The supersoft X-ray phase of nova RS Ophiuchi 2006

J. P. Osborne, K. L. Page, A. P. Beardmore, M. F. Bode, M. R. Goad, T. J. O'Brien, Sumner Starrfield, T. Rauch, J. U. Ness, J. Krautter, G. Schwarz, D. N. Burrows, N. Gehrels, J. J. Drake, A. Evans, S. P S Eyres

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Swift X-ray observations of the ∼60 day supersoft phase of the recurrent nova RS Ophiuchi (RS Oph) 2006 show the progress of nuclear burning on the white dwarf (WD) in exquisite detail. First seen 26 days after the optical outburst, this phase started with extreme variability likely due to variable absorption, although intrinsic WD variations are not excluded. About 32 days later, a steady decline in count rate set in. NLTE model atmosphere spectral fits during the supersoft phase show that the effective temperature of the WD increases from ∼65 eV to ∼90 eV during the extreme variability phase, falling slowly after about day 60 and more rapidly after day 80. The bolometric luminosity is seen to be approximately constant and close to Eddington from day 45 up to day 60, the subsequent decline possibly signaling the end of extensive nuclear burning. Before the decline, a multiply-periodic ∼35 s modulation of the soft X-rays was present and may be the signature of a nuclear fusion driven instability. Our measurements are consistent with a WD mass near the Chandrasekhar limit; combined with a deduced accumulation of mass transferred from its binary companion, this leads us to suggest that RS Oph is a strong candidate for a future supernova explosion. The main uncertainty now is whether the WD is the CO type necessary for a Type Ia supernova. This may be confirmed by detailed abundance analyses of spectroscopic data from the outbursts.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume727
Issue number2
DOIs
StatePublished - Feb 1 2011

Fingerprint

outburst
supernovae
nuclear fusion
falling
explosions
explosion
x rays
luminosity
signatures
modulation
atmospheres
atmosphere
temperature
rate

Keywords

  • Binaries: symbiotic
  • Novae, cataclysmic variables
  • Stars: oscillations
  • X-rays: individual (RS Oph)

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Osborne, J. P., Page, K. L., Beardmore, A. P., Bode, M. F., Goad, M. R., O'Brien, T. J., ... Eyres, S. P. S. (2011). The supersoft X-ray phase of nova RS Ophiuchi 2006. Astrophysical Journal, 727(2). https://doi.org/10.1088/0004-637X/727/2/124

The supersoft X-ray phase of nova RS Ophiuchi 2006. / Osborne, J. P.; Page, K. L.; Beardmore, A. P.; Bode, M. F.; Goad, M. R.; O'Brien, T. J.; Starrfield, Sumner; Rauch, T.; Ness, J. U.; Krautter, J.; Schwarz, G.; Burrows, D. N.; Gehrels, N.; Drake, J. J.; Evans, A.; Eyres, S. P S.

In: Astrophysical Journal, Vol. 727, No. 2, 01.02.2011.

Research output: Contribution to journalArticle

Osborne, JP, Page, KL, Beardmore, AP, Bode, MF, Goad, MR, O'Brien, TJ, Starrfield, S, Rauch, T, Ness, JU, Krautter, J, Schwarz, G, Burrows, DN, Gehrels, N, Drake, JJ, Evans, A & Eyres, SPS 2011, 'The supersoft X-ray phase of nova RS Ophiuchi 2006', Astrophysical Journal, vol. 727, no. 2. https://doi.org/10.1088/0004-637X/727/2/124
Osborne JP, Page KL, Beardmore AP, Bode MF, Goad MR, O'Brien TJ et al. The supersoft X-ray phase of nova RS Ophiuchi 2006. Astrophysical Journal. 2011 Feb 1;727(2). https://doi.org/10.1088/0004-637X/727/2/124
Osborne, J. P. ; Page, K. L. ; Beardmore, A. P. ; Bode, M. F. ; Goad, M. R. ; O'Brien, T. J. ; Starrfield, Sumner ; Rauch, T. ; Ness, J. U. ; Krautter, J. ; Schwarz, G. ; Burrows, D. N. ; Gehrels, N. ; Drake, J. J. ; Evans, A. ; Eyres, S. P S. / The supersoft X-ray phase of nova RS Ophiuchi 2006. In: Astrophysical Journal. 2011 ; Vol. 727, No. 2.
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