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X-Ray Observations of M87’s Halo

Published online by Cambridge University Press:  30 March 2016

D. Fabricant
Affiliation:
Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA.
M. Lecar
Affiliation:
Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA.
P. Gorenstein
Affiliation:
Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA.

Extract

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We briefly describe the soft X-ray image of M87 obtained using the imaging proportional counter aboard the Einstein Observatory. These data provide further strong evidence for the existence of a massive halo of dark matter surrounding M87 and allow a much more precise determination of its mass. Two pointing positions of the satellite were analyzed; one centered on M87, the other 63’ south and 25’ east of M87. The field of view of the imaging proportional counter is 60’ × 60’, and it attains a two dimensional spatial resolution of ˜ 1.5’ in a spectral range spanning 0.1 to 4.5 keV.

As previous reports had suggested (Gorenstein et al. 1977; Fabricant et al. 1978), the present observations show M87 to be a strong, very extended, thermal X-ray source with a temperature near 2 keV, surrounded by weaker and still more extended emission from hotter gas associated with the Virgo cluster as a whole (Davison, 1978; Lawrence, 1978). We find M87 to have a total 0.5-4.5 keV X-ray luminosity of about 2 × 1043 ergs/sec, and an extrapolated 2-6 keV luminosity of approximately 1 × 1043 ergs/sec. The total mass of gas inferred from the X-ray measurement exceeds 1012 solar masses.

Type
Joint Discussion
Copyright
Copyright © Cambridge University Press 1980

References

Davison, P.J.N.: 1978, M.N.R.A.S. 183, 39P.Google Scholar
Fabricant, D., Topka, K., Harnden, F.R. Jr., Gorenstein, P.: 1978, Ap. J. (Letters) 226, L107.CrossRefGoogle Scholar
Gorenstein, P., Fabricant, D., Topka, K., Tucker, W., and Harnden, F.R. Jr.: 1977, Ap. J.. (Letters) 216, L95.CrossRefGoogle Scholar
Lawrence, A.: 1979, M.N.R.A.S. 185, 423.Google Scholar
Mathews, W.G.: 1978, Ap. J. 219, 413.Google Scholar
Raymond, J.C. and Smith, B.W.: 1977, Ap. J. (Suppl.) 35, 419.Google Scholar