Galactic cannibalism. III. The morphological evolution of galaxies and clusters

Journal Article · Fri Sep 01 04:00:00 EDT 1978 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/156380· OSTI ID:6879018

Hausman, M A; Ostriker, J P

We present a numerical simulation for the evolution of massive cluster galaxies due to the accretion of other galaxies, finding that after several accretions a bright ''normal'' galaxy begins to resemble a cD giant, with a bright core and large core radius. Observable quantities such as color, scale size, and logarithmic intensity gradient ..cap alpha.. are calculated and are consistent with observations. The multiple nuclei sometimes found in cD galaxies may be understood as the undigested remnants of cannibalized companions. A cluster's bright galaxies are selectively depleted, an effect which can transform the cluster's luminosity function from a power law to the observed form with a steep high-luminosity falloff and which pushes the turnover point to lower luminosities with time. We suggest that these effects may account for apparent nonstatistical features observed in the luminosity distribution of bright cluster galaxies, and that the sequence of cluster types discovered by Bautz and Morgan and Oemler is essentially one of increasing dynamical evolution, the rate of evolution depending inversely on the cluster's central relaxation time.

• Research Organization: Princeton University Observatory
• OSTI ID: 6879018
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 224:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DISTURBANCES
GALACTIC EVOLUTION
GALAXY CLUSTERS
INTERGALACTIC SPACE
LUMINOSITY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SPACE