Zusammenfassung
The extensive ground-based spectroscopy campaign from the VIMOS Ultra-Deep
Survey (VUDS), and the deep multi-wavelength photometry in three very well
observed extragalactic fields (ECDFS, COSMOS, VVDS), allow us to investigate
physical properties of a large sample (~4000 galaxies) of spectroscopically
confirmed faint (i_AB<~25 mag) star-forming galaxies, with and without Lyman
alpha in emission, at z~2-6. The fraction of Lyman alpha emitters (LAEs;
equivalent width (EW)=>20A) increases from ~10% at z~2 to ~40% at z~5-6, which
is consistent with previous studies that employ higher Lyman alpha EW cut. This
increase in the LAE fraction could be, in part, due to a decrease in the dust
content of galaxies as redshift increases. When we compare best-fit SED
estimated stellar parameters for LAEs and non-LAEs, we find that E(B-V) is
smaller for LAEs at all redshifts and the difference in the median E(B-V)
between LAEs and non-LAEs increases as redshift increases, from 0.05 at z~2 to
0.1 at z~3.5 to 0.2 at z~5-6. For the luminosities probed here (~L*), we find
that star formation rates (SFRs) and stellar masses of galaxies, with and
without Lyman alpha in emission, show small differences such that, LAEs have
lower SFRs and stellar masses compared to non-LAEs. This result could be a
direct consequence of the sample selection. Our sample of LAEs are selected
based on their continuum magnitudes and they probe higher continuum
luminosities compared to narrow-band/emission line selected LAEs. Based on our
results, it is important to note that all LAEs are not universally similar and
their properties are strongly dependent on the sample selection, and/or
continuum luminosities.
Nutzer