Novae as a Class of Transient X-ray Sources


Motivated by the recently discovered class of faint (10–10 ergs s) X-ray transients in the Galactic Center region, we investigate the 2–10 keV properties of classical and recurrent novae. Existing data are consistent with the idea that all classical novae are transient X-ray sources with durations of months to years and peak luminosities in the 10–10 ergs s range. This makes classical novae a viable candidate class for the faint Galactic Center transients. We estimate the rate of classical novae within a 15 arcmin radius region centered on the Galactic Center (roughly the field of view of XMM-Newton observations centered on Sgr A*) to be ∼0.1 per year. Therefore, it is plausible that some of the Galactic Center transients that have been announced to date are unrecognized classical novae. The continuing monitoring of the Galactic Center region carried out by Chandra and XMM-Newton may therefore provide a new method to detect classical novae in this crowded and obscured region, where optical surveys are not, and can never hope to be, effective. Therefore, X-ray monitoring may provide the best means of testing the completeness of the current understanding of the nova populations. Subject headings: stars: novae, cataclysmic variables — Galaxy: center — Xrays: binaries CRESST and X-ray Astrophysics Laboratory, NASA/GSFC, Greenbelt, MD 20771; Department of Physics, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 Department of Astronomy, University of Wisconsin, 475 North Charter Street, Madison, WI 53706; INAF – Osservatorio Astronomico di Padova, Vicolo dell’ Osservatorio 5, I-35122 Padova, Italy Kavli Institute of Theoretical Physics, UC Santa Barbara, California 93106 INAF, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy;

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@inproceedings{Mukai2008NovaeAA, title={Novae as a Class of Transient X-ray Sources}, author={Kiyofumi Mukai}, year={2008} }