X-ray Observations of LINER and Starburst Galaxies
| dc.creator | Serlemitsos, P. | |
| dc.creator | Ptak, A. | |
| dc.creator | Yaqoob, T. | |
| dc.date | 1997-01-17 | |
| dc.date.accessioned | 2026-07-07T02:22:44Z | |
| dc.date.available | 2026-07-07T02:22:44Z | |
| dc.description | We present the results of ASCA observations of a heterogenous sample of 15 spiral galaxies. 8 are LINERs or low-luminosity AGN (LLAGN), 5 are starburst galaxies and 2 are normal spiral galaxies. We find that in all cases the ASCA spectra can be described by a canonical model consisting of a power-law with a photon index ~ 1.7-2.0, plus a soft optically thin emission component with kT ~ 0.6-0.8 keV. The implied element abundances are often sub-solar. The soft component is usually extended and the nuclear, point-like emission is sometimes absorbed by column densities in the range log nH ~ 21-23 cm-2. The relative luminosities of the soft and hard components vary from galaxy to galaxy. For the LINERs, the 2-10 keV luminosity of the hard component is typically log L ~ 40-41 ergs/s whereas the 0.5-2.0 keV luminosity of the soft component is typically log L ~ 39-40 ergs/s. For starbursts, the 2-10 keV luminosity of is log L ~ 39-40 ergs/s, somewhat lower than the corresponding luminosity of most of the LINERs in our sample. The hard component is similar to the observed X-ray spectra of quasars and also to the intrinsic X-ray spectra of classical Seyfert galaxies. Most of the galaxies in our sample exhibit no significant (dI/I > 20%) short-term variability (with timescales of a day or less) whereas long-term variability is common. We present a case study of the LINER M81 in detail where there is evidence of large-amplitude (dI/I ~ 70%) variability over several weeks. There is also clear evidence for a broad, complex Fe-K emission line which is compatible with an origin in an accretion disk viewed at ~ 40 deg. These results suggest a strong connection between classical AGN, LINERs, and starburst galaxies. | |
| dc.description | 20 pages, 18 postscript files imbedded as 11 figures | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9701127 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9701127 | |
| dc.identifier | "The Physics of LINERs in View of Recent Observations," 1996, eds. M. Eracleous, A. Koratkar, C. Leitherer, and L. Ho, 70 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/10984 | |
| dc.subject | Astrophysics | |
| dc.title | X-ray Observations of LINER and Starburst Galaxies | |
| dc.type | text |