Second XMM/RGS spectrum of V2491 Cyg
ATel #1573; J.-U. Ness and S. Starrfield (Arizona State University), R. Gonzalez and E. Kuulkers (ESAC), J. P. Osborne and K. Page (University of Leicester), G. Schwarz and K. M. Vanlandingham (West Chester University), J. J. Drake (Smithsonian Astrophysical Observatory), M. Hernanz (CSIC-IEEC), G. Sala (MPE Garching), A. Evans (Keele University), N. Gehrels (NASA-GSFC), P. Hauschildt (Hamburger Sternwarte), J. Krautter (Landessternwarte Heidelberg), R. D. Gehrz and C. E. Woodward (University of Minnesota)
on 12 Jun 2008; 10:36 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Jan-Uwe Ness (Jan-Uwe.Ness@asu.edu)
Subjects: X-ray, Cataclysmic Variable, Nova, Transient
A second XMM-Newton observation of the nova V2491 Cyg was obtained on 2008 May 30.3, 49.6 days after the recent outburst and 10 days after an earlier one obtained on day 39.9 (Ness et al., ATel #1561). The exposure time in the Reflection Grating Spectrometers (RGS) was 29.8ksec, and the average count rate in the RGS1 was 2.7 counts per second (c/s). The light curve extracted from the RGS1 is less variable than during the first observation. The spectrum is that of a bright SSS (hot white dwarf atmosphere), with continuous emission ranging from 14Ã
and peaking at 23Ã
The shape of the continuum has changed, and exhibits less emission in the peak relative to the soft and hard wings. The continuum shortward of 17Ã
is also flatter than in the first observation, which might be a result of reduced absorption by the OVII ionization edge at 739.3eV (16.77Ã
). The relatively brighter continuum at longer wavelengths can be explained by a reduction in circumstellar absorption. The absorption lines show similar profiles and shifts to those reported by Ness et al. (ATel #1561), though the Ne lines appear weaker than before.
We thank the Science Operations Center for efficient scheduling of the XMM-Newton observation. XMM-Newton is an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.