Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/229544

Title

The GALEX Arecibo SDSS Survey I: gas fraction scaling relations of massive galaxies and first data release

Author(s)

Catinella, Barbara;  Schiminovich, David;  Kauffmann, Guinevere;  Fabello, Silvia;  Wang, Jing;  Hummels, Cameron;  Lemonias, Jenna;  Moran, Sean M.;  Wu, Ronin;  Giovanelli, Riccardo;  Haynes, Martha P.;  Heckman, Timothy M.;  Basu-Zych, Antara R.;  Blanton, Michael R.;  Brinchmann, Jarle;  Budavari, Tamas;  Goncalves, Thiago;  Johnson, Benjamin D.;  Kennicutt, Robert C.;  Madore, Barry F.;  Martin, Christopher D.;  Rich, Michael R.;  Tacconi, Linda J.;  Thilker, David A.;  Wild, Vivienne;  Wyder, Ted K.

Abstract

We introduce the GALEX Arecibo SDSS Survey (GASS), an on-going large program that is gathering high quality HI-line spectra using the Arecibo radio telescope for an unbiased sample of ~1000 galaxies with stellar masses greater than 10^10 Msun and redshifts 0.025<z<0.05, selected from the SDSS spectroscopic and GALEX imaging surveys. The galaxies are observed until detected or until a low gas mass fraction limit (1.5-5%) is reached. This paper presents the first Data Release, consisting of ~20% of the final GASS sample. We use this data set to explore the main scaling relations of HI gas fraction with galaxy structure and NUV-r colour. A large fraction (~60%) of the galaxies in our sample are detected in HI. We find that the atomic gas fraction decreases strongly with stellar mass, stellar surface mass density and NUV-r colour, but is only weakly correlated with galaxy bulge-to-disk ratio (as measured by the concentration index of the r-band light). We also find that the fraction of galaxies with significant (more than a few percent) HI decreases sharply above a characteristic stellar surface mass density of 10^8.5 Msun kpc^-2. The fraction of gas-rich galaxies decreases much more smoothly with stellar mass. One of the key goals of GASS is to identify and quantify the incidence of galaxies that are transitioning between the blue, star-forming cloud and the red sequence of passively-evolving galaxies. Likely transition candidates can be identified as outliers from the mean scaling relations between gas fraction and other galaxy properties. We have fitted a plane to the two-dimensional relation between the H i mass fraction, stellar surface mass density and NUV-r colour. Interesting outliers from this plane include gas-rich red sequence galaxies that may be in the process of regrowing their discs, as well as blue, but gas-poor spirals.

Publication type

Journal article

Source

Monthly Notices of the Royal Astronomical Society, Vol. 403, no. 2 (Apr 2010), pp. 683-708

Publication year

2010

FOR Code(s)

0201 Astronomical and Space Sciences

Keyword(s)

Fundamental parameters;  Galaxies;  Galaxy evolution;  GALEX Arecibo SDSS Survey;  GASS;  Radio lines;  Ultraviolet

Publisher

Wiley-Blackwell

ISSN

0035-8711

Publisher URL

http://dx.doi.org/10.1111/j.1365-2966.2009.16180.x

Copyright

Copyright © 2010 The Authors. Journal copyright © 2010 Royal Astronomical Society.

Peer reviewed