to IAU
Symposium 241

# Abstract details

A comparison of $UBVRI$ photometry data of star forming regions in NGC 628 with a detailed grid of synthetic evolutionary models of stellar systems
Gusev, A.S., Sakhibov, F.Kh., & Smirnov, M.A.

Abstract
Interpretation of observed properties of young stellar population in NGC 628 is carried out on the basis of the comparison of the high resolution UBVRI photometry data of 127 $H_\alpha$ regions in the galaxy with the detailed grid of the synthetic evolutionary models of stellar systems. The detailed grid of evolutionary models includes 2 regimes of star formation (instantaneous burst and a constant star formation), whole range of IMF (slope and an upper mass limit) and age (from 1 Myr up to 100 Myrs). The chemical abundance of the star forming regions was determined from the independent observations. The solution of the reverse problem of finding of age, regime of star formation, IMF parameters, and dust absorption in the star forming regions is produced with the aid of a special regularizing deviation functional. Reddening estimations are correlated with galactocentric distances of star forming regions, in conformity with a chemical abundance radial gradient derived from independent observations. Ages of star formation complexes also show a trend as a function of chemical composition. There are three scales of star formation is found in the galaxy: 80, 200, and 500 pc.