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dc.contributor.authorMontgomery, M.H.en_US
dc.contributor.authorHermes, J.J.en_US
dc.contributor.authorWinget, D.E.en_US
dc.contributor.authorDunlap, B.H.en_US
dc.contributor.authorBell, K.J.en_US
dc.date.accessioned2021-03-11T17:46:46Z
dc.date.available2021-03-11T17:46:46Z
dc.identifier.citationM.H. Montgomery, J.J. Hermes, D.E. Winget, B.H. Dunlap, K.J. Bell. "Limits on Mode Coherence in Pulsating DA White Dwarfs Due to a Nonstatic Convection Zone." The Astrophysical Journal, Volume 890, Issue 1, pp. 11 - 11. https://doi.org/10.3847/1538-4357/ab6a0e
dc.identifier.issn1538-4357
dc.identifier.urihttps://hdl.handle.net/2144/42244
dc.description.abstractThe standard theory of pulsations deals with the frequencies and growth rates of infinitesimal perturbations in a stellar model. Modes that are calculated to be linearly driven should increase their amplitudes exponentially with time; the fact that nearly constant amplitudes are usually observed is evidence that nonlinear mechanisms inhibit the growth of finite-amplitude pulsations. Models predict that the mass of convection zones in pulsating hydrogen-atmosphere (DAV) white dwarfs is very sensitive to temperature (i.e., M_CZ∝T_eff^-90), leading to the possibility that even low-amplitude pulsators may experience significant nonlinear effects. In particular, the outer turning point of finite-amplitude g-mode pulsations can vary with the local surface temperature, producing a reflected wave that is out of phase with what is required for a standing wave. This can lead to a lack of coherence of the mode and a reduction in its global amplitude. In this paper we show that (1) whether a mode is calculated to propagate to the base of the convection zone is an accurate predictor of its width in the Fourier spectrum, (2) the phase shifts produced by reflection from the outer turning point are large enough to produce significant damping, and (3) amplitudes and periods are predicted to increase from the blue edge to the middle of the instability strip, and subsequently decrease as the red edge is approached. This amplitude decrease is in agreement with the observational data while the period decrease has not yet been systematically studied.en_US
dc.format.extentp. 11en_US
dc.language.isoen_US
dc.publisherAmerican Astronomical Societyen_US
dc.relation.ispartofThe Astrophysical Journal
dc.rights© 2020. The American Astronomical Society. All rights reserved.en_US
dc.subjectAstronomical and space sciencesen_US
dc.subjectAtomic, molecular, nuclear, particle and plasma physicsen_US
dc.subjectPhysical chemistry (incl. structural)en_US
dc.subjectAstronomy & astrophysicsen_US
dc.titleLimits on mode coherence in pulsating DA white dwarfs due to a nonstatic convection zoneen_US
dc.typeArticleen_US
dc.description.versionPublished versionen_US
dc.identifier.doi10.3847/1538-4357/ab6a0e
pubs.elements-sourcecrossrefen_US
pubs.notesEmbargo: Not knownen_US
pubs.organisational-groupBoston Universityen_US
pubs.organisational-groupBoston University, College of Arts & Sciencesen_US
pubs.organisational-groupBoston University, College of Arts & Sciences, Department of Astronomyen_US
pubs.publication-statusPublished onlineen_US
dc.date.online2020-02-07
dc.identifier.mycv554245


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