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Publications Of The Astronomical Society Of The Pacific


We have completed a robotic wide-angle imaging survey of the southern sky (delta = +15 degrees to -90 degrees) at 656.3 nm wavelength, the H alpha emission line of hydrogen. Each image of the resulting Southern H alpha Sky Survey Atlas (SHASSA) covers an area of the sky 13 degrees square at an angular resolution of approximately 0.'8 and reaches a sensitivity level of 2 R (1.2 x 10(-17) ergs cm(-2) s(-1) arcsec(-2)) pixel(-1), corresponding to an emission measure of 4 cm(-6) pc and to a brightness temperature for microwave free-free emission of 12 muK at 30 GHz. Smoothing over several pixels allows features as faint as 0.5 R to be detected.


This work is a preprint available from at < a href="" >arXiv:astro-ph/0108518v1< /a >.

Images of individual fields in the survey may be examined on the Web.