A Reanalysis of High Resolution XMM-Newton Data of V2491 Cyg Using Collisionally Ionized Hot Absorber Models
arXiv:1610.08440 · doi:10.1051/0004-6361/201629360
Abstract
We present a reanalysis of XMM-Newton Reflection Grating Spectrometer data of the classical nova V2491 Cyg obtained from two different pointings, 40 d and 50 d after outburst utilizing the SRON software SPEX version 2.05.04. We aim to model absorption components using hot collisionally ionized absorber models along with interstellar absorption (of gas and dust origin separately). We find blackbody temperatures in a range 61-91 eV for the continuum yielding a white dwarf mass of 1.15-1.3 M_sun. We derive two different hot absorber components with blueshifts yielding 2900-3800 km/s for the first (day 40) and 2600-3600 km/s for the second observation 50 days after outburst consistent with ejecta/wind speeds. The two collisionally ionized hot absorption components have temperatures kT_1 =1.0-3.6 keV and kT_2 =0.4-0.87 keV with rms velocities (sigma_v) 872 km/s and 56 km/s. These are consistent with shock temperatures in the X-ray wavelengths. V2491 Cyg shows signature of H-burning with underabundant carbon C/C_sun=0.3-0.5, and enhanced nitrogen N/N_sun=5-7 and oxygen O/O_sun=16-43. We find the equivalent hydrogen column density of the hot collisionally ionized absorbers in a range (0.6-18.0)x10^{23} cm^{-2} and (2.0-5.3)x10^{23} cm^{-2} on days 40 and 50 after outburst, respectively. Our fits yield the most adequate redchisq (range 1.8-2.9) up-to-date obtained for the modeling of high resolution X-ray data of V2491 Cyg. An additional photoionized absorber (third intrinsic absorber component) originating in the shell/ejecta improves the model fits with redchisq in a range 1.7-2.5, but shows only (1-0.1)% of the absorption by the collisionaly-ionized hot gas. Our analysis reveals a second blackbody component on day 50 with effective temperature 120-131 eV and effective radius about 10% of the WD which may indicate the onset of magnetic accretion.
12 pages, 7 figures, and 2 Tables, accepted for publication in A&A (main Journal). arXiv admin note: text overlap with arXiv:astro-ph/0410385 by other authors
References in corpus (11)
- X-Ray Emitting Blast Wave from the Recurrent Nova RS Ophiuchi
- The Super-Soft X-ray Phase of Nova RS Ophiuchi 2006
- X-ray Spectroscopy of the 2006 Outburst of RS Oph
- The SSS phase of RS Ophiuchi observed with Chandra and XMM-Newton I.: Data and preliminary Modeling
- NLTE model atmospheres for the hottest white dwarfs: Spectral analysis of the compact component in nova V4743 Sgr
- High-resolution X-ray spectroscopy of the evolving shock in the 2006 outburst of RS Ophiuchi
- The Morphology of the Expanding Ejecta of V2491 Cygni (2008 N.2)
- A NuSTAR observation of the fast symbiotic nova V745 Sco in outburst
- Pre-nova X-ray observations of V2491 Cyg (Nova Cyg 2008b)
- A phenomenological model for the X-ray spectrum of Nova V2491 Cygni
- XMM-Newton observations of Nova Sgr 1998