On the nature of SW Sex

Dhillon, V. S.; Marsh, T. R.; Jones, D. H. P.

doi:10.1093/mnras/291.4.694

Cited by 30 publications

(37 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…7) reveals more that the HeI 6678 line is double-peaked. We found also weak two-peaked emission lines of HeI in previous spectra of SW Sex stars: HeI 4471 and HeI 4921 of SW Sex (Dhillon et al (1997); HeI 5785 and HeI 6678 of SW Sex at phases 0.75−0.95 ( Fig. 7 in Groot et al 2011), weak HeI lines of UU Aqr (Hoard et al 1998), and HeI 6678 of AQ Men (Schmidtobreick et al 2008).…”

Section: Analysis Of the Spectral Data And Sw Sex Classification Of Jsupporting

confidence: 73%

“…3) compared with that of the secondary component, and the disk eclipse is total. But the disk of J2256 has a relative radius R d ∼ (0.6−0.7)ξ that is similar to those of two other SW Sex stars: R d > 0.6L1 for SW Sex (Dhillon et al 1997) and R d = 0.8L1 for DW UMa (Dhillon et al 2013). The obtained value β d ∼ 2−4…”

Section: Notesmentioning

confidence: 66%

“…7 in Groot et al 2011), weak HeI lines of UU Aqr (Hoard et al 1998), and HeI 6678 of AQ Men (Schmidtobreick et al 2008). Dhillon et al (1997Dhillon et al ( , 2013 supposed that the dominance of the single-peaked line emission from the hot spot over the weak double-peaked disk emission leads to the strange single-peaked lines of the SW Sex-type spectra and their radial velocity curves following the motion of the bright spot. The different amplitudes of the radial velocities of the different emission lines are another confirmation of this conclusion (Tovmassian et al 2014).…”

Section: Analysis Of the Spectral Data And Sw Sex Classification Of Jmentioning

confidence: 93%

See 2 more Smart Citations

2MASS J22560844+5954299: the newly discovered cataclysmic star with the deepest eclipse

Kjurkchieva

Khruzina

Dimitrov

et al. 2015

A&A

View full text Add to dashboard Cite

Context. The SW Sex stars are assumed to represent a distinguished stage in cataclysmic variable (CV) evolution, making it especially important to study them. Aims. We discovered a new cataclysmic star and carried out prolonged and precise photometric observations, as well as mediumresolution spectral observations. Modelling these data allowed us to determine the physical parameters and to establish its peculiarities. Methods. To obtain a light curve solution we used model whose emission sources are a white dwarf surrounded by an accretion disk with a hot spot, a gaseous stream near the disk's lateral side, and a secondary star filling its Roche lobe. The obtained physical parameters are compared with those of other SW Sex-subtype stars. Results. The newly discovered cataclysmic variable 2MASS J22560844+5954299 shows the deepest eclipse amongst the known nova-like stars. It was reproduced by totally covering a very luminous accretion disk by a red secondary component. The temperature distribution of the disk is flatter than that of steady-state disk. The target is unusual with the combination of a low mass ratio q ∼ 1.0 (considerably below the limit q = 1.2 of stable mass transfer of CVs) and an M-star secondary. The intensity of the observed three emission lines, Hα, He 5875, and He 6678, sharply increases around phase 0.0, accompanied by a Doppler jump to the shorter wavelength. The absence of eclipses of the emission lines and their single-peaked profiles means that they originate mainly in a vertically extended hot-spot halo. The emission Hα line reveals S-wave wavelength shifts with semi-amplitude of around 210 km s −1 and phase lag of 0.03. Conclusions. The non-steady-state emission of the luminous accretion disk of 2MASS J22560844+5954299 was attributed to the low viscosity of the disk matter caused by its unusually high temperature. The star shows all spectral properties of an SW Sex variable apart from the 0.5 central absorption.

show abstract

Section: Analysis Of the Spectral Data And Sw Sex Classification Of Jsupporting

confidence: 73%

Section: Notesmentioning

confidence: 66%

Section: Analysis Of the Spectral Data And Sw Sex Classification Of Jmentioning

confidence: 93%

See 1 more Smart Citation

2MASS J22560844+5954299: the newly discovered cataclysmic star with the deepest eclipse

