Tomography of Polars

Schwope, A. D.

doi:10.1007/3-540-45339-3_10

Cited by 21 publications

(31 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Giving the striking similarity to line profile variability of other polars observed in high and low states (see the collection of Doppler maps in e.g. Schwope 2001, and references therein) the narrow line component can unequivocally be assigned to the secondary star. The Hα line has additional components, perhaps best visible in the first spectrum at phase 0.12.…”

Section: X-shooter Spectroscopy Of Ef Erimentioning

confidence: 66%

X-Shooting EF Eridani: further evidence for a massive white dwarf and a sub-stellar secondary

Schwope¹,

Christensen

2010

A&A

View full text Add to dashboard Cite

High resolution spectral observations of the polar EF Eridani obtained in a low state with X-Shooter revealed narrow emission lines from the irradiated secondary. The lines were most prominent in the near-IR Caii-triplet, the more intensive Hα line had additional emission likely originating from an accretion stream. The lines with a radial velocity amplitude, K 2 = 385 ± 4 km s −1 , serve as tracer of the otherwise unseen companion. The mass function implies a massive white dwarf with M wd > 0.65 M at 3σ confidence, and a short distance to the binary, d ∼ 111 pc (<145 pc at 3σ confidence). The spectral energy distribution from the UV to the IR together with the high mass ratio gives further strong evidence of EF Eri being a post period-minimum object with M 2 < 0.06 M .

show abstract

Section: X-shooter Spectroscopy Of Ef Erimentioning

confidence: 66%

X-Shooting EF Eridani: further evidence for a massive white dwarf and a sub-stellar secondary

Schwope¹,

Christensen

2010

A&A

View full text Add to dashboard Cite

show abstract

“…It is a common assumption that long-term changes of the accretion rate are related to star spots on the donor at the L 1 (King & Cannizzo 1998) and an attempt has been made to reconstruct a possible pattern of star spots from the accretion history of AM Her (Hessman et al 2000). While irradiation-induced structure is obvious in Doppler tomograms of the donors, these experiments have failed so far to make star spots visible (Schwope 2001). The main features of the X-ray light curve of a polar in a one-pole accretion geometry are exemplified in Fig.…”

Section: X-ray Light Curvesmentioning

confidence: 99%

X-rays from cataclysmic variables

Kuulkers

Norton

Schwope

et al. 2006

Compact Stellar X-Ray Sources

View full text Add to dashboard Cite

IntroductionCataclysmic Variables * (CVs) are a distinct class of interacting binaries, transferring mass from a donor star to a degenerate accretor, a white dwarf (WD). In all observational determinations, and as is required by theory for stable mass transfer, the donor star is of lower mass than the accretor.The majority of CVs have orbital periods, P orb , between 75 min and 8 h (see Ritter & Kolb 2003) and consist of Roche Lobe-filling main sequence donors and WDs. These are WD analogues of the low-mass X-ray binaries (LMXBs; see Chapter 1). In the period range 8 h-3 d the donors must have larger radii than dwarfs in order to fill their Roche Lobes and are therefore evolved subgiants. A few CVs are found with P orb ∼200 d, which require giant donors for them to be Lobe-filling. The absence of evolved CVs with periods ∼3 to ∼200 d is connected with the dynamical instability that results from an initial donor that had a mass larger than about 67% of that of the WD; such binaries will have experienced rapid mass transfer and shortened their periods during a common envelope phase. Beyond P orb ∼200 d, mass-transferring systems also exist. These constitute the symbiotic binaries (SBs) and are in general not Roche Lobe-filling, but instead consist of a WD orbiting in the wind of a supergiant, and are thus analogues of the high-mass X-ray binaries (see Chapter 1).At the short end of the period range a different kind of CV exists, i.e., in which the mass losing donors are themselves WDs; they are entirely deficient in hydrogen. These helium-transferring CVs are known, after the type star, as AM CVn stars and are observed to have P orb from 60 min down to at least as short as 10 min. They have evolved by passage through two common envelope phases, which leaves the cores of both of the component stars exposed.The CVs are divided into subtypes. These were originally based entirely on the behaviour seen in long-term optical light curves, but to this are now added more subtle parameters such as the presence of polarisation. In essence, a CV's gross behaviour is determined by the rate of mass transfer from the donor,Ṁ donor , and * See Hack & La Dous (1993) and Warner (1995) for comprehensive overviews.

show abstract

“…The spiral structure not only varies in strength but also in size and position in the disc (Boffin & Steeghs 2002). Also of interest are the maps of helium CVs like AM CVn, that allowed the authors to constrain the system parameters (Nelemans et al 2001) and GP Com, that showed a rather complicated structure in the bright spot emission (Morales-Rueda et al 2003), maps of IP Peg during quiescence possibly showing the presence of spiral structure , and maps of magnetic systems that allowed the authors to constrain the accretion geometry (Schwope 2001).…”

Section: Recent Results From Doppler Tomographymentioning

confidence: 99%

Doppler tomography of cataclysmic variables

Morales-Rueda

2004

Astron Nachr

View full text Add to dashboard Cite

Abstract. The study of cataclysmic variables (CVs), and in particular of the evolution of their accretion discs throughout their different brightness states, has benefited largely from the use of indirect imaging techniques. I report on the latest results obtained from Doppler tomography of CVs concentrating mainly on results published since the 2000 Astrotomography meeting in Brussels. Emphasis is given to the spiral structures found in the accretion discs of some CVs, to the evolution of these structures throughout quiescence and outburst, and to our search for them in more systems.

show abstract

Tomography of Polars

Cited by 21 publications

References 41 publications

X-Shooting EF Eridani: further evidence for a massive white dwarf and a sub-stellar secondary

X-Shooting EF Eridani: further evidence for a massive white dwarf and a sub-stellar secondary

X-rays from cataclysmic variables

Doppler tomography of cataclysmic variables

Contact Info

Product

Resources

About