Astronomy and Astrophysics – Astronomy
Scientific paper
May 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011iaus..280p.308p&link_type=abstract
The Molecular Universe, Posters from the proceedings of the 280th Symposium of the International Astronomical Union held in Tole
Astronomy and Astrophysics
Astronomy
Scientific paper
Stellar outflows are observed in association with young accreting stars and are believed to play a key role in the star formation process. They may be responsible for the removal of excess angular momentum from the disk and the dispersal of the parental envelope. The strong shocks produced by the propagation of outflowing gas in the interstellar medium produce large temperature and density gradients. Thus, a comprehensive view of the outflow process requires a multi-wavelength analysis ensuring a complete census of the different components contributing to the cooling. The cold wide-angle outflow (T˜ 10-20 K) can be probed through millimeter molecular lines (e.g., low-J CO, SiO), while the collimated highly-excited jet is traced by optical and UV atomic lines (T˜ 10^4 K). Herschel opens a new window on the far-infrared range allowing us to probe the "warm" gas component excited at intermediate temperature (~100-2000 K). The GASPS (GAS in Protoplanetary Systems) Herschel Open Time Key Project, devoted to study gas evolution in protoplanetary disks, includes also a number of jet sources, observed in atomic (OI, CII) and molecular (CO, H2O, OH) lines with PACS. Previous ISO observations focused on outflows from very young sources (Class 0/I). Thanks to Herschel higher sensitivity (down to ˜ 10-18 W/m^2), the GASPS survey allow us for the first time to study the far-infrared counterpart of brigth optical jets from evolved Class II sources. The FIR spectra show extended and velocity shifted emission in atomic lines, such as [OI]63, 145um, and [CII]158um lines, as well as in molecular high-J CO, OH, and H2O lines. We compare the distribution and velocity of the detected FIR lines with ground-based observations taken at optical and millimeter wavelengths. This allow us to obtain a comprehensive picture of energy dissipation in the shocks occurring along the jet and to compute the total mass loss rate, a fundamental parameter to investigate the tight relationship between accretion and ejection processes. Finally we compare line ratios and fluxes measured for sources with and without outflow-signatures with shock/disk model predictions. The line ratios analysis, coupled with follow-up high spectral resolution HIFI observations, is intended to provide a useful tool to discriminate between jet and disk emission in the unresolved circumstellar region.
Herschel GASPS Team
Podio Linda
No associations
LandOfFree
Herschel/PACS observations of young sources in Taurus: the far-infrared counterpart of optical jets does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Herschel/PACS observations of young sources in Taurus: the far-infrared counterpart of optical jets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Herschel/PACS observations of young sources in Taurus: the far-infrared counterpart of optical jets will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-930615