First results of the Herschel key program "Dust, Ice and Gas In Time" (DIGIT): Dust and gas spectroscopy of HD 100546
- Autor(en)
- Bernhard Sturm, Jeroen Bouwman, Thomas Henning, Neal Evans, Bram Acke, Gijs Mulders, Rens L.B.F.M. Waters, Ewine Fleur van Dishoeck, Gwendolyn Meeus, James Green, Jean-Charles Augereau, Johan Olofsson, Colette Salyk, Joan Najita, Gregory Herczeg, Tim A. van Kempen, Lars E. Kristensen, Carsten Dominik, John Carr, Christoffel Waelkens, Edwin Ted Bergin, Geoffrey A. Blake, Joanna Brown, Jianli Chen, Lucas Cieza, Mike Dunham, Al Glassgold, Manuel Güdel, Paul M. Harvey, Michiel R. Hogerheijde, Daniel Jaffe, Jes K. Jorgensen, Hyo-Young Kim, Claudia Knez, John H. Lacy, Jeong-Eun Lee, Sebastian Maret, Rowin Meijerink, Bruno Merin, Lee Mundy, Klaus M. Pontoppidan, Ruud Visser, Umut A. Yildiz
- Abstrakt
Context. We present far-infrared spectroscopic observations, taken with the Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory, of the protoplanetary disk around the pre-main-sequence star HD?100546. These observations are the first within the DIGIT Herschel key program, which aims to follow the evolution of dust, ice, and gas from young stellar objects still embedded in their parental molecular cloud core, through the final pre-main-sequence phases when the circumstellar disks are dissipated.
Aims. Our aim is to improve the constraints on temperature and chemical composition of the crystalline olivines in the disk of HD?100546 and to give an inventory of the gas lines present in its far-infrared spectrum.
Methods. The 69?µm feature is analyzed in terms of position and shape to derive the dust temperature and composition. Furthermore, we detected 32 emission lines from five gaseous species and measured their line fluxes.
Results. The 69?µm emission comes either from dust grains with ~70 K at radii larger than 50?AU, as suggested by blackbody fitting, or it arises from ~200?K dust at ~13?AU, close to the midplane, as supported by radiative transfer models. We also conclude that the forsterite crystals have few defects and contain at most a few percent iron by mass. Forbidden line emission from [C ii] at 157?µm and [O i] at 63 and 145?µm, most likely due to photodissociation by stellar photons, is detected. Furthermore, five H2O and several OH lines are detected. We also found high-J rotational transition lines of CO, with rotational temperatures of ~300?K for the transitions up to J = 22–21 and T ~ 800?K for higher transitions.
- Organisation(en)
- Institut für Astrophysik
- Externe Organisation(en)
- Max-Planck-Institut für Astronomie, University of Texas, Austin, Katholieke Universiteit Leuven, University of Amsterdam (UvA), Leiden University, Universidad Autónoma de Madrid, Observatoire des sciences de l'univers de Grenoble, National Optical Astronomy Observatory, Tucson, Max-Planck-Institut für extraterrestrische Physik, Harvard-Smithsonian Center for Astrophysics, U.S. Naval Research Laboratory, University of Michigan, California Institute of Technology (Caltech), University of Hawaii, University of California, Berkeley, University of Copenhagen, University of Maryland, College Park, Sejong University, European Space Astronomy Centre (ESA)
- Journal
- Astronomy & Astrophysics
- Band
- 518
- Anzahl der Seiten
- 5
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/201014674
- Publikationsdatum
- 2010
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103003 Astronomie
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/910de255-5216-4ad0-940e-49f3f6cf6c88