The Allen Telescope Array Pi GHz Sky Survey. I. Survey Description and Static Catalog Results for the Boötes Field
The Pi GHz Sky Survey (PiGSS) is a key project of the Allen Telescope Array. PiGSS is a 3.1 GHz survey of radio continuum emission in the extragalactic sky with an emphasis on synoptic observations that measure the static and time-variable properties of the sky. During the 2.5 year campaign, PiGSS will twice observe ~250,000 radio sources in the 10,000 deg^2 region of the sky with b > 30° to an rms sensitivity of ~1 mJy. Additionally, sub-regions of the sky will be observed multiple times to characterize variability on timescales of days to years. We present here observations of a 10 deg^2 region in the Boötes constellation overlapping the NOAO Deep Wide Field Survey field. The PiGSS image was constructed from 75 daily observations distributed over a 4 month period and has an rms flux density between 200 and 250 μJy. This represents a deeper image by a factor of 4-8 than we will achieve over the entire 10,000 deg^2. We provide flux densities, source sizes, and spectral indices for the 425 sources detected in the image. We identify ~100 new flat-spectrum radio sources; we project that when completed PiGSS will identify 10^4 flat-spectrum sources. We identify one source that is a possible transient radio source. This survey provides new limits on faint radio transients and variables with characteristic durations of months.
Additional Information© 2011 American Astronomical Society. Received 2010 July 9; accepted 2010 September 21; published 2010 December 2. The authors acknowledge the generous support of the Paul G. Allen Family Foundation, which has provided major support for design, construction, and operations of the ATA. Contributions from Nathan Myhrvold, Xilinx Corporation, Sun Microsystems, and other private donors have been instrumental in supporting the ATA. The ATA has been supported by contributions from the US Naval Observatory in addition to National Science Foundation grants AST-050690, AST-0838268, and AST-0909245. We dedicate this paper to the memory of the late Don Backer: mentor, colleague, and friend.
Published - Bower2010p12843Astrophys_J.pdf