skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Color--absolute magnitude relation for E and S0 galaxies. III. Fully corrected photometry for 405 galaxies: comparison of color distributions for E and S0 field and cluster galaxies. [Virgo, coma, centaurus, and fornax clusters]

Journal Article · · Astrophys. J.; (United States)
DOI:https://doi.org/10.1086/156537· OSTI ID:6353247

Colors in u - V and V - r, corrected for color-aperture gradient, galactic reddening, K dimming, and color--absolute magnitude effect, together with corrected V magnitudes, are listed for 405 galaxies, mostly of E and S0 types, using the data and precepts of Paper II. Color distributions are compared for E and S0 galaxies, divided into field and cluster members so as to test for effects of environment on stellar content and for color differences between the E and S0 types. No differences were found, either between the E and S0 types or between the cluster and field memberships: The colors are independent of the environments represented here, whether the galaxies are disk (S0) or halo (E) systems. There is no change of fully corrected u - V colors with the apparent flattening of S0 galaxies over the range of inclinations from 10/sup 0/ less than or approx. = to i < 90/sup 0/. The limit of ..delta..(u - V) < 0.03 mag over these inclinations shows that the optical depth in V for dust extinction is less than tau = 0.01 for an average S0 galaxy. The equality of color distributions for E and S0 systems in and out of clusters is a necessary condition that the stellar content of S0 galaxies is similar to that of E systems, that there has been no significant upper-main-sequence star formation in S0 galaxies within the past 10/sup 9/ years, and that the environment of the clusters studied here (Virgo, Coma, Centaurus, and Fornax) is not the determining factor in the formation and evolution of S0 systems. Arguments are adduced that most S0 galaxies form along the Hubble sequence rather than change into such forms as a consequence of some environmental process. 6 figures, 1 table.

Research Organization:
Hale Observatories, Pasadena, CA
OSTI ID:
6353247
Journal Information:
Astrophys. J.; (United States), Vol. 225:3
Country of Publication:
United States
Language:
English