Kjurkchieva

Khruzina

Dimitrov

et al. 2015

A&A

View full text Add to dashboard Cite

show abstract

“…The emission lines of J0644 are significantly narrower than SW Sex. Dhillon et al 1997 measured a FWZI (full width at zero intensity) of 5700 km s −1 for He II in SW Sex which compares to ∼2200 km s −1 for J0644.…”

Section: Discussionmentioning

confidence: 92%

Discovery of a bright eclipsing cataclysmic variable

Sing

Green

Howell³

et al. 2007

A&A

View full text Add to dashboard Cite

Aims. We report on the discovery of J0644+3344, a bright, deeply-eclipsing cataclysmic variable (CV) binary. Methods. Optical photometric and spectroscopic observations were obtained to determine the nature and characteristics of this CV. Results. Spectral signatures of both binary components and an accretion disk can be seen at optical wavelengths. The optical spectrum shows broad H I, He I, and He II accretion disk emission lines with deep narrow absorption components from H I, He I, Mg II, and Ca II. The absorption lines are seen throughout the orbital period, disappearing only during primary eclipse. These absorption lines are either the result of an optically-thick inner accretion disk or from the photosphere of the primary star. Radial velocity measurements show that the H I, He I, and Mg II absorption lines phase with the primary star, while weak absorption features in the continuum, between Hα and Hβ, phase with the secondary star. Radial velocity solutions give a 150 ± 4 km s −1 semi-amplitude for the primary star and 192.8 ± 5.6 km s −1 for the secondary, resulting in a primary to secondary mass ratio of q = 1.285. The individual stellar masses are 0.63−0.69 M for the primary and 0.49−0.54 M for the secondary, with the uncertainty largely due to the inclination. Conclusions. The bright eclipsing nature of this binary has helped provide masses for both components with an accuracy rarely achieved for CVs. This binary most closely resembles a nova-like UX UMa or SW Sex type of CV. J0644+3344, however, has a longer orbital period than most UX UMa or SW Sex stars. Assuming an evolution toward shorter orbital periods, J0644+3344 is therefore likely to be a young interacting binary. The secondary star is consistent with the size and spectral type of a K8 star, but has the mass of a M0.

show abstract

“…We will leave the details of this hypothetical process open for the moment, except for noting that some of the orbital phase-dependent anomalies seen in the SW Sex stars may be related to material accumulating just outside the orbit. In the model by Horne (1999), for example, these anomalies are explained in terms of a magnetic "" propeller e †ect ÏÏ acting on (a part of) the accretion stream (but see Dhillon et al 1997, Groot et al 2000, and Hellier 2000 for alternative explanations of the origin of these line proÐles). The low velocity emission seen in AM CVn has been attributed explicitly to circumbinary material by Solheim & Sion (1994), on account of its stationarity and narrow width.…”

Section: Theoretical Picturementioning

confidence: 99%

Circumbinary Disks and Cataclysmic Variable Evolution

Spruit

Taam

2001

ApJ

View full text Add to dashboard Cite

The inÑuence of a circumbinary (CB) disk on the evolution of cataclysmic variable (CV) binary systems is investigated. We show that CB mass surface densities sufficient to inÑuence the evolution rate are plausibly provided by the outÑows observed in CVs, if the net e †ect of these winds is to deliver 10~4 to 10~3 of the mass transfer rate to the CB disk. The torque exerted by the CB disk provides a positive feedback between mass transfer rate and CB disk mass that can lead to mass transfer rates of D10~8 to 10~7 yr~1. This mechanism may be responsible for causing the range of variation of mass transfer M _ rates in CVs. In particular, it may explain rates inferred for the nova-like variables and the supersoft X-ray binary systems observed near the upper edge of the period gap (P D 3È4 hr), as well as the spread in mass transfer rates above and below the period gap. Consequences and the possible observability of such disks are discussed.

show abstract

On the nature of SW Sex

Cited by 30 publications

References 39 publications

2MASS J22560844+5954299: the newly discovered cataclysmic star with the deepest eclipse

2MASS J22560844+5954299: the newly discovered cataclysmic star with the deepest eclipse

Discovery of a bright eclipsing cataclysmic variable

Circumbinary Disks and Cataclysmic Variable Evolution

Contact Info

Product

Resources

About