Soft X-ray morphology of the Virgo, Coma, and Perseus cluster of galaxies

Journal Article · Mon Nov 01 04:00:00 EST 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154767· OSTI ID:7137148

Malina, R; Lampton, M; Bowyer, S

Soft X-ray profiles, with 9' resolution, of the Virgo, Coma, and Perseus clusters of galaxies are presented. The 0.5--3.2 keV profile of Virgo, from a scan parallel to the jet axis, is centered on M87 to within 3', symmetric about M87 and well fitted by an isothermal sphere model with a core radius of 15' (+7', -6') (90% confidence). A limit was set on any M87 point source component of 25(+15, -25) percent of the total cluster flux. Although a point source of 20 percent may be compatible with all available observations, the data, although suggestive, do not require it at a significant level. The first 0.1--0.28 keV band profile of Virgo is extended, symmetric about M87, and well fitted by the model with a core radius of 10' (+12',-5'). For the Coma cluster, scanned at a position angle of 105degree, the 0.5--3.2 keV profile is symmetric, centered to within 3' of the center of the galaxy distribution and is well fitted by an isothermal model with a core radius of 10' (+8',-5'). No evidence for emission from the active galaxy NGC 4874 is found.For the Perseus cluster, scanned along a north-south axis, the 0.5--4.5 keV emission is centered to within 3' of NGC 1275 and is adequately fitted by an isothermal sphere model with a core radius of 4' (+8',-4'). Observations confirm that the X-ray emission is narrower along a north-south axis than along the east-west axis containing the line of bright galaxies. No emission was observed from the galaxies IC 310 or NGC 1265, or the nearby weak X-ray source Algol. In examining the X-ray background at 1degree, 2degree, and 8degree from the cluster, no evidence was found for the enhanced background suggested by some previous observers. The implications of these observations are discussed. Limits are given for the energy dependence of the spatial extent of the clusters indicating that there is no strong trend. (AIP)

• Research Organization: Space Sciences Laboratory, University of California, Berkeley
• OSTI ID: 7137148
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 209:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR DISTRIBUTION
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
COSMOLOGICAL MODELS
DISTRIBUTION
ELECTROMAGNETIC RADIATION
GALAXY CLUSTERS
IONIZING RADIATIONS
MATHEMATICAL MODELS
RADIATIONS
SOFT X RADIATION
SPECTRA
STATISTICAL MODELS
X RADIATION
X-RAY SPECTRA