An integral field spectroscopic survey for high redshift damped Lyman-α galaxies ^*,**

¹ European Southern Observatory, Casilla 19001, Santiago 19, Chile e-mail: lichrist@eso.org
² Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
³ Centro Astronómico Hispano Alemán de Calar Alto, Calle Jesús Durbán Remón 2,2 04004 Almería, Spain
⁴ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany

Received: 16 September 2006
Accepted: 8 March 2007

Abstract

Aims.We search for galaxy counterparts to damped Lyman-α absorbers (DLAs) at towards nine quasars, which have 14 DLAs and 8 sub-DLAs in their spectra.

Methods.We use integral field spectroscopy to search for Lyα emission line objects at the redshifts of the absorption systems.

Results.Besides recovering two previously confirmed objects, we find six statistically significant candidate Lyα emission line objects. The candidates are identified as having wavelengths close to the DLA line where the background quasar emission is absorbed. In comparison with the six currently known Lyα emitting DLA galaxies the candidates have similar line fluxes and line widths, while velocity offsets between the emission lines and systemic DLA redshifts are larger. The impact parameters are larger than 10 kpc, and lower column density systems are found at larger impact parameters.

Conclusions.Assuming that a single gas cloud extends from the QSO line of sight to the location of the candidate emission line, we find that the average candidate DLA galaxy is surrounded by neutral gas with an exponential scale length of ~5 kpc.