Uncloaking Globular Clusters in the Inner Galaxy.

Globular Clusters;Galaxy Evolution;Astronomy;Science;Astronomy and Astrophysics

Alonso Garc, JavierHeitsch, Fabian ;

University of Michigan

关键词: Globular Clusters;    Galaxy Evolution;    Astronomy;    Science;    Astronomy and Astrophysics;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/75831/jalonso_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

A serious limitation in the study of many globular clusters – especially those located towards the center of the Milky Way – has been the existence of large and differential extinction by foreground dust. In this thesis we present a well-defined and reasonably homogeneous photometric database for 25 of the brightest Galactic globular clusters located in the direction of the inner Galaxy. These data were obtained in the B, V, and I bands using the Magellan 6.5m telescope and the Hubble Space Telescope. We develop a new technique, using a non-parametric statistical approach to map the differential reddening in the individual cluster fields, and to produce cleaner, dereddened color magnitude diagrams for all the clusters in the database. Using these color-magnitude diagrams and the new α-enhanced Dartmouth stellar evolutionary models, we provide an analysis of the stellar populations of these clusters, and accurately determine their ages, distances, and reddenings. We find all the inner clusters in our sample to be old and formed in a short time spread, consistent with an old, fast forming spheroid scenario for the Galactic bulge.