Relativistic ionized accretion disc models of MCG–6-30-15 |
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| Authors: | DR Ballantyne AC Fabian |
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| Institution: | 1Osservatorio Astronomico di Torino, Strada Osservatorio, 20, I-10025 Pino Torinese (TO), Italy;2Department of Astronomy, 474 N. Charter Str., University of Wisconsin, Madison, WI 53706, USA;3Astrophysics Division, Space Science Department of ESA, ESTEC, Postbus 299, 2200 AG Noordwijk, the Netherlands;4Physics Department, 1150 University Avenue, University of Wisconsin, Madison, WI 53706, USA;5TESRE-CNR, via Gobetti 101, I-40129 Bologna, Italy;6Astrophysical Institut, 14882 Postdam, An der Sternwarte 16, Germany;7IFCAI-CNR, via La Malfa 153, I-90146 Palermo, Italy;8Department of Physics and Astronomy, PO Box 87150, Arizona State University, Tempe, AZ 85287-1504, USA |
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| Abstract: | We present BeppoSAX observations of Nova Velorum 1999 (V382 Vel), carried out in a broad X-ray band covering 0.1–300 keV only 15 d after the discovery and again after 6 months. The nova was detected at day 15 with the BeppoSAX instruments which measured a flux F x?1.8×10?11 erg cm?2 s?1 in the 0.1–10 keV range and a 2 σ upper limit F x<6.7×10?12 erg cm?2 s?1 in the 15–60 keV range. We attribute the emission to shocked nebular ejecta at a plasma temperature kT ?6 keV . At six months no bright component emerged in the 15–60 keV range, but a bright central supersoft X-ray source appeared. The hot nebular component previously detected had cooled to a plasma temperature kT <1 keV . There was strong intrinsic absorption of the ejecta in the first observation and not in the second, because the column density of neutral hydrogen decreased from N (H)?1.7×1023 to N (H)?1021 cm?2 (close to the interstellar value). The unabsorbed X-ray flux also decreased from F x=4.3×10?11 to F x?10?12 erg cm?2 s?1 . |
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| Keywords: | stars: individual: V382 Vel novae cataclysmic variables X-rays: stars |
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