Southern H-Alpha Sky Survey Atlas (SHASSA)

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. The survey covers the southern hemisphere (declinations less than +15 degrees). The observations were taken with a robotic camera operating at Cerro Tololo Inter-American Observatory (CTIO) in Chile.

Four maps are available for this survey : H-alpha, Continuum, Continuum-Corrected (the difference of the H-alpha and Continuum images) and Smoothed Continuum-Corrected (median filtererd to 5 pixels, or 4.0 arcminute resolution to remove star residuals better). The original angular resolution is ~1 arcminute and units of the maps are dR.

Reference

Maps

SHASSA H-alpha SHASSA Continuum

Original WCS data

Poject Website