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Title: X-ray grating observations of recurrent nova T Pyxidis during the 2011 outburst

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 an FWHM of ∼2000-3000 km s{sup –1}, 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 M {sub ☉}. 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 in November and December of 2012. These spectra exhibited prominent [O III] nebular lines with velocity structures typical of bipolar ejecta.
Authors:
;  [1] ; ;  [2] ; ; ;  [3] ;  [4]
  1. Astronomy Department, University of Wisconsin-Madison, 475 N. Charter St., WI 53711 (United States)
  2. Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom)
  3. Department of Physics and Astronomy, Padova University, Vicolo dell'Osservatorio 3, I-35122 Padova (Italy)
  4. Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom)
Publication Date:
OSTI Identifier:
22348535
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 779; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANISOTROPY; ATMOSPHERES; EMISSION; EQUILIBRIUM; MASS; NOVAE; PLASMA DENSITY; SOFT X RADIATION; SPHERICAL CONFIGURATION; SULFUR IONS; SYMMETRY; TELESCOPES; WHITE DWARF STARS; X-RAY SPECTRA