A new HST view of the prototypical giant H II region NGC604 in M33

BARBA, R; MAIZ APELLANIZ, J; PEREZ, E; RUBIO, M; BOLATTO, A; FARIÑA, C; BOSCH, G

Valparaiso, Chile

Congreso; VI Reunion Anual Sociedad Chilena de Astronomia; 2007

Sociedad Chilena de Astronomia

NGC 604 is, together with 30 Doradus, the extragalactic prototype of giant H II region. Its stellar content, mass (˜200 O+WR stars, ˜10^5), age (˜3.5 Ma), proximity (840 kpc), and low foreground extinction (E(B-V)< 0.1), make it an ideal object to study the massive stellar population of a scaled OB association, its interaction with the surrounding medium, and the effects caused by the strong differential extinction. We observed NGC 604 using HST/ACS and NICMOS instruments. The observations presented here are part of a multiwavelenghth study from the FUV to the millimetric regime. These data allow us to determine the NIR properties of the central scaled OB association and to identify an embedded very-young stellar population hidden inside the dust clouds in the southern part of the nebula, as well as a set of red supergiant stars. Our final goal is to analyze in detail a well-resolved giant H II region in order to understand the properties of similar but unresolved objects located at cosmological distances.