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Extraordinary luminous soft x-ray transient maxi j0158-744 as an ignition of a nova on a very massive o-ne white dwarf

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posted on 01.02.2016, 12:27 by M. Morii, H. Tomida, M. Kimura, F. Suwa, H. Negoro, M. Serino, J. A. Kennea, Kim L. Page, P. A. Curran, F. M. Walter, N. P. M. Kuin, T. Pritchard, S. Nakahira, K. Hiroi, R. Usui, N. Kawai, Julian Paul Osborne, T. Mihara, M. Sugizaki, N. Gehrels, M. Kohama, T. Kotani, M. Matsuoka, M. Nakajima, P. W. A. Roming, T. Sakamoto, K. Sugimori, Y. Tsuboi, H. Tsunemi, Y. Ueda, S. Ueno, A. Yoshida
We present the observation of an extraordinary luminous soft X-ray transient, MAXI J0158–744, by the Monitor of All-sky X-ray Image (MAXI) on 2011 November 11. This transient is characterized by a soft X-ray spectrum, a short duration (1.3 × 10[Superscript: 3] s < ΔTd < 1.10 × 10[Superscript: 4] s), a rapid rise (<5.5 × 10[Superscript: 3] s), and a huge peak luminosity of 2 × 10[Superscript: 40] erg s–1 in 0.7-7.0 keV band. With Swift observations and optical spectroscopy from the Small and Moderate Aperture Research Telescope System, we confirmed that the transient is a nova explosion, on a white dwarf in a binary with a Be star, located near the Small Magellanic Cloud. An early turn-on of the super-soft X-ray source (SSS) phase (<0.44 days), the short SSS phase duration of about one month, and a 0.92 keV neon emission line found in the third MAXI scan, 1296 s after the first detection, suggest that the explosion involves a small amount of ejecta and is produced on an unusually massive O-Ne white dwarf close to, or possibly over, the Chandrasekhar limit. We propose that the huge luminosity detected with MAXI was due to the fireball phase, a direct manifestation of the ignition of the thermonuclear runaway process in a nova explosion.

History

Citation

Astrophysical Journal, 2013, 779 (2), 118

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

Version

VoR (Version of Record)

Published in

Astrophysical Journal

Publisher

IOP Publishing LTD

issn

0004-637X

eissn

1538-4357

Acceptance date

03/10/2013

Copyright date

2013

Available date

01/02/2016

Publisher version

http://iopscience.iop.org/article/10.1088/0004-637X/779/2/118/meta

Language

en