An ASCA Observation of the Seyfert 2 Galaxy Markarian 3
Abstract
We report preliminary results of an ASCA observation of the Seyfert 2 galaxy Mkn 3. Comparison with previous Ginga and BBXRT observations shows that the observed hard X-ray luminosity above 4 keV decreased by a factor of ~ 3 (intrinsic luminosity by almost a factor of 6) in a period of ~ 3.6 yr. On the other hand, the soft luminosity has not varied significantly in ~ 13 yr, lending support to the extended nature of the soft emission, perhaps dominated by scattering of the nuclear X-rays. ASCA resolves the Fe K line emission into at least two components for the first time. The dominant component at 6.4 keV has an equivalent width of ~ 860 eV and FWHM ~ 10(4) km s(-1) , while the second component has an equivalent width of ~ 190 eV and appears to be narrower than the first. The total intensity of the Fe K emission decreased by factor of over 3 in response to the decrease in the continuum level, implying that a substantial part of the dominant Fe K emission must originate in a region smaller than that responsible for the soft emission. The variability provides direct evidence that the hard X-ray continuum and Fe K line in this Seyfert 2 are being observed directly through the nuclear obscuring material, not in scattered light.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- October 1994
- Bibcode:
- 1994PASJ...46L.167I
- Keywords:
-
- Iron;
- K Lines;
- Line Shape;
- Luminosity;
- Markarian Galaxies;
- Radiant Flux Density;
- Seyfert Galaxies;
- Variability;
- X Ray Astronomy;
- X Ray Scattering;
- X Ray Sources;
- Astronomical Models;
- Charge Coupled Devices;
- Galactic Nuclei;
- Ginga Satellite;
- Heao 2;
- Imaging Spectrometers;
- Plasmas (Physics);
- Rosat Mission;
- Astronomy;
- GALAXIES: ACTIVE;
- GALAXIES: INDIVIDUAL (MKN 3);
- GALAXIES: NUCLEI;
- X-RAYS: GALAXIES