Induced star formation in the HII region Sh2-54

J. VASQUEZ; C.E. CAPPA; S. CICHOWOLSKI; M. ORTEGA; G. ROMERO; M. RUBIO

Morelia

Simposio; XIII Reunión Regional Latino-Americana de la UAI; 2010

Unión Astronómica Internacional

Expanding HII regions surrounded by dense molecular shells are potentialsites for the formation of new stars. Two main mechanisms have been proposedfor the stellar formation process in the outer dense shells: the radiativelydriven implossion model (RDI) and the "collect and collapse" model. In thislast case, the shell becomes unstable and fragments, leading to theformation of massive stars.    Sh2-54 in an HII region of about 7 arcmin in size located atRA,Dec.(J2000)=(18:17:52.5, -11:40:58) at a distance of ~2.5 kpc. A number ofIRAS, Spitzer, and 2MASS point sources classified as YSO candidates arelocated in its environs. In this report, we carry out a morphological studyof the IR and radio counterparts of the HII region, focussing on theanalysis of the stellar formation activity in the region. For this pourpose,we take into account the interaction between the UV photons emitted by theexcitation sources and the molecular environment. Differents stellarformation mechanisms will be confronted to explain the star formationactivity in the region.