Show simple item record

dc.contributor.authorKarl, C.
dc.contributor.authorHeber, U.
dc.contributor.authorNapiwotzki, R.
dc.contributor.authorDreizler, S.
dc.contributor.authorKoester, D.
dc.contributor.authorReid, I.N.
dc.date.accessioned2008-06-27T14:14:41Z
dc.date.available2008-06-27T14:14:41Z
dc.date.issued2005
dc.identifier.citationKarl , C , Heber , U , Napiwotzki , R , Dreizler , S , Koester , D & Reid , I N 2005 , Rotation Velocities of DA White Dwarfs with Convective Atmospheres . in In: Procs of the 14th European Workshop on White Dwarfs - ASP Conf Series 334 . Astronomical Society of the Pacific , pp. 241-244 .
dc.identifier.isbn1-58381-197-4
dc.identifier.isbn978-1-58381-268-6
dc.identifier.otherPURE: 166924
dc.identifier.otherPURE UUID: a8aac07e-c3d7-43e0-8ebb-d3f26f21a2ea
dc.identifier.otherdspace: 2299/2148
dc.identifier.urihttp://hdl.handle.net/2299/2148
dc.descriptionOriginal paper can be found at: http://www.astrosociety.org/pubs/cs/328.html Copyright ASP
dc.description.abstractThe sharp H® NLTE line cores of hydrogen rich (DA) white dwarfs allow their projected rotational velocities to be determined. High resolution optical spectra of 22 stars obtained with the Keck I telescope are matched by synthetic spectra computed from a grid of NLTE model atmospheres. We concentrate preferentially on hydrogen-rich white dwarfs with convective atmospheres, i.e. with Te® <14 000 K. Previous analyses found DA white dwarfs hotter than 14 000 K to be very slow rotators and rarely show any spectroscopically detectable rotation. For 19 of our program stars we were able to derive projected rotational velocities or upper limits. Combining our results with those from two similar studies (Heber et al 1997, paper I and Koester et al. 1998, paper II), we have obtained information of 56 DA white dwarfs. The fraction of rotating DA white dwarfs whose line profiles can be matched for a vanishing projected rotation velocities is high for hot white dwarfs with radiative atmospheres (25 out of 28) with upper limits ranging from 1 kms¡1 to 24 kms¡1, whereas amongst the cool white dwarfs with presumably convective atmospheres only for a few stars (8 out of 22) no additional line broadening has to be invoked to explain their observed H® line profiles resulting in upper limits to v sin i of 7 kms¡1 to 35 kms¡1 .en
dc.language.isoeng
dc.publisherAstronomical Society of the Pacific
dc.relation.ispartofIn: Procs of the 14th European Workshop on White Dwarfs - ASP Conf Series 334
dc.titleRotation Velocities of DA White Dwarfs with Convective Atmospheresen
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.contributor.institutionSchool of Physics, Engineering & Computer Science
dc.contributor.institutionDepartment of Physics, Astronomy and Mathematics
dc.contributor.institutionCentre for Astrophysics Research
rioxxterms.typeOther
herts.preservation.rarelyaccessedtrue


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record