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arXiv · 1311.2893

X-Ray Grating Observations of Recurrent Nova T Pyxidis During The 2011 Outburst

Benjamin M. Tofflemire·Marina Orio·Kim L. Page·Julian P. Osborne·Stefano Ciroi·Valentina Cracco·Francesco Di Mille·Michael Maxwell
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Abstract

The recurrent nova T Pyx was observed with the X-ray gratings of Chandra and XMM-Newton, 210 and 235 days, respectively, after the discovery of the 2011 April 14 outburst. The X-ray spectra show prominent emission lines of C, N, and O, with broadening corresponding to a full width at half maximum of ~2000-3000 km/s, and line ratios consistent with high-density plasma in collisional ionization equilibrium. On day 210 we also measured soft X-ray continuum emission that appears to be consistent with a white dwarf (WD) atmosphere at a temperature ~420,000 K, partially obscured by anisotropic, optically thick ejecta. The X-ray continuum emission is modulated with the photometric and spectroscopic period observed in quiescence. The continuum at day 235 indicated a WD atmosphere at a consistent effective temperature of 25 days earlier, but with a lower flux. The effective temperature indicates a mass of ~1 solar mass. The conclusion of partial WD obscuration is supported by the complex geometry of non-spherically-symmetric ejecta confirmed in recent optical spectra obtained with the Southern African Large Telescope (SALT) in November and December of 2012. These spectra exhibited prominent [O III] nebular lines with velocity structures typical of bipolar ejecta.

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Benjamin M. Tofflemire, Marina Orio, Kim L. Page, Julian P. Osborne, Stefano Ciroi, Valentina Cracco, Francesco Di Mille, Michael Maxwell. 2013-11-12. X-Ray Grating Observations of Recurrent Nova T Pyxidis During The 2011 Outburst. https://doi.org/10.1088/0004-637x%2F779%2F1%2F22

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