H-alpha - The 3 surveys

WHAM -- Wisconsin H-Alpha Mapper

Halpha

VTSS -- Virginia Tech Spectral-Line Survey

Halpha

SHASSA -- Southern H-Alpha Sky Survey Atlas

Halpha

Composite -- Finkbeiner (2003)

Halpha

Bit Mask

Halpha

   Bit  Name       Comments
   ---  ---------  -------------------------------------------------------
     0  'WHAM'     WHAM data used (Wisconsin)
     1  'VTSS'     Virginia Tech Spectral line Survey
     2  'SHASSA'   Southern Halpha Sky Survey Atlas
     3  'STAR'     Star removed
     4  'SATUR'    Saturated pixel nearby in continuum exposure
     5  'BRT_OBJ'  Bright star/galaxy - measurements unreliable 
     6  'BIG_OBJ'  Position near LMC, SMC, or M31; no sources removed
     7  'HI_VEL'   High Velocity in WHAM data

Douglas Finkbeiner, dfinkbeiner@cfa.harvard.edu