A 500-1900 GHz Spectral Survey of the Orion South Star Forming Region from the Herschel Space Observatory

Abstract

We will present initial results from a spectral survey toward Orion-S, taken by the HIFI instrument aboard the Herschel space telescope, in which we detect more than 800 spectral lines with S/N > 3 sigma originating from 47 different molecular and atomic species as well as a number of unidentified lines. Focusing on the transitions with S/N > 5 sigma we fit Gaussian line profiles to each of the observed transitions and have performed rotation/population diagram analysis for all the species for which we observed multiple transitions. This analysis provides us with the physical conditions, shows the presence of both warm (100 K) and cold (30 K) regions. A combination of population diagram analysis and the actual Local Thermodynamic Equilibrium modeling of the line profiles make us confident in the results of the molecular abundances, temperature, and other physical conditions in these two regions.