Einstein Observatory solid state spectrometer observations of M87 and the Virgo cluster
Abstract
X-ray observations of the galaxy M87 and of a region in the Virgo cluster displaced 7 arcmin from the center of M87 are reported. X-ray spectra were obtained at these two locations with the Solid State Spectrometer onboard the Einstein Observatory. Emission lines were observed in both locations, indicating the presence of heavy elements at abundances near solar. There is no strong abundance gradient, within the errors. A temperature gradient has been detected: T increases from about 1.4 keV at the position of M87 to about 3.35 keV 7 arcmin away. There is lower temperature thermal emission at the center of M87 with T about 0.6 keV, consistent with models for cooling flows in this cluster. A mass infall rate of nearly 20 solar masses/yr has been obtained. In addition to the thermal emission, a power-law component has been detected in the spectrum of M87, consistent with that observed by HEAO 1, indicating that this component probably originates in the galaxy itself. Comparison of the results with those of other observers and with theoretical models for this source indicates the presence of intracluster gas having density near 1/1000 per cu cm and temperature of about 30,000,000 K.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1982
- DOI:
- Bibcode:
- 1982ApJ...262...24L
- Keywords:
-
- Galactic Structure;
- Heao 2;
- Intergalactic Media;
- Virgo Galactic Cluster;
- X Ray Sources;
- Black Holes (Astronomy);
- Cooling Flows (Astrophysics);
- Cosmic Gases;
- Emission Spectra;
- Heao 1;
- Line Spectra;
- Satellite-Borne Instruments;
- Spectrometers;
- Stellar Mass Accretion;
- X Ray Spectra;
- Astrophysics