Long, Knox S., Gänsicke, B. T. (Boris T.), Knigge, Christian, Froning, Cynthia S. and Monard, Berto (2009) The effect of a superoutburst on the white dwarf and disk of VW Hydri as observed with FUSE. The Astrophysical Journal, Vol.697 (No.2). pp. 1512-1528. doi:10.1088/0004-637X/697/2/1512 ISSN 0004-637X.

Research output not available from this repository.

Request-a-Copy directly from author or use local Library Get it For Me service.

Request Changes to record.

Abstract

We have used Far Ultraviolet Spectroscopic Explorer (FUSE) to obtain a series of 13 observations of the nearby dwarf nova VW Hyi that cover the period from the end of a superoutburst through the following normal outburst of the system. Here, we present the quiescent spectra taken after each outburst event. The spectra obtained during quiescence contain at least three components. The dominant component over most of the FUSE wavelength range is the white dwarf (WD), which cools following the superoutburst. The amount of cooling is dependent on the WD models utilized. For log g of 8.0, the temperature drops from 24,000 K just after the outburst to 20,000 K just before the normal outburst. For this model, and for a distance of 65 pc, the radius of the WD is approximately 8 x 10(8) cm and nu sin (i) is similar to 420 km s(-1). The fact that the derived radius is smaller than expected for a WD with log g = 8 suggests a higher gravity WD or that VW Hyi is somewhat further than its canonical distance of 65 pc. Either is possible given the current uncertainty (+/- 20 pc) in the distance to VW Hyi. Earlier suggestions that the WD photosphere show evidence of CNO processed material are confirmed, but our analysis also highlights the fact that significant issues remain in terms of analyzing the spectra of WDs in such unusual physical situations. The second component is relatively featureless and shows substantial modulation on the orbital (and just after outburst, the superhump) period. The second component is most likely associated with the hot spot where material from the secondary encounters the disk, rather than emission from the boundary layer region between the inner disk and WD. This second component fades about 10 days after the superoutburst. There is also a third component, clearly visible in terms of broad emission lines of C III lambda 977, N III lambda 991, and a combination of Ly beta and O VI..1032, 1038, which appears to be accompanied by a flat continuum. The strength of the emission lines, which are almost surely associated with the accretion disk, appears relatively constant for the duration of the observations.

Item Type:	Journal Article
Subjects:	Q Science > QB Astronomy
Divisions:	Faculty of Science, Engineering and Medicine > Science > Physics
Library of Congress Subject Headings (LCSH):	Double stars, Cataclysmic variable stars, Ultraviolet stars, Stars, New
Journal or Publication Title:	The Astrophysical Journal
Publisher:	Institute of Physics Publishing, Inc.
ISSN:	0004-637X
Official Date:	1 June 2009
Dates:	Date Event 1 June 2009 Published
Volume:	Vol.697
Number:	No.2
Number of Pages:	17
Page Range:	pp. 1512-1528
DOI:	10.1088/0004-637X/697/2/1512
Status:	Peer Reviewed
Publication Status:	Published
Access rights to Published version:	Restricted or Subscription Access
Funder:	United States. National Aeronautics and Space Administration (NASA)
Grant number:	NNG04GQ38G

Data sourced from Thomson Reuters' Web of Knowledge

Request changes or add full text files to a record

Repository staff actions (login required)

View Item