The Southern H-Alpha Sky Survey Atlas is the product of a wide-angle
digital imaging survey of the H-alpha emission from the warm ionized
interstellar gas of our Galaxy. This atlas covers the southern hemisphere
sky (declinations less than +15 degrees). The observations were taken with
a robotic camera operating at Cerro Tololo Inter-American Observatory (CTIO)
in Chile. The atlas consists of 2168 images covering 542 fields. There are four
images available for each field: H-alpha, Continuum, Continuum-Corrected
(the difference of the H-alpha and Continuum images), and Smoothed (median filtered to 5 pixel, or 4.0 arcminute, resolution to remove star residuals better). The SHASSA website has more details of the data and the status of this and related projects. Images can also be
obtained from the Download Images section at the SHASSA site. Provenance: John E. Gaustad (Swarthmore College), Peter R. McCullough (University of Illinois), Wayne Rosing (Las Cumbres Observatory), and Dave Van Buren (Extrasolar Research Corporation). This is a service of NASA HEASARC.