A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite - II. Data analysis

C. M. Persson; A. O. H. Olofsson; N. Koning; P. Bergman; P. Bernath; J. H. Black; U. Frisk; W. Geppert; T. I. Hasegawa; A. Hjalmarson; S. Kwok; B. Larsson; A. Lecacheux; A. Nummelin; M. Olberg; Aa. Sandqvist; E. S. Wirstrom

doi:10.1051/0004-6361:20077225

A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite - II. Data analysis

C. M. Persson, A. O. H. Olofsson, N. Koning, P. Bergman, P. Bernath, J. H. Black, U. Frisk, W. Geppert, T. I. Hasegawa, A. Hjalmarson, S. Kwok, B. Larsson, A. Lecacheux, A. Nummelin, M. Olberg, Aa. Sandqvist, E. S. Wirstrom

Chemistry

Research output: Contribution to journal › Literature review › peer-review

Abstract

Aims. We investigate thephysical and chemical conditions in a typical star forming region, including an unbiased search for new molecules in a spectral region previously unobserved.

Methods. Due to its proximity, the Orion KL region offers a unique laboratory of molecular astrophysics in a chemically rich, massive star forming region. Several ground- based spectral line surveys have been made, but due to the absorption by water and oxygen, the terrestrial atmosphere is completely opaque at frequencies around 487 and 557 GHz. To cover these frequencies we used the Odin satellite to perform a spectral line survey in the frequency ranges 486- 492 GHz and 541- 577 GHz, filling the gaps between previous spectral scans. Odin's high main beam effciency eta(mb) = 0.9, and observations performed outside the atmosphere make our intensity scale very well determined.

Results. We observed 280 spectral lines from 38 molecules including isotopologues, and, in addition, 64 unidentified lines. A few U- lines have interesting frequency coincidences such as ND and the anion SH-. The beam- averaged emission is dominated by CO, H2O, SO2, SO, (CO)-C-13 and CH3OH. Species with the largest number of lines are CH3OH, ( CH3) O-2, SO2, (CH3OH)-C-13, CH3CN and \NO. Six water lines are detected including the ground state rotational transition 11,(0) - 10,(1) of o- H2O, its isotopologues o- (H2O)-O-18 and o- H-2(17) 2 O, the Hot Core tracing p- H2O transition 62,4 - 71,7, and the 20,(2) - 11,(1) transition of HDO. Other lines of special interest are the 10 - 00 transition of NH3 and its isotopologue (NH3)-N-15. Isotopologue abundance ratios of D/ H, C-12/ C-13, S-32/ S-34, S-34/ S-33, and O-18/ O-17 are estimated. The temperatures, column densities and abundances in the various subregions are estimated, and we find very high gas- phase abundances of H2O, NH3, SO2, SO, NO, and CH3OH. A comparison with the ice inventory of ISO sheds new light on the origin of the abundant gas- phase molecules.

Original language	English
Pages (from-to)	807-U54
Number of pages	51
Journal	Astronomy & Astrophysics
Volume	476
Issue number	2
DOIs	https://doi.org/10.1051/0004-6361:20077225
Publication status	Published - Dec 2007

Keywords

ISM : abundances
ISM : individual objects : Orion KL
ISM : molecules
line : formation
line : identification submillimeter
MOLECULAR CLOUD CORES
STAR-FORMING REGIONS
MILLIMETER-WAVE OBSERVATIONS
GAS-GRAIN CHEMISTRY
INTERSTELLAR-MEDIUM
HOT CORE
SURFACE-CHEMISTRY
COLUMN DENSITIES
METHYL CYANIDE
1ST DETECTION

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10.1051/0004-6361:20077225

Cite this

Persson, C. M., Olofsson, A. O. H., Koning, N., Bergman, P., Bernath, P., Black, J. H., Frisk, U., Geppert, W., Hasegawa, T. I., Hjalmarson, A., Kwok, S., Larsson, B., Lecacheux, A., Nummelin, A., Olberg, M., Sandqvist, A., & Wirstrom, E. S. (2007). A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite - II. Data analysis. Astronomy & Astrophysics, 476(2), 807-U54. https://doi.org/10.1051/0004-6361:20077225

