Near-Infrared Observations of RR Lyrae Variables in Galactic Globular Clusters. I. The Case of M92
| Autor: | A. M. Piersimoni, M. Del Principe, Mauro Dolci, Giuseppe Bono, A. Di Paola, Marcella Marconi |
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| Jazyk: | angličtina |
| Rok vydání: | 2005 |
| Předmět: |
Physics
Settore FIS/05 Astrophysics::High Energy Astrophysical Phenomena Astrophysics (astro-ph) Near-infrared spectroscopy FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics RR Lyrae variable Light curve Red-giant branch Space and Planetary Science Globular cluster Cluster (physics) Astrophysics::Solar and Stellar Astrophysics Astrophysics::Galaxy Astrophysics |
| Popis: | We present near-infrared J,H, and K-band time series observations of the Galactic Globular Cluster (GGC) M92. On the basis of these data, we derived well-sampled light curves for eleven out of the seventeen cluster RR Lyrae variables, and in turn, accurate mean near-infrared (NIR) magnitudes. The comparison between predicted and empirical slopes of NIR Period-Luminosity (PL) relations indicates a very good agreement. Cluster distance determinations based on independent theoretical NIR $PL$ relations present uncertainties smaller than 5% and agree quite well with recent distance estimates based on different distance indicators. We also obtained accurate and deep NIR color-magnitude diagrams (CMDs) ranging from the tip of the Red Giant Branch (RGB) down to the Main Sequence Turn-Off. We detected the RGB bump and the NIR luminosities of this evolutionary feature are, within theoretical and empirical uncertainties, in good agreement with each other. Comment: 30 pages, 8 figures, accepted for pubblication on AJ |
| Databáze: | OpenAIRE |
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