Infrared spectroscopy of the supersoft X-ray source MR Vel

¹ Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
² Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
³ Instituto Astronômico e Geofísico, Universidade de São Paulo, Brazil

Corresponding author: R. E. Mennickent, rmennick@stars.cfm.udec.cl

Received: 5 November 2002
Accepted: 14 February 2003

Abstract

We describe the infrared spectrum of the galactic supersoft X-ray source MR Vel (RX J0925.7–4758) in the wavelength range of 1.1-2.6 μm. We find Paschen, Brackett, , and neutral and ionized oxygen lines in emission. No traces of the secondary star were found. P-Cygni profiles were observed in Paschen β and Brackett γ, from which we conclude that these lines arise in a wind. Fitting the optical and infrared energy distribution with a supercritical disk model, incorporating white dwarf and secondary star contributions, we were able to constrain the distance to 2-5 kpc, which implies an absolute magnitude M_V between -2 and 0.