The NGC 7331 Group, a Stable Group of Galaxies Projected on Stephan's Quartet
Abstract
Summary. The galaxies NGC 733l,NGC 7320,DDO 213, and an anonymous galaxy observed by Shostak form a physical NGC 7331 groupwhich is apparently stable against dynamical disruption. This strengthens the view that NGC 7320, the one member of Stephan's "Quintet" with a discordant redshift, is actually a foreground galaxy lying at the same distance (20 Mpc) as NGC 7331. This conclusion is further supported by Limber and Mathews (1960) who have shown that the remaining four high-redshift galaxies, i.e. "Stephan's quartet", form also a dynamically stable configuration. Key words: group of galaxies stability of groups of galaxies virial theorem discordant redshifts Stephan's "Quintet"
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 1974
- Bibcode:
- 1974A&A....35..441M