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The X-ray emission from Nova V382 Velorum: II. The super-soft component observed with BeppoSAX

M. Orio·A. N. Parmar·J. Greiner·H. Ogelman·S. Starrfield·E. Trussoni
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Abstract

Nova Velorum 1999 (V382 Vel) was observed by BeppoSAX 6 months after optical maximum and was detected as a bright X-ray supersoft source, with a count rate 3.454+-0.002 cts/s in the LECS. It was the softest and most luminous supersoft source observed with this instrument. The flux in the 0.1-0.7 keV range was not constant during the observation. It dropped by a factor of 2 in less than 1.5 hour and then was faint for at least 15 minutes, without significant spectral changes. The observed spectrum is not well fit with atmospheric models of a hot, hydrogen burning white dwarf. This is due mainly to a supersoft excess in the range 0.1-0.2 keV, but the fit can be significantly improved at higher energy if at least one emission feature is superimposed. We suggest that a ``pseudocontinuum'' was detected, consisting of emission lines in the supersoft X-ray range superimposed on the thermal continuum of a white dwarf atmosphere. As a result, an accurate determination of the effective temperature and gravity of the white dwarf at this post-outburst stage is not possible.

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M. Orio, A. N. Parmar, J. Greiner, H. Ogelman, S. Starrfield, E. Trussoni. 2002-05-08. The X-ray emission from Nova V382 Velorum: II. The super-soft component observed with BeppoSAX. https://doi.org/10.1046/j.1365-8711.2002.05577.x

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