Linking high-J CO emission from low- to high-mass protostars with Herschel-HIFI

2011-05-31
San Jose-Garcia, Irene
Yıldız, Umut
Stars form in molecular clouds and the chemical composition of protostellar material depends strongly on the physical conditions at the different evolutionary stages. In order to better constrain the physical structure of young stellar objects (YSOs) across the entire mass spectrum (from < 1 to > 10^5 L_⊙), high--J (J ≤ 10) CO and isotopologue transitions are observed with the Heterodyne Instrument for the Far Infrared (HIFI) on Herschel. CO is a well--known tracer of physical conditions in YSOs and provides a reference to determine the abundances of other species. For this reason, CO observations are fundamental in the key program ``Water In Star--forming regions with Herschel'' (WISH), and highly complementary to those of water. The main goal of this work is to provide a link from low-- to high--mass YSOs by comparing the characteristics and properties of the CO emission line profiles. Similarities and differences in the spectra of different YSOs will be presented and various correlations investigated. Important results include the identification and characterization, by statistical analysis, of the multiple velocity components seen in the profiles of12CO (10-9) and13CO (10-9), structures also detected in water lines by HIFI. In addition, a strong correlation is found between the integrated intensity and the bolometric luminosity for all the CO and isotopologue emission lines, extending over three orders of magnitude. This correlation is also detected in each of the velocity components identified in the line profiles of12CO (10-9) and13CO (10-9). As a complement to the HIFI observations, spectra from ground--based telescopes are compared with the high--J CO data, widening the statistical analysis. Overall, the interaction of a protostar with its surroundings seems to have very similar characteristics across a wide range of luminosities. The Herschel data allow to quantify the different components.
The Molecular Universe, 280th Symposium of the International Astronomical Union
Citation Formats
I. San Jose-Garcia and U. Yıldız, “Linking high-J CO emission from low- to high-mass protostars with Herschel-HIFI,” presented at the The Molecular Universe, 280th Symposium of the International Astronomical Union, Toledo, İspanya, 2011, Accessed: 00, 2025. [Online]. Available: https://ui.adsabs.harvard.edu/abs/2011IAUS..280P.326S/abstract.