Astron. Astrophys. Suppl. Ser. 138, 19-30
Evolutionary synthesis of simple stellar populations
Colours and indices
O.M. Kurth - U. Fritze - v. Alvensleben - K.J. Fricke
Send offprint request: O. Kurth
Universitätssternwarte Göttingen, Geismarlandstr. 11, 37083 Göttingen, Germany
Received March 16, 1998; accepted February 11, 1999
We construct evolutionary synthesis models for simple stellar populations using the evolutionary tracks from the Padova group (1993, 1994), theoretical colour calibrations from [Lejeune et al. (1997, 1998)] and fit functions for stellar atmospheric indices from [Worthey et al. (1994)].
A Monte-Carlo technique allows us to obtain a smooth time evolution of both broad band colours in UBVRIK and a series of stellar absorption features for Single Burst Stellar Populations (SSPs). We present colours and indices for SSPs with ages from yrs to yrs and metallicities [M/H]=-2.3, -1.7, -0.7, -0.4, 0.0 and 0.4.
Model colours and indices at an age of about a Hubble time are in good agreement with observed colours and indices of the Galactic and M 31 GCs.
Key words: Galaxy: globular cluster; open clusters galaxies: starclusters; M 31; evolution