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title = "A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite - II. Data analysis",

abstract = "Aims. We investigate thephysical and chemical conditions in a typical star forming region, including an unbiased search for new molecules in a spectral region previously unobserved.Methods. Due to its proximity, the Orion KL region offers a unique laboratory of molecular astrophysics in a chemically rich, massive star forming region. Several ground- based spectral line surveys have been made, but due to the absorption by water and oxygen, the terrestrial atmosphere is completely opaque at frequencies around 487 and 557 GHz. To cover these frequencies we used the Odin satellite to perform a spectral line survey in the frequency ranges 486- 492 GHz and 541- 577 GHz, filling the gaps between previous spectral scans. Odin's high main beam effciency eta(mb) = 0.9, and observations performed outside the atmosphere make our intensity scale very well determined.Results. We observed 280 spectral lines from 38 molecules including isotopologues, and, in addition, 64 unidentified lines. A few U- lines have interesting frequency coincidences such as ND and the anion SH-. The beam- averaged emission is dominated by CO, H2O, SO2, SO, (CO)-C-13 and CH3OH. Species with the largest number of lines are CH3OH, ( CH3) O-2, SO2, (CH3OH)-C-13, CH3CN and \NO. Six water lines are detected including the ground state rotational transition 11,(0) - 10,(1) of o- H2O, its isotopologues o- (H2O)-O-18 and o- H-2(17) 2 O, the Hot Core tracing p- H2O transition 62,4 - 71,7, and the 20,(2) - 11,(1) transition of HDO. Other lines of special interest are the 10 - 00 transition of NH3 and its isotopologue (NH3)-N-15. Isotopologue abundance ratios of D/ H, C-12/ C-13, S-32/ S-34, S-34/ S-33, and O-18/ O-17 are estimated. The temperatures, column densities and abundances in the various subregions are estimated, and we find very high gas- phase abundances of H2O, NH3, SO2, SO, NO, and CH3OH. A comparison with the ice inventory of ISO sheds new light on the origin of the abundant gas- phase molecules.",

keywords = "ISM : abundances, ISM : individual objects : Orion KL, ISM : molecules, line : formation, line : identification submillimeter, MOLECULAR CLOUD CORES, STAR-FORMING REGIONS, MILLIMETER-WAVE OBSERVATIONS, GAS-GRAIN CHEMISTRY, INTERSTELLAR-MEDIUM, HOT CORE, SURFACE-CHEMISTRY, COLUMN DENSITIES, METHYL CYANIDE, 1ST DETECTION",

author = "Persson, {C. M.} and Olofsson, {A. O. H.} and N. Koning and P. Bergman and P. Bernath and Black, {J. H.} and U. Frisk and W. Geppert and Hasegawa, {T. I.} and A. Hjalmarson and S. Kwok and B. Larsson and A. Lecacheux and A. Nummelin and M. Olberg and Aa. Sandqvist and Wirstrom, {E. S.}",

year = "2007",

month = dec,

doi = "10.1051/0004-6361:20077225",

language = "English",

volume = "476",

pages = "807--U54",

journal = "Astronomy & Astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

number = "2",

}

Persson, CM, Olofsson, AOH, Koning, N, Bergman, P, Bernath, P, Black, JH, Frisk, U, Geppert, W, Hasegawa, TI, Hjalmarson, A, Kwok, S, Larsson, B, Lecacheux, A, Nummelin, A, Olberg, M, Sandqvist, A & Wirstrom, ES 2007, 'A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite - II. Data analysis', Astronomy & Astrophysics, vol. 476, no. 2, pp. 807-U54. https://doi.org/10.1051/0004-6361:20077225

TY - JOUR

T1 - A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite - II. Data analysis

AU - Persson, C. M.

AU - Olofsson, A. O. H.

AU - Koning, N.

AU - Bergman, P.

AU - Bernath, P.

AU - Black, J. H.

AU - Frisk, U.

AU - Geppert, W.

AU - Hasegawa, T. I.

AU - Hjalmarson, A.

AU - Kwok, S.

AU - Larsson, B.

AU - Lecacheux, A.

AU - Nummelin, A.

AU - Olberg, M.

AU - Sandqvist, Aa.

AU - Wirstrom, E. S.

