====== 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. \\
Healpix maps made by D. Paradis.
=== Reference ===
* 'A Robotic Wide-Angle Halpha Survey of the Southern Sky' by Guastad, J. E. et al, 2001, PASP, 113, 1326. https://adsabs.harvard.edu/abs/2001PASP..113.1326G
=== Maps ===
*H-alpha: @@ENV:CADE_FILES_URL:/documents/Ancillary/SHASSA/SHASSA_HA_1_8192_partial.fits|SHASSA_HA_1_8192_partial.fits@@
*H-alpha Continuum-Subtracted: @@ENV:CADE_FILES_URL:/documents/Ancillary/SHASSA/SHASSA_1_8192_partial.fits|SHASSA_1_8192_partial.fits@@
*Continuum: @@ENV:CADE_FILES_URL:/documents/Ancillary/SHASSA/SHASSA_CONT_1_8192_partial.fits|SHASSA_CONT_1_8192_partial.fits@@
*Smoothed Continuum-Subtracted: @@ENV:CADE_FILES_URL:/documents/Ancillary/SHASSA/SHASSA_SM_1_4096.fits|SHASSA_SM_1_4096.fits@@
===HiPS ===
SHASSA HiPS are available in Aladin Collections/Image
=== Original WCS data===
https://amundsen.swarthmore.edu/SHASSA/table_by_field.html
=== Poject Website ===
https://amundsen.swarthmore.edu/SHASSA/