X-ray variability in M87
Abstract
We present evidence for X-ray variability from the core and from knot A in the M87 jet based on data from two observations with the Einstein Observatory High Resolution Imager (HRI) and three observations with the ROSAT HRI. The core intensity showed a 16 per cent increase in 17 months (1979-80) a 12 per cent increase in the 3 years 1992 to 1995; and a 17 per cent drop in the last half of 1995. The intensity of knot A appears to have decreased by 16 per cent between 1992 June and 1995 December. Although the core variability is consistent with general expectations for AGN, the changes in knot A provide constraints on the X-ray emission process and geometry. Thus we predict that the X-ray morphology of knot A will differ significantly from the radio and optical structure.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 1997
- DOI:
- 10.1093/mnras/284.4.L21
- arXiv:
- arXiv:astro-ph/9612055
- Bibcode:
- 1997MNRAS.284L..21H
- Keywords:
-
- GALAXIES: ACTIVE;
- GALAXIES: INDIVIDUAL: M87;
- GALAXIES: JETS;
- X-RAYS: GALAXIES.;
- Astrophysics
- E-Print:
- 9 pages latex plus 6 ps figs. To appear in Monthly Notices of the RAS