Integral field spectroscopy of extended Ly emission from the DLA galaxy in Q2233+131

¹ Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
² Potsdam University, Am Neuen Palais 10, 14469 Potsdam, Germany
³ Astronomical Observatory, Volgina 7, 11160 Belgrade 74, Serbia

Corresponding author: L. Christensen, lchristensen@aip.de

Received: 22 September 2003
Accepted: 15 December 2003

Abstract

This paper presents observations of an extended Lyman-α emission nebula surrounding the galaxy responsible for the Damped Lyman-α Absorption (DLA) line in the spectrum of the quasar Q2233+131. With the Potsdam Multi Aperture Spectrophotometer (PMAS) we measure the properties of the extended Lyα emission in an area of having a total line flux of (2.8 ± 0.3) 10^-16 erg cm^-2 s^-1, which at redshift corresponds to a luminosity of ( erg s^-1 and a size of 23 38 kpc. The location of the emission is spatially coincident with the previously detected DLA galaxy, but extends significantly beyond its limb. We argue that the Lyα emission is likely to be caused by an outflow from the DLA galaxy, presumably powered by star formation. In the case of negligible dust extinction, the Lyα luminosity indicates a star-formation rate of 19 ± yr^-1 consistent with that derived from the UV continuum flux from the parent galaxy. The wind velocity indicated by the integral field spectra is of the order of several hundred km s^-1. We find no indication of emission originating in a rotating disk.