A molecular line survey of Sagittarius B2 and Orion-KL from 70 to 115 GHz. II - Analysis of the data

Journal Article · Sat Jun 01 04:00:00 EDT 1991 · Astrophysical Journal, Supplement Series; (United States)

DOI:https://doi.org/10.1086/191577· OSTI ID:5587411

Turner, B E ^[1]

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1. National Radio Astronomy Observatory, Charlottesville, VA (USA)

Over 800 lines in OMC-1 and over 700 in Sgr B2 were observed in the NRAO 3-mm survey. Detailed LTE analysis of 33 species has been performed using numbers of transitions in the range 4-98. Limitations of the LTE optically thin approach are emphasized, in particular its failure to account for the anomalously strong emission from intrisically weak transitions in all the most complex species including CH3OHCO, (CH3)2O, CH3CHO, EtOH, NH2CHO, CH2CHCN, and EtCN. A detailed radiative-transfer analysis of all species with a sufficient number of transitions was also performed. The intensity and abundance ratios of the existing 3-mm surveys of Sgr B2 (NRAO, BTL) and OMC-1 (NRAO, Onsala) are compared to deduce the relative contributions to the emission of each molecular species from compact hot sources and from extended cool regions. It is concluded that the chemistries of the two regions are similar, which suggests a similar cosmic-ray flux, evolutionary stage, and elemental abundance distribution. 90 refs.

• OSTI ID: 5587411
• Journal Information: Astrophysical Journal, Supplement Series; (United States), Journal Name: Astrophysical Journal, Supplement Series; (United States) Vol. 76; ISSN APJSA; ISSN 0067-0049
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CARBON ISOTOPES
CHEMICAL COMPOSITION
CHEMISTRY
COMPARATIVE EVALUATIONS
COSMIC GASES
COSMOCHEMISTRY
DATA ANALYSIS
ELEMENT ABUNDANCE
EQUILIBRIUM
FLUIDS
GALACTIC EVOLUTION
GASES
HYDROCARBONS
INTERSTELLAR SPACE
ISOTOPES
LTE
MOLECULES
ORGANIC COMPOUNDS
RADIATION TRANSPORT
SPACE