Spartan 1 X-ray observations of the Perseus cluster. II. The distribution of flux and hardness ratio out to a radius of 50 arcminutes

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169500· OSTI ID:6260511

Snyder, W A; Kowalski, M P; Cruddace, R G; Fritz, G G; Middleditch, J ^[1]

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1. Naval Research Laboratory, Washington, DC (USA) Los Alamos National Laboratory, NM (USA)

The 1-10 keV X-ray observations of the Perseus Cluster by Spartan 1 have yielded a map of the X-ray emission and the distribution of X-ray hardness ratio with radius from the cluster center. The surface brightness contours are approximately circular within 10 arcmin of the center, but outside this radius become increasingly elongated so that the major axis/minor axis ratio reaches 1.2 beyond 20 arcmin. The position angle of the major axis is about 84-deg east of north within 20 arcmin, consistent with optical results, but may shift to approximately 70 deg at larger radii. The centroid of the X-ray emission lies 2.4 arcmin east of NGC 1275. Also, at radii greater than 20 arcmin in the southeast, coincident with the line of bright galaxies between NGC 1275 and IC 310, there is an enhancement in the X-ray surface brightness. These asymmetries may be evidence that outside 10 arcmin the cluster has not reached dynamic equilibrium. Using a spherically symmetric model, it is found that the intracluster gas is approximately isothermal between radii of 10 arcmin and 50 arcmin, consistent with a temperature of 7.5 + or - 0.5 x 10 to the 7th K. 46 refs.

• OSTI ID: 6260511
• Journal Information: Astrophysical Journal; (USA), Vol. 365; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
GALAXY CLUSTERS
X RADIATION
ASYMMETRY
BRIGHTNESS
COSMIC GASES
COSMIC X-RAY SOURCES
EQUILIBRIUM
INTERGALACTIC SPACE
MATHEMATICAL MODELS
SATELLITES
SPATIAL DISTRIBUTION
COSMIC RAY SOURCES
DISTRIBUTION
ELECTROMAGNETIC RADIATION
FLUIDS
GASES
IONIZING RADIATIONS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
SPACE
640105* - Astrophysics & Cosmology- Galaxies