Dust, Ice, and Gas In Time (DIGIT) Herschel program first results: A full PACS-SED scan of the gas line emission in protostar DK Chamaeleontis
- Author(s)
- Tim A. van Kempen, James Green, Neal Evans, Ewine Fleur van Dishoeck, Lars E. Kristensen, Manuel Güdel
- Abstract
Aims. We aim to study the composition and energetics of the circumstellar material of DK Cha, an intermediate-mass star in transition from an embedded configuration to a star plus disk stage, during this pivotal stage of its evolution.
Methods. Using the range scan mode of PACS on the Herschel Space Observatory, we obtained a spectrum of DK Cha from 55 to 210 µm as part of the DIGIT key program.
Results. Almost 50 molecular and atomic lines were detected, many more than the 7 lines detected in ISO-LWS. Nearly the entire ladder of CO from J = 14–13 to 38–37 (Eu/k = 4080 K), water from levels as excited as = 707 (Eu/k = 843 K), and OH lines up to Eu/k = 290 K were detected.
Conclusions. The continuum emission in our PACS SED scan matches the flux expected by a model consisting of a star, a surrounding disk of 0.03 , and an envelope of a similar mass, supporting the suggestion that the object is emerging from its main accretion stage. Molecular, atomic, and ionic emission lines in the far-infrared reveal the outflow's influence on the envelope. The inferred hot gas may be photon-heated, but some emission may be caused by C-shocks in the walls of the outflow cavity.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Harvard-Smithsonian Center for Astrophysics, University of Texas, Austin, Leiden University
- Journal
- Astronomy & Astrophysics
- Volume
- 518
- No. of pages
- 5
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/201014686
- Publication date
- 2010
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/816cba4c-663f-4e15-a752-1c7a7d47830e