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/ i : , , _ . . ) ROSAT and ASCA Observations of the Seyfert galaxy 1 H 0419-577 , Identified with LB 1727
| Content Provider | Semantic Scholar |
|---|---|
| Author | Turner, T. John George Nandra Grupe Remillard Leighly Marshall |
| Abstract | We discuss the properties of the Seyfert 1.5 galaxy LB 1727 based upon the analysis of two ASCA observations, a two-month Rosat monitoring campaign, and optical data. The target is identified with the HEAO-A1 source 1H0419-577, so it has been observed by ASCA and ROSAT in order to obtain better X-ray variability and spectra data. Only modest (20%) variability is observed within or between ASCA and BeppoSAX observations in the ,-_ 2 10 keV band. However, the soft X-ray flux increased by a factor of 3 over a period of 2 months, while it was monitored daily by the ROSAT HRI instrument. The hard X-ray continuum can be parameterized as a power-law of slope P ,-1.5 1.6 across 0.7 11 keV in the rest-frame. We also report the first detection of an iron Ka line in this source, consistent with emission from neutral material. The X-ray spectrum steepens sharply below 0.7 keV yielding a power-law of slope F _ 3.2. There is no evidence for absorption by neutral material, intrinsic to the nucleus. If the nucleus is unattenuated, then the break energy between the soft-excess and hard component is 0.7+0.08 keV. An ionized absorber may produce some turn-up in the spectrum at low energies, but a steepening of the underlying continuum is also required to explain the simultaneous ASCA and HRI data. We cannot rule out the possibility that a significant column of ionized material exists in the line-of-sight, if that is true, then the continuum break-energy can only be constrained to lie within the _ 0.1 -0.7 keV band. Subject headings: galaxies:active galaxies:nuclei X-rays: galaxies 1Laboratory for High Energy Astrophysics, Code 660, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 2Universities Space Research Association 3NAS/NRC Research Associate 6Eureka Scientific, Inc. https://ntrs.nasa.gov/search.jsp?R=19980236892 2020-02-01T23:28:41+00:00Z |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980236892.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
