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Herschel Observations of Extraordinary Sources
- Source :
- The Astrophysical Journal, The Astrophysical Journal, American Astronomical Society, 2014, 787 (2), pp.112. ⟨10.1088/0004-637X/787/2/112⟩, The Astrophysical Journal, 787(2), 112-146. IOP PUBLISHING LTD
- Publication Year :
- 2014
-
Abstract
- We present a comprehensive analysis of a broad band spectral line survey of the Orion Kleinmann-Low nebula (Orion KL), one of the most chemically rich regions in the Galaxy, using the HIFI instrument on board the Herschel Space Observatory. This survey spans a frequency range from 480 to 1907 GHz at a resolution of 1.1 MHz. These observations thus encompass the largest spectral coverage ever obtained toward this high-mass star-forming region in the sub-mm with high spectral resolution, and include frequencies $>$ 1 THz where the Earth's atmosphere prevents observations from the ground. In all, we detect emission from 39 molecules (79 isotopologues). Combining this dataset with ground based mm spectroscopy obtained with the IRAM 30 m telescope, we model the molecular emission from the mm to the far-IR using the XCLASS program which assumes local thermodynamic equilibrium (LTE). Several molecules are also modeled with the MADEX non-LTE code. Because of the wide frequency coverage, our models are constrained by transitions over an unprecedented range in excitation energy. A reduced $��^{2}$ analysis indicates that models for most species reproduce the observed emission well. In particular, most complex organics are well fit by LTE implying gas densities are high ($>$10$^6$ cm$^{-3}$) and excitation temperatures and column densities are well constrained. Molecular abundances are computed using H$_{2}$ column densities also derived from the HIFI survey. The distribution of rotation temperatures, $T_{\rm rot}$, for molecules detected toward the hot core is significantly wider than the compact ridge, plateau, and extended ridge $T_{\rm rot}$ distributions, indicating the hot core has the most complex thermal structure.<br />Accepted to ApJ. 92 pages, 24 Figures, 9 Tables. Public data products may not be available yet
- Subjects :
- ISM: individual objects: Orion KL
FOS: Physical sciences
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Spectral line
ISM: abundances
law.invention
Telescope
law
Astrophysics::Solar and Stellar Astrophysics
Isotopologue
Spectral resolution
Spectroscopy
ComputingMilieux_MISCELLANEOUS
Astrophysics::Galaxy Astrophysics
Physics
[PHYS]Physics [physics]
Nebula
Astronomy and Astrophysics
Astrophysics - Astrophysics of Galaxies
Galaxy
ISM: molecules
13. Climate action
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Energy (signal processing)
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X and 15384357
- Database :
- OpenAIRE
- Journal :
- The Astrophysical Journal, The Astrophysical Journal, American Astronomical Society, 2014, 787 (2), pp.112. ⟨10.1088/0004-637X/787/2/112⟩, The Astrophysical Journal, 787(2), 112-146. IOP PUBLISHING LTD
- Accession number :
- edsair.doi.dedup.....e503bd13a33f76003df7f7ca9ca9ea76