Reanalysis of X-Ray Emission from M87. I. The Single-Phase Medium
Abstract
We reanalyze the density and temperature profiles of the X-ray- emitting gas around M87, assuming a spherically symmetric, single-phase model. For given assumed density and temperature profiles, we predict Einstein HRI and IPC surface brightness distributions as well as FPCS line fluxes, which we compare with the data. We find that a good fit to these data can be obtained and that, with a suitable adjustment of the abundances, the equivalent width of the iron complex at 7 keV as observed by wide-beam instruments can also be explained. In contrast to this, the Einstein SSS spectrum and optically determined mass profiles cannot be accounted for simultaneously with the previous X-ray data. We show that the disagreement of the SSS with our models is due to an inconsistency of the SSS data with that of the other X-ray instruments. Because of this, we find no evidence for the existence of absorption above the Galactic value, contrary to an earlier claim based on SSS data. The disagreement of our models with optical mass data is due either to the assumption of a single-phase model, thus rendering the model unacceptable, or possibly to maximal systematic errors in the FPCS data. We also show that thermal conduction at the Spitzer rate is important in our models, although this conclusion is of limited importance in view of the poor fit of our models to the data.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1994
- DOI:
- 10.1086/173795
- Bibcode:
- 1994ApJ...423..143T
- Keywords:
-
- Astronomical Models;
- Emission Spectra;
- Galactic Radiation;
- Intergalactic Media;
- Mass Spectra;
- X Ray Sources;
- Brightness Distribution;
- Density Distribution;
- Heao 2;
- Proportional Counters;
- Temperature Profiles;
- Thermal Conductivity;
- Astrophysics;
- GALAXIES: COOLING FLOWS;
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M87;
- GALAXIES: INTERGALACTIC MEDIUM;
- RADIATION MECHANISMS: NONTHERMAL;
- X-RAYS: GALAXIES