850 μm source counts from a high-resolution survey with ALMA
Abstract
The source counts of submillimeter-selected galaxies provide important clues to the evolution of massive, dust-obscured galaxies forming in the early Universe. While existing surveys using single-dish telescopes over the past 15 years have detected thousands of dusty starburst galaxies at z > 1, using their observed number density to constrain models of galaxy evolution is challenging due to the low spatial resolution (10-30") of these observations: distinguishing between a single, ultra-luminous submillimeter source versus a pair of less luminous, merging galaxies blended by the large beam is not possible. We present a measurement of the 850 μm source counts determined directly from high-resolution data taken with ALMA, covering a total area of 7 sq. arcmin down to 0.2-0.4 mJy rms. With a spatial resolution of ~0.5" 4 kpc at z =2), source blending is not expected to be an issue with these data, except for close pairs in the final stage of merging. The methods to derive the source counts from interferometric measurements presented here demonstrate the need for careful accounting of survey biases from these data, which will be important for use in future dedicated galaxy surveys with ALMA.
- Publication:
-
American Astronomical Society Meeting Abstracts #223
- Pub Date:
- January 2014
- Bibcode:
- 2014AAS...22324625S