Peculiar velocities of cD galaxies - MX spectroscopy of Abell 1795

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/185258· OSTI ID:6674134

Hill, J M; Lesser, M P; Hintzen, P; Oegerle, W R; Romanishin, W

Spectroscopic observations of galaxies in the Abell 1795 field have been obtained using the MX multiple-object spectrograph on the Steward Observatory 2.3 m telescope. Redshifts are presented for 46 galaxies, including 41 cluster members. It is found that the A1795 cD galaxy is not at rest in the cluster gravitational potential well; it has a peculiar radial velocity, cz, of 365 km/s, and the hypothesis that the mean cluster velocity is as large as the cD's velocity can be rejected at the 99.5 percent confidence level. This conclusion is supported by spectroscopic data for the cooling flow gas found in the central region of the cluster; this gas, except for the portion coincident with the cD nucleus, lies at the velocity derived for the cluster mean. It is suggested that current models of the formation of cD galaxies are unlikely to account for the large peculiar velocities of the cD galaxies in A1795 and A2670 unless substantial subclustering is still present. However, the available data show no evidence for velocity subclustering in either A1795 or A2670. 25 references.

• Research Organization: Steward Observatory, Tucson, AZ (USA); NASA, Goddard Space Flight Center, Greenbelt, MD (USA); Space Telescope Science Institute, Baltimore, MD (USA); Arizona State Univ., Tempe (USA)
• OSTI ID: 6674134
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 332; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
FLUID FLOW
GALACTIC EVOLUTION
GALAXIES
GALAXY CLUSTERS
GAS FLOW
MATHEMATICAL MODELS
MORPHOLOGY
RADIAL VELOCITY
RED SHIFT
SPECTROSCOPY
VELOCITY