Abstract Details
| Name: Debdutta Paul Affiliation: Tata Institute of Fundamental Research Conference ID: ASI2015_621 Title : Far-infrared spectroscopy of Orion protostars with Herschel/PACS: Protostellar evolution in diverse environments Authors and Co-Authors : Manoj Puravankara, Tata Institute of Fundamental Research Abstract Type : Poster Abstract Category : Stars, The Milky Way Galaxy and its neighbours Abstract : The early protostellar evolution is driven by the balance between in-fall, accretion and outflows, processes that can heat up the surrounding gas up to a few thousands Kelvin. The important cooling lines of the warm and hot circumstellar gas lie in the infrared wavelength range. We have obtained 50 to 200 micron spectra of some 30 protostars in the Orion molecular clouds as part of the Herschel key program the Herschel Protostar Survey (HOPS). Our sample of protostars span a large range in luminosities (1 - 300 L_sun) and evolutionary stages (Class 0 & I and Flat spectrum) and are located in vastly different environments; it is the largest sample far-infrared spectra of protostars from a single star forming region to date. We have successfully developed a semi-automated algorithm for identifying spectral lines in the far-IR spectra. We have analyzed rotational transitions of CO, ortho and para-H2O lines, OH lines and atomic forbidden lines ([OI]) to constrain the excitation conditions in the emitting gas. We searched for correlations between the estimated physical properties of the emitting gas and the protostellar properties to identify the processes responsible for the heating of the warm (~300 K) and hot (~1000 K) gas surrounding protostars. We will present the results of this statistical study and discuss their implications for our understanding of the earliest phase of star formation. |