Low-Redshift Damped Lyman Alpha Galaxies Towards the Quasars B2 0827+243, PKS 0952+179, PKS 1127-145, and PKS 1629+120

We present optical and near-infrared ground-based imaging results on four low-redshift damped Lyman alpha (DLA) galaxies. The corresponding DLA systems were discovered in our Hubble Space Telescope spectroscopic surveys for DLAs in known strong MgII absorption-line systems towards the quasars B2 0827+243 (z{DLA}=0.525), PKS 0952+179 (z{DLA}=0.239), PKS 1127-145 (z_{DLA}=0.313), and PKS 1629+120 (z{DLA}=0.532). The DLA galaxies span a mixture of morphological types from patchy, irregular, and low-surface-brightness to spiral galaxies. The luminosities range from 0.02L_K^* to 1.2L_K^*. We also discovered several extremely red objects (EROs) in two of these fields and discuss the possibility that they are associated with the DLA galaxies. These observations add to the small but growing list of DLA galaxies at low redshift. At the present time, 14 DLA galaxies in the redshift range $0.05 \lesssim z \lesssim 1$ have been studied. The distributions of DLA galaxy properties for these 14 cases are discussed and some important trends emerge. Low-luminosity dwarf galaxies with small impact parameters dominate this small sample. There is a significantly higher fraction, by a factor of approximately 3, of gas-rich dwarf galaxies at z \approx 0.5 than at z=0. Also, the highest column density systems arise in low surface brightness dwarf galaxies. Both of these results are unexpected in the context of currently-popular models. If these trends are confirmed, it would indicate the presence of a previously unrecognized population of objects which is responsible for the bulk of the neutral hydrogen gas in the universe at z \approx 0.5. We speculate that they might be related to the excess of faint blue galaxies observed at low to moderate redshifts.