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Article: The eclipsing radio emission of the precataclysmic binary V471 tauri

TitleThe eclipsing radio emission of the precataclysmic binary V471 tauri
Authors
KeywordsBinaries: Eclipsing
Radio Continuum: Stars
Stars: Individual (V471 Tauri)
Stars: Magnetic Fields
White Dwarfs
Issue Date1996
PublisherInstitute of Physics Publishing Ltd. The Journal's web site is located at http://iopscience.iop.org/2041-8205
Citation
Astrophysical Journal Letters, 1996, v. 461 n. 2 PART I, p. 1009-1015 How to Cite?
AbstractWe present strong evidence confirming the presence of eclipses in the centimeter radio emission of the eclipsing binary V471 Tau, comprising a K2 dwarf and a white dwarf. In observations spanning two complete orbital periods, we detected one eclipse per orbit: in all, we observed one near-complete radio eclipse, the ingress phase of two other radio eclipses, and the egress phase of yet another radio eclipse. The minimum of the observed near-complete radio eclipse is centered at the orbital phase φ = 0 when the white dwarf is eclipsed and directly behind the K dwarf, and it has a full width of Δφ ≈ 3; by comparison, the optical eclipse of the white dwarf occupies only Δφ = 0.066. Inside eclipse, the total flux density of V471 Tau falls to a level ∼20% of that outside eclipse, implying that a large fraction of the radio emission originates from the region between the two stars. Outside eclipse, the radio emission varies slowly and follows, in large part, the same phase dependence over the two observed orbits (separated by one orbit). This suggests that much of the modulation observed outside eclipse may be due to an apparent change in the observed radiation pattern of the source with orbital revolution, rather than intrinsic variability in the radio emision process. From the data, we place constraints on the physical parameters of both the occulter and the occulted radio source; we find that the radio source is most probably radiating by nonthermal gyrosynchrotron emission. We favor a model where the radio-emitting electrons are accelerated by the interaction (collision) between the magnetospheres of the K dwarf and the white dwarf. This region of interaction is likely to be located very close to the surface of the white dwarf, leading naturally to a picture where the radio emission originates from large magnetic structures associated with the K dwarf. Such a model can qualitatively explain many of the features observed in the radio light curve. The proposed magnetic structures may provide the means by which mass is transferred from the K dwarf to the white dwarf, accounting partly or wholly for the inferred accretion of the white dwarf. © 1996. The American Astronomical Society. All rights reserved.
Persistent Identifierhttp://hdl.handle.net/10722/174949
ISSN
2015 Impact Factor: 5.487
2015 SCImago Journal Rankings: 3.369
References

 

DC FieldValueLanguage
dc.contributor.authorLim, Jen_US
dc.contributor.authorWhite, SMen_US
dc.contributor.authorCully, SLen_US
dc.date.accessioned2012-11-26T08:48:19Z-
dc.date.available2012-11-26T08:48:19Z-
dc.date.issued1996en_US
dc.identifier.citationAstrophysical Journal Letters, 1996, v. 461 n. 2 PART I, p. 1009-1015en_US
dc.identifier.issn2041-8205en_US
dc.identifier.urihttp://hdl.handle.net/10722/174949-
dc.description.abstractWe present strong evidence confirming the presence of eclipses in the centimeter radio emission of the eclipsing binary V471 Tau, comprising a K2 dwarf and a white dwarf. In observations spanning two complete orbital periods, we detected one eclipse per orbit: in all, we observed one near-complete radio eclipse, the ingress phase of two other radio eclipses, and the egress phase of yet another radio eclipse. The minimum of the observed near-complete radio eclipse is centered at the orbital phase φ = 0 when the white dwarf is eclipsed and directly behind the K dwarf, and it has a full width of Δφ ≈ 3; by comparison, the optical eclipse of the white dwarf occupies only Δφ = 0.066. Inside eclipse, the total flux density of V471 Tau falls to a level ∼20% of that outside eclipse, implying that a large fraction of the radio emission originates from the region between the two stars. Outside eclipse, the radio emission varies slowly and follows, in large part, the same phase dependence over the two observed orbits (separated by one orbit). This suggests that much of the modulation observed outside eclipse may be due to an apparent change in the observed radiation pattern of the source with orbital revolution, rather than intrinsic variability in the radio emision process. From the data, we place constraints on the physical parameters of both the occulter and the occulted radio source; we find that the radio source is most probably radiating by nonthermal gyrosynchrotron emission. We favor a model where the radio-emitting electrons are accelerated by the interaction (collision) between the magnetospheres of the K dwarf and the white dwarf. This region of interaction is likely to be located very close to the surface of the white dwarf, leading naturally to a picture where the radio emission originates from large magnetic structures associated with the K dwarf. Such a model can qualitatively explain many of the features observed in the radio light curve. The proposed magnetic structures may provide the means by which mass is transferred from the K dwarf to the white dwarf, accounting partly or wholly for the inferred accretion of the white dwarf. © 1996. The American Astronomical Society. All rights reserved.en_US
dc.languageengen_US
dc.publisherInstitute of Physics Publishing Ltd. The Journal's web site is located at http://iopscience.iop.org/2041-8205en_US
dc.relation.ispartofAstrophysical Journal Lettersen_US
dc.subjectBinaries: Eclipsingen_US
dc.subjectRadio Continuum: Starsen_US
dc.subjectStars: Individual (V471 Tauri)en_US
dc.subjectStars: Magnetic Fieldsen_US
dc.subjectWhite Dwarfsen_US
dc.titleThe eclipsing radio emission of the precataclysmic binary V471 taurien_US
dc.typeArticleen_US
dc.identifier.emailLim, J: jjlim@hku.hken_US
dc.identifier.authorityLim, J=rp00745en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.scopuseid_2-s2.0-21344474069en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-21344474069&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume461en_US
dc.identifier.issue2 PART Ien_US
dc.identifier.spage1009en_US
dc.identifier.epage1015en_US
dc.publisher.placeUnited Kingdomen_US
dc.identifier.scopusauthoridLim, J=7403453870en_US
dc.identifier.scopusauthoridWhite, SM=7404079906en_US
dc.identifier.scopusauthoridCully, SL=6602484140en_US

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