Are High-Redshift Damped Lyα Galaxies Lyman Break Galaxies?

We use deep HST STIS and NICMOS images of three spectroscopically confirmed galaxy counterparts of high-redshift damped Ly? (DLA) absorbers (one of which is a new discovery) to test the hypothesis that high-redshift DLA galaxies are Lyman break galaxies. If this hypothesis is correct, the emission properties of DLA galaxies must lie within the range of emission properties measured for Lyman break galaxies of similar absolute magnitude. This will be true regardless of selection biases in the sample of detected DLA galaxies. We test this prediction using several emission properties: half-light radius, radial profile (S?rsic n-parameter), optical to near-infrared color, morphology, Ly? emission equivalent width, and Ly? emission velocity structure. In all cases the measured values for the DLA galaxies lie within the range measured for the population of Lyman break galaxies. None of the measurements is in conflict with the prediction. We conclude that the measured emission properties of the three DLA galaxies studied here are consistent with the conjecture that high-redshift DLA galaxies are Lyman break galaxies. We show that this result does not conflict with the observation that the few high-redshift DLA galaxies discovered are mostly fainter than spectroscopically confirmed L* Lyman break galaxies.

[1]  W. Sargent,et al.  Evidence for Rotation in the Galaxy at z = 3.15 Responsible for a Damped Lyman-Alpha Absorption System in the Spectrum of Q2233+1310 , 1997, astro-ph/9701116.

[2]  Stephen J. Warren,et al.  HST images of a galaxy group at z = 2.81, and the sizes of damped Lyα galaxies , 1998 .

[3]  Henry C. Ferguson,et al.  Accepted for publication in the Astrophysical Journal Preprint typeset using L ATEX style emulateapj v. 19/02/01 THE STELLAR POPULATIONS AND EVOLUTION OF LYMAN BREAK GALAXIES 1 , 2001 .

[4]  Damped Lyalpha Absorption Associated with an Early-Type Galaxy at Redshift z=0.16377. , 1997, astro-ph/9707157.

[5]  S. M. Fall,et al.  Cosmic Histories of Stars, Gas, Heavy Elements, and Dust in Galaxies , 1998, astro-ph/9812182.

[6]  F T Nichols,et al.  Unfunded research? I am shocked, shocked! , 1993, JAMA.

[7]  C. Steidel,et al.  An Imaging and Spectroscopic Study of the z=3.38639 Damped Lyman Alpha System in Q0201+1120: Clues to Star Formation Rate at High Redshift , 2000, astro-ph/0010427.

[8]  A. Fontana,et al.  Photometric Redshifts and Selection of High-Redshift Galaxies in the NTT and Hubble Deep Fields , 2000, astro-ph/0009158.

[9]  M. Giavalisco,et al.  The Ultraviolet Spectrum of MS 1512–cB58: An Insight into Lyman-Break Galaxies , 1999, astro-ph/9908007.

[11]  Protogalactic Disk Models of Damped Lyα Kinematics , 1998, astro-ph/9805293.

[12]  The CORALS survey - II. Clues to galaxy clustering around QSOs from $z_\mathsf{abs} \sim z_\mathsf{em}$ damped Lyman alpha systems , 2001, astro-ph/0112135.

[13]  Ross D. Cohen,et al.  Damped Lyman-Alpha Absorption by Disk Galaxies with Large Redshifts. I. The Lick Survey , 1986 .

[14]  The structure and clustering of Lyman-break galaxies , 1998, astro-ph/9807341.

[15]  M. Pettini,et al.  Lyman Limit Imaging of High Redshift Galaxies. III. New Observations of 4 QSO Fields , 1995 .

[16]  J. Prochaska,et al.  Chemical Abundances of the Damped Lyα Systems at z > 1.5 , 1998, astro-ph/9810381.

[17]  Max Pettini Alice E. Shapley Charles C. Steidel Jean-G Giavalisco.  The Rest-Frame Optical Spectra of Lyman Break Galaxies: Star Formation, Extinction, Abundances, and Kinematics* , 2001 .

[18]  C. Impey,et al.  Malin 1: A quiescent disk galaxy , 1989 .

[19]  L. Simard,et al.  Quantitative Morphology of Galaxies in the Hubble Deep Field , 1998, astro-ph/9807223.

[20]  P. Moller,et al.  Extended Lyα emission from a damped Ly α absorber at z=1.93, and the relation between damped Ly α absorbers and Lyman-break galaxies , 1998, astro-ph/9812434.

[21]  P. Hewett,et al.  Limits on the star formation rates of z>2 damped Lyα systems from Hα spectroscopy , 1999, astro-ph/9906175.

[22]  S. M. Fall,et al.  Cosmic chemical evolution , 1995 .

[23]  NICMOS imaging search for high-redshift damped Lyα galaxies , 2001, astro-ph/0105032.

[24]  University of Sydney,et al.  Dust in high redshift galaxies , 1997 .

[25]  M. Dickinson,et al.  The z = 0.8596 damped Ly-alpha absorbing galaxy toward PKS 0454+039 , 1994, astro-ph/9412093.

[26]  Jason X. Prochaska,et al.  On the Kinematics of the Damped Lyman-α Protogalaxies , 1997, astro-ph/9704169.

[27]  Patrick Shopbell,et al.  Caltech Faint Galaxy Redshift Survey. X. A Redshift Survey in the Region of the Hubble Deep Field North , 2000 .

[28]  J. Ge,et al.  Spectroscopy of PKS 0528–250: New Limits on CO Absorption and Emission* , 1997, astro-ph/9708104.

[29]  C. Steidel,et al.  Metal Abundances at z < 1.5: Fresh Clues to the Chemical Enrichment History of Damped Lyα Systems , 1998, astro-ph/9808017.

[30]  S. M. Fall,et al.  Confirmation of Dust in Damped Lyman-Alpha Systems , 1991 .

[32]  C. C. Steidel,et al.  Multiwavelength Observations of Dusty Star Formation at Low and High Redshift , 2000, astro-ph/0001126.

[33]  The z = 0.0912 and z = 0.2212 Damped Lyα Galaxies along the Sight Line toward the Quasar OI 363 , 2000, astro-ph/0010573.

[34]  M. Giavalisco,et al.  Spectroscopic Confirmation of a Population of Normal Star-forming Galaxies at Redshifts z > 3 , 1996, astro-ph/9602024.

[35]  Michael Rauch,et al.  Damped Lyα Absorber at High Redshift: Large Disks or Galactic Building Blocks? , 1998 .

[36]  Rodger I. Thompson,et al.  NICMOS Imaging of the Damped Lyα Absorber at z = 1.89 toward LBQS 1210+1731: Constraints on Size and Star Formation Rate , 2000, astro-ph/0002445.

[37]  S. G. Djorgovski,et al.  Identification of a galaxy responsible for a high-redshift Lyman-α absorption system , 1996, Nature.

[38]  M. Steinmetz,et al.  Damped Lyα Absorber and the Faint End of the Galaxy Luminosity Function at High Redshift , 1999, astro-ph/9911447.

[39]  J. Cohen.  Lost and Found: The Damped Lyα Absorbers in the QSO OI 363 , 2000, astro-ph/0012109.