Age Determination of VVV Clusters from 5 Million Monte Carlo Simulations
Abstract
The most accurate method of age determination for resolved or partially resolved stellar clusters is based on color-magnitude diagrams (CMD). However, when the main sequence turnoff is not available or clearly identifiable, the age determined by isochrone fitting is affected by large errors. We used the MASSCLEAN package to perform 4 million Monte Carlo simulations in order to generate realistic looking CMDs. They mimic the observational photometric errors, and show the density of stars in the CMD plane. We use these CMD templates to analyze the newly discovered stellar clusters/cluster candidates from the Vista Variables in the Via Lactea (VVV) Survey. Since the majority of the new VVV clusters are low mass, the upper end of the stellar mass distribution is affected by stochastic fluctuations, which generates a large gap in the infrared CMD. We explore this gap in the J and K_s bands by performing 1 million Monte Carlo simulations. Combining the traditional isochrone fitting, CMD templates, and the magnitude distribution with respect to the infrared gap we were able to put better constrains on age, distance, and extinction for 7 VVV clusters. This material is based upon work supported by the National Science Foundation under Grant No. 0607497 and 1009550.
- Publication:
-
American Astronomical Society Meeting Abstracts #221
- Pub Date:
- January 2013
- Bibcode:
- 2013AAS...22125033P