Star Formation in M 33 (HerM33es)

¹ IRAM, Av. Divina Pastora 7, Nucleo Central, 18012 Granada, Spain
² Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA
³ Observatoire de Bordeaux, OASU, UMR 5804, CNRS/INSU, 33270 Floirac, France
⁴ IRAM, 300 rue de la Piscine, 38406 St. Martin d’ Hères, France
⁵ Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
⁶ Dept. Física Teórica y del Cosmos, Universidad de Granada, Spain

Abstract

Within the key project “Herschel M 33 extended survey” (HerM33es), we are studying the physical and chemical processes driving star formation and galactic evolution in the nearby galaxy M 33, combining the study of local conditions affecting individual star formation with properties only becoming apparent on global scales. Here, we present recent results obtained by the HerM33es team. Combining Spitzer and Herschel data ranging from 3.6 μm to 500μm, along with H i, Hα, and GALEX UV data, we have studied the dust at high spatial resolutions of 150 pc, providing estimators of the total infrared (TIR) brightness and of the star formation rate. While the temperature of the warm dust at high brightness is driven by young massive stars, evolved stellar populations appear to drive the temperature of the cold dust. Plane-parallel models of photon dominated regions (PDRs) fail to reproduce fully the [C ii], [O i], and CO maps obtained in a first spectroscopic study of one 2′ × 2′ subregion of M 33, located on the inner, northern spiral arm and encompassing the H ii region BCLMP 302.