Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2009-07-29
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
9 pages, accepted for publication in MNRAS
Scientific paper
We extend a previous study of Lyman Alpha Emitters (LAEs) based on hydrodynamical cosmological simulations, by including two physical processes important for LAEs: (a) Lyman Alpha and continuum luminosities produced by cooling of collisionally excited HI in the galaxy, (b) dust formation and evolution; we follow these processes on a galaxy-by-galaxy basis. HI cooling on average contributes 16-18% of the Lyman Alpha radiation produced by stars, but this value can be much higher in low mass LAEs and further increased if the HI is clumpy. The continuum luminosity is instead almost completely dominated by stellar sources. The dust content of galaxies scales with their stellar mass, M_{dust} is proportional to M_*^0.7 and stellar metallicity, Z_*, such that M_{dust} is proportional to Z_*^1.7. As a result, the massive galaxies have Lyman Alpha escape fraction as low as f_alpha=0.1, with a LAE-averaged value decreasing with redshift such that it is (0.33,0.23) at z =(5.7,6.6). The UV continuum escape fraction shows the opposite trend with redshift, possibly resulting from clumpiness evolution. The model successfully reproduces the observed Lyman Alpha and UV luminosity functions at different redshifts and the Lyman Alpha equivalent width scatter to a large degree, although the observed distribution appears to be more more extended than the predicted one. We discuss possible reasons for such tension.
Dayal Pratika
Ferrara Andrea
Saro Alexandro
No associations
LandOfFree
The cool side of Lyman Alpha Emitters 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 The cool side of Lyman Alpha Emitters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The cool side of Lyman Alpha Emitters will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-520876