PY - 2007/12

Y1 - 2007/12

N2 - Aims. We investigate thephysical and chemical conditions in a typical star forming region, including an unbiased search for new molecules in a spectral region previously unobserved.Methods. Due to its proximity, the Orion KL region offers a unique laboratory of molecular astrophysics in a chemically rich, massive star forming region. Several ground- based spectral line surveys have been made, but due to the absorption by water and oxygen, the terrestrial atmosphere is completely opaque at frequencies around 487 and 557 GHz. To cover these frequencies we used the Odin satellite to perform a spectral line survey in the frequency ranges 486- 492 GHz and 541- 577 GHz, filling the gaps between previous spectral scans. Odin's high main beam effciency eta(mb) = 0.9, and observations performed outside the atmosphere make our intensity scale very well determined.Results. We observed 280 spectral lines from 38 molecules including isotopologues, and, in addition, 64 unidentified lines. A few U- lines have interesting frequency coincidences such as ND and the anion SH-. The beam- averaged emission is dominated by CO, H2O, SO2, SO, (CO)-C-13 and CH3OH. Species with the largest number of lines are CH3OH, ( CH3) O-2, SO2, (CH3OH)-C-13, CH3CN and \NO. Six water lines are detected including the ground state rotational transition 11,(0) - 10,(1) of o- H2O, its isotopologues o- (H2O)-O-18 and o- H-2(17) 2 O, the Hot Core tracing p- H2O transition 62,4 - 71,7, and the 20,(2) - 11,(1) transition of HDO. Other lines of special interest are the 10 - 00 transition of NH3 and its isotopologue (NH3)-N-15. Isotopologue abundance ratios of D/ H, C-12/ C-13, S-32/ S-34, S-34/ S-33, and O-18/ O-17 are estimated. The temperatures, column densities and abundances in the various subregions are estimated, and we find very high gas- phase abundances of H2O, NH3, SO2, SO, NO, and CH3OH. A comparison with the ice inventory of ISO sheds new light on the origin of the abundant gas- phase molecules.

AB - Aims. We investigate thephysical and chemical conditions in a typical star forming region, including an unbiased search for new molecules in a spectral region previously unobserved.Methods. Due to its proximity, the Orion KL region offers a unique laboratory of molecular astrophysics in a chemically rich, massive star forming region. Several ground- based spectral line surveys have been made, but due to the absorption by water and oxygen, the terrestrial atmosphere is completely opaque at frequencies around 487 and 557 GHz. To cover these frequencies we used the Odin satellite to perform a spectral line survey in the frequency ranges 486- 492 GHz and 541- 577 GHz, filling the gaps between previous spectral scans. Odin's high main beam effciency eta(mb) = 0.9, and observations performed outside the atmosphere make our intensity scale very well determined.Results. We observed 280 spectral lines from 38 molecules including isotopologues, and, in addition, 64 unidentified lines. A few U- lines have interesting frequency coincidences such as ND and the anion SH-. The beam- averaged emission is dominated by CO, H2O, SO2, SO, (CO)-C-13 and CH3OH. Species with the largest number of lines are CH3OH, ( CH3) O-2, SO2, (CH3OH)-C-13, CH3CN and \NO. Six water lines are detected including the ground state rotational transition 11,(0) - 10,(1) of o- H2O, its isotopologues o- (H2O)-O-18 and o- H-2(17) 2 O, the Hot Core tracing p- H2O transition 62,4 - 71,7, and the 20,(2) - 11,(1) transition of HDO. Other lines of special interest are the 10 - 00 transition of NH3 and its isotopologue (NH3)-N-15. Isotopologue abundance ratios of D/ H, C-12/ C-13, S-32/ S-34, S-34/ S-33, and O-18/ O-17 are estimated. The temperatures, column densities and abundances in the various subregions are estimated, and we find very high gas- phase abundances of H2O, NH3, SO2, SO, NO, and CH3OH. A comparison with the ice inventory of ISO sheds new light on the origin of the abundant gas- phase molecules.

KW - ISM : abundances

KW - ISM : individual objects : Orion KL

KW - ISM : molecules

KW - line : formation

KW - line : identification submillimeter

KW - MOLECULAR CLOUD CORES

KW - STAR-FORMING REGIONS

KW - MILLIMETER-WAVE OBSERVATIONS

KW - GAS-GRAIN CHEMISTRY

KW - INTERSTELLAR-MEDIUM

KW - HOT CORE

KW - SURFACE-CHEMISTRY

KW - COLUMN DENSITIES

KW - METHYL CYANIDE

KW - 1ST DETECTION

U2 - 10.1051/0004-6361:20077225

DO - 10.1051/0004-6361:20077225

M3 - Literature review

VL - 476

SP - 807-U54

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

IS - 2

ER -