2010/09/27 by Geoffrey C. Bower, Steve Croft, S. Croft +72
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Flux (metallurgy) #Galaxies: Formation, Evolution, Phenomena #Geography #Physics #Radio Astronomy Observations and Technology #Radio telescope #Remote sensing #Sky #Spectral index #Spectral line #Telescope #astro-ph.HE
paper · pdf · doi:10.1088/0004-637x/725/2/1792
Accepted for publication in ApJ; revision submitted with extraneous figure removed
arxiv created 2010/09/27 · openalex publication_date 2010/12/02 · arxiv updated 2015/05/20 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
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.