XMM-Newton observations of Nova LMC 2000
Greiner, J.; Schartel, N.; Orio, M.
Germany, Italy, United States, Spain
Abstract
We report on three X-ray observations of Nova LMC 2000 with XMM-Newton at 17, 51 and 294 days after the maximum, respectively. X-ray spectral fits show a concordant decrease of the absorbing column and the X-ray luminosity. No supersoft X-ray emission is detected. The mass of the ejected shell is determined to be (less than) 7.5 x 10-5 M sun. Though data are sparse, one interesting correlation becomes visible: sources with a long-duration supersoft X-ray phase have shorter orbital periods than those with short or no supersoft X-ray phase. This can be understood considering that (i) enough matter has to be accreted in order to ignite the H burning, and (ii) that H burning ceases when the mass of the remaining material (after shell ejection and burning) drops below a certain limit under which the temperature at the bottom of the envelope is too low for the shell burning to compensate the energy loss from the surface.
Partly based on observations collected at the European Southern Observatory, Chile; under proposal 66.D-0391.