Odin observation of water in the IRAS 16293-2422 low-mass star forming region
2005 (English)In: Astrochemistry: Recent Successes and Current Challenges: Proceedings of the 231st Symposium of the International Astronomical Union held in Pacific Grove, California, USA, August 29-September 2, 2005, 2005, Vol. 235, 227P- p.Conference paper (Other academic)
We present the Odin satellite submillimeter measurement of the ground state transition of ortho-water at 557 GHz around the low-mass protostar IRAS16293-2422. The three following regions have been probed: the on-source position, and the two regions of interaction between the molecular outflows and the dense ambient cloud, i .e. on the SiO peak E1, and near the deuterated peak (cf Lis et al.(2002)). The three spectra reveal broad emission, with a narrow and deep absorption feature at the velocity of the quiescent gas. The water line profiles and intensities have been compared and combined with the CO(3- 2) and HCO+ lines from Lis et al.(2002) after convolution over the Odin beam. The contribution from the central envelope on the water line emission has been estimated with the infall model of Shoier et al. 2002. We show that the water emission is dominated by the outflows, particularly in the red wing of the lines. Using a c-shock modelling (Cabrit et al. 2005), we derive an abundance of X(H2O) 1 - 3 × 10-5 of H2, and shock velocities of 12 - 15 km/s. We also show that the absorption feature is due to the cold outer halo and corresponds to a lower limit of a few 10-9 on the H2O abundance.
Place, publisher, year, edition, pages
2005. Vol. 235, 227P- p.
ISM: abundances, ISM: individual: IRAS 16293, 2422, ISM: jets and outflows, ISM: molecules, stars: formation
Research subject Astronomy
IdentifiersURN: urn:nbn:se:su:diva-30912OAI: oai:DiVA.org:su-30912DiVA: diva2:274738