The gas mass and star formation rate of star-forming galaxies at z∼1

Optical imaging and spectroscopic surveys of the various deep fields have yielded detailed information on the properties of star-forming galaxies out to very high redshifts, z>>1. However, little is known about the atomic gas in these galaxies, due to the weakness of the HI 21cm line. For large galaxy samples, ``stacking'' of the redshifted HI 21cm emission from the different galaxies allows us to achieve a far higher HI mass sensitivity  than would be possible for individual objects. I will describe the first such HI 21cm stacking experiment at z>1, using Giant Metrewave Radio Telescope (GMRT) HI 21cm spectroscopy of four of the DEEP2 fields to probe the atomic gas mass of star-forming galaxies at z~1.3. I will also discuss results from our stacking of the rest-frame 1.4 GHz radio continuum from the DEEP2 galaxies, which allows us to determine the total median star formation rate (SFR) of the DEEP2 galaxies from the radio-far infrared correlation, and to study the dependence of the median SFR on various galaxy properties. Finally, I will discuss prospects for such studies in the near future using the new receivers and backend of the upgraded GMRT.