Herschel/PACS Survey of protoplanetary disks in Taurus/ Auriga- Investigating the source of [OI] 63 μm line emission
Abstract
GASPS is a large Herschel Open time Key project studying the evolution of gas in protoplanetary disks. We target about 240 nearby objects in Taurus and young associations covering stellar ages between 0.3 - 30 Myr. We use the PACS instrument to observe continuum and selected gas tracers, like [{O}{I}] at 63 and 145 μm, [{C}{II}] at 158 μm as well as several molecular lines like OH, H_2O and CO. The strongest line we see is the [{O}{I}] at 63 μm. However, although it is clear that [{O}{I}] 63 μm traces gas in the disk, it is also strong in jets and outflows. Using the sources observed so far (42 sources detected in both line and continuum of 75 sources observed in spectroscopy and 92 in photometry) in Taurus/Auriga we explore how the [{O}{I}] 63 μm line strength correlates with 63 μm continuum, disk mass, accretion rate, stellar luminosity, and strength of the [{O}{I}] 6300 Å emission for both outflow and non-outflow sources. We find a clear, tight correlation between the strength of the [{O}{I}] 63 μm line emission and 63 μm continuum for non-outflow sources and a weaker correlation for outflow sources. In outflow sources the line can be up to 20 times stronger than in non-outflow sources, indicating that the [{O}{I}] 63 μm emission from the outflow will dominate over the disk emission. For the few sources where we also detect the [{O}{I}] 145 μm line, we find line ratios of 145 to 63 μm of 0.04 - 0.05, suggesting optically thin lines originating from gas with a temperature of a few 100 K, which suggests that the emission comes from the inner part/surface layers of the disk or from the shock regions in the outflow.
- Publication:
-
From Atoms to Pebbles: Herschel's view of Star and Planet Formation
- Pub Date:
- March 2012
- Bibcode:
- 2012faph.confE..33H