S0 galaxies are highly flattened, disk-shaped stellar systems lacking spiral arms. They
were added to the Hubble Sequence of galaxy types in 1936, in Hubble's book,
"The Realm of the Nebulae," in order to bridge the "catastrophic" gap between
spiral and elliptical galaxies. Since that time, S0 galaxies have been
the subject of intense research to determine their origin. The Near-Infrared
S0 Survey (NIRS0S) is a major project designed to try and unravel the possible
connection between spirals and S0s using properties of the bulges, disks,
and bars in S0 galaxies as compared to spirals. The team consists of Drs. Eija
Laurikainen and Heikki Salo (University of Oulu), Dr. Johan Knapen (Institute of
Astronomy, Canary Islands), and myself. The websites at right summarize
some of the papers published from the survey and some of the results obtained.
NGC 2784 is a typical S0 galaxy.
The Near-Infrared S0 Survey Homepage
The distribution of bar strengths in S0 galaxies as compared to spirals.