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Mapping Differential Reddening in the Inner Galactic Globular Cluster System

Alonso-García, Javier and Mateo, Mario and Sen, Bodhisattva and Banerjee, Moulinath and von Braun, Kaspar (2011) Mapping Differential Reddening in the Inner Galactic Globular Cluster System. Astronomical Journal, 141 (5). Art. No. 146. ISSN 0004-6256.

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A serious limitation in the study of many globular clusters—especially those located near the Galactic center—has been the existence of large and differential extinction by foreground dust. In a series of papers, we intend to map the differential extinction and remove its effects, using a new dereddening technique, in a sample of clusters in the direction of the inner Galaxy, observed using the Magellan 6.5 m telescope and the Hubble Space Telescope. These observations and their analysis will let us produce high-quality color-magnitude diagrams of these poorly studied clusters that will allow us to determine these clusters' relative ages, distances, and chemistry and to address important questions about the formation and the evolution of the inner Galaxy. We also intend to use the maps of the differential extinction to sample and characterize the interstellar medium along the numerous low-latitude lines of sight where the clusters in our sample lie. In this first paper, we describe in detail our dereddening method along with the powerful statistics tools that allow us to apply it, and we show the kind of results that we can expect, applying the method to M62, one of the clusters in our sample. The width of the main sequence and lower red giant branch narrows by a factor of two after applying our dereddening technique, which will significantly help to constrain the age, distance, and metallicity of the cluster.

Item Type:Article
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URLURL TypeDescription DOIArticle
Alonso-García, Javier0000-0003-3496-3772
von Braun, Kaspar0000-0002-5823-4630
Additional Information:© 2011 The American Astronomical Society. Received 2010 November 3; accepted 2011 January 22; published 2011 March 28. Based partly on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. This paper also includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. This work was supported by grants 0206081 from NSF and GO10573.01-A from STScI. STScI is operated by AURA under NASA contract NAS5-26555. Support for J.A. was also provided by MIDEPLAN’s Programa Inicativa Científica Milenio through grant P07-021-F, awarded to The Milky Way Millennium Nucleus.
Funding AgencyGrant Number
NASANAS 5-26555
MIDEPLAN’s Programa Inicativa Científica MilenioP07-021-F
Subject Keywords:dust, extinction; Galaxy: bulge; globular clusters: general; globular clusters: individual (NGC 6266, M62); methods: statistical
Issue or Number:5
Classification Code:PACS: 98.20.Gm; 98.38.Am; 98.35.Ln; 98.35.Ac; 98.35.Jk
Record Number:CaltechAUTHORS:20110503-095731144
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Official Citation:Mapping Differential Reddening in the Inner Galactic Globular Cluster System Javier Alonso-García et al. 2011 The Astronomical Journal 141 146
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:23529
Deposited By: Tony Diaz
Deposited On:03 May 2011 22:29
Last Modified:09 Mar 2020 13:18

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