Near-IR period-luminosity relations for pulsating stars in [Omega] Centauri (NGC 5139)
<i>Aims. <i/>The globular cluster <i>ω<i/> Centauri (NGC 5139) hosts hundreds of pulsating variable stars of different types, thus representing a treasure trove for studies of their corresponding period-luminosity (PL) relations. Our goal in this study is to obtain the PL rel...
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| Hauptverfasser: | , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
24 August 2017
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| In: |
Astronomy and astrophysics
Year: 2017, Jahrgang: 604, Pages: A120 |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/201630102 |
| Online-Zugang: | Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1051/0004-6361/201630102
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| Verfasserangaben: | C. Navarrete, M. Catelan, R. Contreras Ramos, J. Alonso-García, F. Gran, I. Dékány, and D. Minniti |
| Zusammenfassung: | <i>Aims. <i/>The globular cluster <i>ω<i/> Centauri (NGC 5139) hosts hundreds of pulsating variable stars of different types, thus representing a treasure trove for studies of their corresponding period-luminosity (PL) relations. Our goal in this study is to obtain the PL relations for RR Lyrae and SX Phoenicis stars in the field of the cluster, based on high-quality, well-sampled light curves in the near-infrared (IR).<i>Methods. <i/>Observations were carried out using the VISTA InfraRed CAMera (VIRCAM) mounted on the Visible and Infrared Survey Telescope for Astronomy (VISTA). A total of 42 epochs in <i>J<i/> and 100 epochs in <i>K<i/><sub>S<sub/> were obtained, spanning 352 days. Point-spread function photometry was performed using DoPhot and DAOPHOT crowded-field photometry packages in the outer and inner regions of the cluster, respectively.<i>Results. <i/>Based on the comprehensive catalog of near-IR light curves thus secured, PL relations were obtained for the different types of pulsators in the cluster, both in the <i>J<i/> and <i>K<i/><sub>S<sub/> bands. This includes the first PL relations in the near-IR for fundamental-mode SX Phoenicis stars. The near-IR magnitudes and periods of Type II Cepheids and RR Lyrae stars were used to derive an updated true distance modulus to the cluster, with a resulting value of (<i>m<i/> − <i>M<i/>)<sub>0<sub/> = 13.708 ± 0.035 ± 0.10 mag, where the error bars correspond to the adopted statistical and systematic errors, respectively. Adding the errors in quadrature, this is equivalent to a heliocentric distance of 5.52 ± 0.27 kpc. |
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| Beschreibung: | Im Titel ist Omega als griechischer Buchstabe dargestellt Gesehen am 18.10.2017 |
| Beschreibung: | Online Resource |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/201630102 |