Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-08-11
Astrophys.J.597:706-729,2003
Astronomy and Astrophysics
Astrophysics
52 pages, including 17 figures; ApJ in press; a complete version with full resolution figures are available at http://falcon
Scientific paper
10.1086/378635
We study the nature of damped Lya absorption (DLA) systems at z<=1 using a sample of 11 DLA galaxies, for which accurate redshift measurements are available. We demonstrate that the precision of photometric redshifts is sufficient for identifying DLA galaxies, because DLAs are rare and their intrinsically high column density implies a small impact parameter of the host galaxy to the QSO line of sight. We adopt this first large DLA galaxy sample to study the neutral gas cross section of intermediate-redshift galaxies and examine the optical properties of DLA galaxies at z<=1. The results of our study are: (1) the extent of neutral gas around intermediate-redshift galaxies scales with B-band luminosity as R/R_* = [L_B/L_{B_*}]^{\beta} with R_*=24-30 h^{-1} kpc and \beta = 0.26_{-0.06}^{+0.24} at N(HI)=10^{20} cm^{-2}; (2) the observed incidence of the DLAs versus the B-band luminosity of the DLA galaxies is consistent with models derived from adopting a known galaxy B-band luminosity function and the best-fit scaling relation of the neutral gas cross section at M_B - 5\log h <= -17; (3) comparison of the observed and predicted number density of DLAs supports that luminous galaxies can explain most of the DLAs found in QSO absorption line surveys and a large contribution of dwarfs (M_B - 5\log h >= -17) to the total neutral gas cross section is not necessary; (4) of the 11 DLAs studied, 45% are disk dominated, 22% are bulge dominated, 11% are irregular, and 22% are in galaxy groups, indicating that galaxies that give rise to the DLAs span a wide range of morphological types and arise in a variety of galaxy environment; (Abridged)
Chen Hsiao-Wen
Lanzetta Kenneth M.
No associations
LandOfFree
The Nature of Damped Ly-alpha Absorbing Galaxies at z<=1--A Photometric Redshift Survey of Damped Ly-alpha Absorbers 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 Nature of Damped Ly-alpha Absorbing Galaxies at z<=1--A Photometric Redshift Survey of Damped Ly-alpha Absorbers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Nature of Damped Ly-alpha Absorbing Galaxies at z<=1--A Photometric Redshift Survey of Damped Ly-alpha Absorbers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-210871