The VVV Survey RR Lyrae Population in the Galactic Center Region

Vista sencilla de ítem
dc.contributor.authorContreras Ramos, R.
dc.contributor.authorMinniti, D.
dc.contributor.authorGran, F.
dc.contributor.authorZoccali, M.
dc.contributor.authorAlonso-Garcia, J.
dc.contributor.authorHuijse, P.
dc.contributor.authorNavarro, M.G.
dc.contributor.authorRojas-Arriagada, A.
dc.contributor.authorValenti, E.
dc.date.accessioned2019-11-28T14:34:01Z
dc.date.available2019-11-28T14:34:01Z
dc.date.issued2018-08
dc.descriptionIndexación: Scopus.es
dc.descriptionWe gratefully acknowledge the use of data from the ESO Public Survey program ID 179.B-2002 taken with the VISTA telescope, and data products from the Cambridge Astronomical Survey Unit (CASU). Support for the authors is provided by the BASAL Center for Astrophysics and Associated Technologies (CATA) through grant PFB-06, and the Ministry for the Economy, Development, and Tourism, Programa Iniciativa Cientifica Milenio through grant IC120009, awarded to the Millennium Institute of Astrophysics (MAS). D.M. and M.Z. acknowledge support from FONDECYT Regular grants No. 1170121, and 1150345, respectively. P.H. acknowledges financial support from FONDECYT regular grant 1170305. F.G. acknowledge support from CONICYT-PCHA Doctorado Nacional 2017-21171485 and Proyecto Fondecyt Regular 1150345. J.A.-G. acknowledges support by FONDECYT Iniciacion 11150916. D.M. is also grateful for the hospitality of the Vatican Observatory. This research made use of Astropy, a community-developed core Python package for astronomy; Scikit-learn, NumPy, and matplotlib, a Python library for publication-quality graphics; and Aladin Sky Atlas, developed at CDS, Strasbourg Observatory, France, and TOPCAT.
dc.description.abstractDeep near-IR images from the VISTA Variables in the V a L ctea (VVV) Survey were used to search for RR Lyrae stars within 100 arcmin from the Galactic Center. A large sample of 960 RR Lyrae of type ab (RRab) stars were discovered. A catalog is presented featuring the positions, magnitudes, colors, periods, and amplitudes for the sample, in addition to estimated reddenings, distances, and metallicities, and measured individual relative proper motions. We use the reddening-corrected Wesenheit magnitudes, defined as WKs Ks 0.428 J Ks = - ( - ), in order to isolate bona fide RRL belonging to the Galaxy Center, finding that 30 RRab are foreground/background objects. We measure a range of extinctions from AKs 0.19 = to 1.75 mag for the RRab in this region, finding that large extinction is the main cause of the sample incompleteness. The mean period is P =0.5446±0.0025 days, yielding a mean metallicity of [Fe/H] =-1.30±0.01 (ς = 0.33) dex for the RRab sample in the Galactic Center region. The median distance for the sample is D =8.05±0.02 kpc. We measure the RRab surface density using the less reddened region sampled here, finding a density of 1000 RRab/sq deg at a projected Galactocentric distance RG =1.6 deg. Under simple assumptions, this implies a large total mass (M>109Me) for the old and metal-poor population contained inside RG. We also measure accurate relative proper motions, from which we derive tangential velocity dispersions of ςVl =125.0 and ςVb =124.1 km s-1 along the Galactic longitude and latitude coordinates, respectively. The fact that these quantities are similar indicate that the bulk rotation of the RRab population is negligible, and implies that this population is supported by velocity dispersion. In summary, there are two main conclusions of this study. First, the population as a whole is no different from the outer bulge RRab, predominantly a metal-poor component that is shifted with respect to the Oosterhoff type I population defined by the globular clusters in the halo. Second, the RRab sample, as representative of the old and metal-poor stellar population in the region, has high velocity dispersions and zero rotation, suggesting a formation via dissipational collapse. ©2018. The American Astronomical Society. All rights reserved.es
dc.description.urihttps://iopscience.iop.org/article/10.3847/1538-4357/aacf90
dc.identifier.citationAstrophysical Journal, 863(1), art. no. 79.es
dc.identifier.issn0004-637X
dc.identifier.otherDOI: 10.3847/1538-4357/aacf90
dc.identifier.urihttp://repositorio.unab.cl/xmlui/handle/ria/10876
dc.language.isoenes
dc.publisherInstitute of Physics Publishinges
dc.subjectCatalogses
dc.subjectGalaxy: bulgees
dc.subjectProper motionses
dc.subjectStars: variables: RR Lyraees
dc.subjectSurveyses
dc.titleThe VVV Survey RR Lyrae Population in the Galactic Center Regiones
dc.typeArtículoes
Archivos
Bloque original
Mostrando 1 - 1 de 1
Miniatura
Nombre:
Contreras_Ramos_The_VVV_Survey_RR.pdf
Tamaño:
16 MB
Formato:
Adobe Portable Document Format
Descripción:
TEXTO COMPLETO EN INGLES
Descargar
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:
Descargar
Colecciones
FCE - Artículos de Revista