The Herschel Key Programme CHESS : The case of the intermediate-mass protocluster OMC-2 FIR 4

Séminaire IPAG de Ana Sepulcre (IPAG), jeudi 6 décembre 2012 à 11h00, IPAG seminar room

Broadband spectral surveys of star-forming regions offer a rich view of their physical, chemical and dynamical structure and evolution. Thanks to the Herschel guaranteed time key programme CHESS, we now have in our hands line-rich spectra of a selected sample of objects representing different aspects of the star formation process. These were observed with the HIFI spectrograph on-board the Herschel satellite, and cover most of the frequencies between 480 and 1900 GHz.

I will first present an overview of the CHESS key program, and then focus on the case of OMC-2 FIR 4, an intermediate-mass protocluster, for which we also have complementary data observed at millimetre wavelengths with the IRAM 30-m telescope and the Plateau de Bure Interferometer. The ensemble of spectral data evidences the complex and clumpy nature of this region, where multiple cores, chemical differentiation, interactions with external molecular outflows, and ionised regions coexist within an area of only 0.05 pc.