Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2009-06-23
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
Accepted for publication by Astronomy and Astrophysics
Scientific paper
10.1051/0004-6361/200912622
[abridged] At the end of the Spitzer cryogenic mission and the onset of the Herschel era, we review our current knowledge on galaxy evolution at IR wavelengths. We also develop new tools for the analysis of background fluctuations to constrain source counts in regimes of high confusion. We analyse a large variety of new data on galaxy evolution and high-z source populations from Spitzer surveys, as well as complementary data from sub-mm (BLAST) and millimetric ground-based observations. These data confirm earlier indications about a very rapid increase of galaxy volume emissivity up to z~1. This is the fastest evolution rate observed for galaxies at any wavelengths. The observed Spitzer counts at 24 micron require a combination of fast evolution for the dominant population and a bumpy spectrum with substantial PAH emission at z~1 to 2. Confusion-limited number counts at longer wavelengths confirm these results. All the present data require that the fast observed evolution from z=0 to 1 flattens around redshift 1 and then keeps approximately constant up to z~2.5 at least. The present-day IR data provide clear evidence for the existence of a distinct population of very luminous galaxies becoming dominant at z > 1. Their cosmological evolution, peaking around z~2, shows a faster decay with cosmic time than lower luminosity systems, whose maximal activity is set around z~1, then supporting an earlier phase of formation for the most luminous and massive galaxies. From a comparison of our results on the comoving IR emissivity with recent estimates of the redshift-dependent stellar mass functions of galaxies, we infer that a large fraction (>=50%) of the IR activity at z > 1 should be due to obscured AGN accretion and that concomitant SF in high-z luminous sources should follow a top-heavy IMF.
Berta Stefano
Franceschini Alberto
Mainetti Gabriele
Marchetti Lucia
Rodighiero Giulia
No associations
LandOfFree
Galaxy evolution from deep multi-wavelength Infrared surveys: a prelude to Herschel does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Galaxy evolution from deep multi-wavelength Infrared surveys: a prelude to Herschel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Galaxy evolution from deep multi-wavelength Infrared surveys: a prelude to Herschel will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-708467