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STScI will be down completely for electrical work from 2:00 PM Friday, 2 December – 6:00 AM Monday, 5 December, 2016. Mail will be queued and delivered after the work is completed, but there may be a delay. DADS and data processing won't be up until some time Monday morning. Our apologies for the inconvenience.

Please take a very short 6 question survey found on the front page of the MAST Discovery Portal.

Faint Images of the Radio Sky at Twenty-cm

Faint Images of the Radio Sky at Twenty-cm (FIRST) is a systematic survey of the North and South Galactic caps begun in 1993, using the NRAO Very Large Array (VLA) . Typical images are comprised of 1150x1550 1.8" pixels with 5" resolution. Source catalogs are also available including peak and integrated flux densities generated from the high resolution coadded images. The survey yields very accurate (<1 arcsec rms) radio positions of faint (>1 mJy/beam) compact sources. The areas observed were chosen to coincide with the Sloan Digital Sky Survey. For more information, see the VLA FIRST Web Site.

FIRST Northern Sky Coverage

FIRST Southern Sky Coverage