Importance of LSB Universe:
- baryon counts: both the extreme ends of galaxy mass are in the LSB realm, for
most LSB galaxies the fraction of mass in neutral gas exceeds the mass in stars
- star formation history: the range in central surface brightness reflects the
style and rate of past star formation
- galaxy evolution: detectability of LSB galaxies increases with redshift,
understanding of changes in galaxy population with time requires better knowledge of
local population
LSB Surveys:
- Photographic Surveys:
- DDO catalog (van den Bergh 1959)
- UGC catalog (PSS-I, Nilson 1973)
- Virgo/Fornax (Binggeli et al 1985, Ferguson and Sandage 1988)
- PSS-II (Schombert et al 1990's)
- APM (Impey et al 1990's)
- CCD Surveys:
- Dalcanton drift scan (1997)
- O'Neil snap (1997)
- Sloan DSS
Finding LSB objects:
snaps (deeper, wider area> versus scan (better flats, but temporal changes)
standard procedure -> clean, smooth, detect (matched filter)
problems:
- surface brightness limit is determined by limit on flatness
- cleaning removed objects, see Malin galaxies