8-12 juin, 2014


Validation of optimized population synthesis and investigation of isochrone consistency using Galactic globular clusters

Stephane Courteau (Queen's University)

S. Courteau, C. Barber, S. Hills, J. Roediger (1), R.P. Schiavon (2), T. von Hippel (3), A. Geller (4) [1. Queen's University; 2. LJMU; 3. ERAU; 4. Northwestern Univ.]

We present the first validation of population synthesis via nonlinear bound-constrained optimisation of stellar populations based upon optical spectra of mock stellar systems and observed Galactic Globular Clusters (GGCs). We demonstrate that optimized population synthesis provides a reliable empirical method to extract the relative mix of stellar evolutionary stages and the distribution of atmospheric parameters within unresolved stellar systems. For 24 GGCs, the contribution to integrated light by stars in various evolutionary stages as determined by our synthesis is in excellent agreement with expectations from deep HST/ACS colour magnitude diagrams. However, we caution about the consistency and reliability of fitting different stellar evolution models to various combinations of optical and near-IR photometry for any given stellar system.

Mode de présentation: 2014-06-09 13:45 (doit être confirmé par le SOC)