________________
Cosmo-torun mailing list
Cosmo-torun w cosmo.torun.pl
http://cosmo.torun.pl/mailman/listinfo/cosmo-torun


From boud w astro.uni.torun.pl  Tue Jul 10 12:45:52 2012
From: boud w astro.uni.torun.pl (Boud Roukema)
Date: Tue, 10 Jul 2012 12:45:52 +0200 (CEST)
Subject: [Cosmo-torun] Newtonian N-body wrong in EdS relativistic 2nd order
 perturbation theory above 10 Mpc
Message-ID: <alpine.DEB.2.00.1207101240290.29485@adjani.astro.uni.torun.pl>

hi everyone

http://arxiv.org/abs/1207.2035
Newtonian versus relativistic cosmology
Authors: Samuel F. Flender, Dominik J. Schwarz

     Abstract: We show how the relativistic matter and velocity power
     spectra behave in different gauges. We construct a new gauge where
     both spectra coincide with Newtonian theory on all
     scales. However, in this gauge there are geometric quantities
     present which do not exist in Newtonian theory, for example the
     local variation of the Hubble parameter. Comparing this quantity
     to second order Newtonian quantities, we find that Newtonian
     theory is wrong on scales larger than 10 Mpc. This undermines the
     reliability of Newtonian cosmological N-body simulations on these
     scales.


What's surprising is that this is still only *perturbation* theory,
it's not fully relativistic, if I understand the paper correctly.
Fully relativistic calculations still remain to be done.

pozdr
boud

_______________________________________________
Cosmo-torun mailing list
Cosmo-torun w cosmo.torun.pl
http://cosmo.torun.pl/mailman/listinfo/cosmo-torun