On the Impact of Helium Content on the RR Lyrae Distance Scale

dc.contributor.authorMarconi, M.
dc.contributor.authorBono, G.
dc.contributor.authorPietrinferni, A.
dc.contributor.authorBraga, V.F.
dc.contributor.authorCastellani, M.
dc.contributor.authorStellingwerf, R.F.
dc.date.accessioned2019-12-04T17:53:03Z
dc.date.available2019-12-04T17:53:03Z
dc.date.issued2018-09
dc.descriptionIndexación: Scopus.es
dc.description.abstractWe constructed new sets of He-enhanced (Y = 0.30, Y = 0.40) nonlinear, time-dependent convective hydrodynamical models of RR Lyrae (RRL) stars covering a broad range in metal abundances (Z = 0.0001-0.02). The increase in He content from the canonical value (Y = 0.245) to Y = 0.30-0.40 causes a simultaneous increase in stellar luminosity and in pulsation period. To investigate the dependence of the RRL distance scale on the He abundance, we computed new optical (RI) and near-infrared (JHK) Period-luminosity-metallicity-helium relations. Interestingly enough, the increase in He content causes a minimal change in the coefficients of both period and metallicity terms, since canonical and He-enhanced models obey similar PLZ relations. On the contrary, the classical B-And V-band mean magnitude metallicity relations and the R-band PLZ relation display a significant dependence on the He content. The He-enhanced models are, at fixed metal content, 0.2-0.5 mag brighter than canonical ones. This variation is only marginally affected by evolutionary effects. The quoted distance diagnostics once calibrated with trigonometric parallaxes (Gaia) will provide the opportunity to estimate the He content of field and cluster RRLs. Moreover, the use of either spectroscopic or photometric metal abundances will pave the way to new empirical constraints on the universality of the helium-To-metal enrichment ratio in old (t10 Gyr) stellar tracers. © 2018. The American Astronomical Society. All rights reserved.es
dc.description.urihttps://iopscience.iop.org/article/10.3847/2041-8213/aada17
dc.identifier.citationAstrophysical Journal Letters, 864(1), art. no. L13.es
dc.identifier.issn2041-8205
dc.identifier.otherDOI: 10.3847/2041-8213/aada17
dc.identifier.urihttp://repositorio.unab.cl/xmlui/handle/ria/11121
dc.language.isoenes
dc.publisherInstitute of Physics Publishinges
dc.subjectEvolution-starses
dc.subjectHorizontal-branch-starses
dc.subjectOscillations-starses
dc.subjectRR Lyraees
dc.subjectStarses
dc.subjectVariableses
dc.titleOn the Impact of Helium Content on the RR Lyrae Distance Scalees
dc.typeArtículoes
Archivos
Bloque original
Mostrando 1 - 1 de 1
Cargando...
Miniatura
Nombre:
Marconi_On_the_Impact_of_Helium.pdf
Tamaño:
463.89 KB
Formato:
Adobe Portable Document Format
Descripción:
TEXTO COMPLETO EN INGLES
Bloque de licencias
Mostrando 1 - 1 de 1
No hay miniatura disponible
Nombre:
license.txt
Tamaño:
1.71 KB
Formato:
Item-specific license agreed upon to submission
Descripción: