Young stellar population in the star-forming complex Sh2-252

Abstract

We present the preliminary results of our multi-wavelength analyses of the young stellar population associated with the star forming complex Sh2-252. The NIR and MIR data sets from 2MASS and Spitzer-IRAC, MIPS identified 131 Class I, 400 Class II sources and a slitless spectroscopic survey detected 61 Hα emission line stars. The spatial distribution of these YSOs shows that majority of them are concentrated within the sub-regions Sh2-252 A, C and E. The optical CMD and SED analyses show that these YSOs show an age spread of ∼ 5 Myr and a mass range of 0.3 M⊙ - 2.5 M⊙. The CMD and SED analyses as well as the Class I/Class II fraction show that the sub-regions have a median age of ∼ 2-3 Myr, suggesting same evolutionary status for them. We report an enhanced concentration of Class I sources having a median age of ∼ 0.5 Myr between the ionization fronts of Sh2-252 and Sh2-252A. We presume that the combined expansion process of these two &hii; regions in opposite directions has triggered the new star formation within the collected material between them.