The GALEX Arecibo SDSS Survey

VI. Second data release and updated gas fraction scaling relations

¹ Max-Planck Institut für Astrophysik, 85741 Garching, Germany
e-mail: bcatinel@mpa-garching.mpg.de
² Department of Astronomy, Columbia University, New York, NY 10027, USA
³ Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA
⁴ Commissariat à l’Énergie Atomique (CEA), 91191 Gif-sur-Yvette, France

Received: 21 March 2012
Accepted: 7 June 2012

Abstract

We present the second data release from the GALEX Arecibo SDSS Survey (GASS), an ongoing large Arecibo program to measure the Hi properties for an unbiased sample of  ~1000 galaxies with stellar masses greater than 10¹⁰ M_⊙ and redshifts 0.025 < z < 0.05. GASS targets are selected from the Sloan Digital Sky Survey (SDSS) spectroscopic and Galaxy Evolution Explorer (GALEX) imaging surveys, and are observed until detected or until a gas mass fraction limit of a few per cent is reached. This second data installment includes new Arecibo observations of 240 galaxies, and marks the 50% of the complete survey. We present catalogs of the Hi, optical and ultraviolet parameters for these galaxies, and their Hi-line profiles. Having more than doubled the size of the sample since the first data release, we also revisit the main scaling relations of the Hi mass fraction with galaxy stellar mass, stellar mass surface density, concentration index, and NUV − r color, as well as the gas fraction plane introduced in our earlier work.