Odin observations of the Galactic centre in the 118-GHz band: Upper limit to the O2 abundance

Aa Sandqvist; B. Larsson; Å Hjalmarson; P. Bergman; P. Bernath; U. Frisk; M. Olberg; L. Pagani; L. M. Ziurys

doi:10.1051/0004-6361:200809436

Odin observations of the Galactic centre in the 118-GHz band: Upper limit to the O₂ abundance

Aa Sandqvist, B. Larsson, Å Hjalmarson, P. Bergman, P. Bernath, U. Frisk, M. Olberg, L. Pagani, L. M. Ziurys

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

14 Scopus citations

Abstract

Aims. The Odin satellite has been used to search for the 118.75-GHz line of molecular oxygen (O) in the Galactic centre.Methods. Odin observations were performed towards the Sgr circumnuclear disk (CND), and the Sgr A +20 km s and +50 km s molecular clouds using the position-switching mode. Supplementary ground-based observations were carried out in the 2-mm band using the ARO Kitt Peak 12-m telescope to examine suspected SiC features.Results. A strong emission line was found at 118.27 GHz, attributable to the HCN line. Upper limits are presented for the 118.75-GHz O ground transition line and for the 118.11-GHz , ground state SiC line at the Galactic centre. Upper limits are also presented for the 487-GHz O line in the Sgr A +50 km s cloud and for the 157-GHz, , SiC line in the Sgr A +20 and +50 km s clouds, as well as the CND. The CHOH line complex at 157.2-157.3 GHz has been detected in the +20 and +50 kms clouds but not towards Sgr /CND.Conclusions. A upper limit for the fractional abundance ratio of [ O] /[ H] is found to be (O) towards the Sgr A molecular belt region.

Original language	English (US)
Pages (from-to)	849-853
Number of pages	5
Journal	Astronomy and astrophysics
Volume	482
Issue number	3
DOIs	https://doi.org/10.1051/0004-6361:200809436
State	Published - May 2008

Keywords

Galaxy: center
ISM: abundances
ISM: clouds
ISM: individual objects: Sgr A
ISM: molecules

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1051/0004-6361:200809436

Cite this

@article{6dad2a9169614184b61d89cece5b08e1,

title = "Odin observations of the Galactic centre in the 118-GHz band: Upper limit to the O2 abundance",

abstract = "Aims. The Odin satellite has been used to search for the 118.75-GHz line of molecular oxygen (O) in the Galactic centre.Methods. Odin observations were performed towards the Sgr circumnuclear disk (CND), and the Sgr A +20 km s and +50 km s molecular clouds using the position-switching mode. Supplementary ground-based observations were carried out in the 2-mm band using the ARO Kitt Peak 12-m telescope to examine suspected SiC features.Results. A strong emission line was found at 118.27 GHz, attributable to the HCN line. Upper limits are presented for the 118.75-GHz O ground transition line and for the 118.11-GHz , ground state SiC line at the Galactic centre. Upper limits are also presented for the 487-GHz O line in the Sgr A +50 km s cloud and for the 157-GHz, , SiC line in the Sgr A +20 and +50 km s clouds, as well as the CND. The CHOH line complex at 157.2-157.3 GHz has been detected in the +20 and +50 kms clouds but not towards Sgr /CND.Conclusions. A upper limit for the fractional abundance ratio of [ O] /[ H] is found to be (O) towards the Sgr A molecular belt region.",

keywords = "Galaxy: center, ISM: abundances, ISM: clouds, ISM: individual objects: Sgr A, ISM: molecules",

author = "Aa Sandqvist and B. Larsson and {\AA} Hjalmarson and P. Bergman and P. Bernath and U. Frisk and M. Olberg and L. Pagani and Ziurys, {L. M.}",

year = "2008",

month = may,

doi = "10.1051/0004-6361:200809436",

language = "English (US)",

volume = "482",

pages = "849--853",

journal = "Astronomy and astrophysics",

issn = "0004-6361",

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number = "3",

}

TY - JOUR

T1 - Odin observations of the Galactic centre in the 118-GHz band

T2 - Upper limit to the O2 abundance

AU - Sandqvist, Aa

AU - Larsson, B.

AU - Hjalmarson, Å

AU - Bergman, P.

AU - Bernath, P.

AU - Frisk, U.

AU - Olberg, M.

AU - Pagani, L.

AU - Ziurys, L. M.

PY - 2008/5

Y1 - 2008/5

N2 - Aims. The Odin satellite has been used to search for the 118.75-GHz line of molecular oxygen (O) in the Galactic centre.Methods. Odin observations were performed towards the Sgr circumnuclear disk (CND), and the Sgr A +20 km s and +50 km s molecular clouds using the position-switching mode. Supplementary ground-based observations were carried out in the 2-mm band using the ARO Kitt Peak 12-m telescope to examine suspected SiC features.Results. A strong emission line was found at 118.27 GHz, attributable to the HCN line. Upper limits are presented for the 118.75-GHz O ground transition line and for the 118.11-GHz , ground state SiC line at the Galactic centre. Upper limits are also presented for the 487-GHz O line in the Sgr A +50 km s cloud and for the 157-GHz, , SiC line in the Sgr A +20 and +50 km s clouds, as well as the CND. The CHOH line complex at 157.2-157.3 GHz has been detected in the +20 and +50 kms clouds but not towards Sgr /CND.Conclusions. A upper limit for the fractional abundance ratio of [ O] /[ H] is found to be (O) towards the Sgr A molecular belt region.

AB - Aims. The Odin satellite has been used to search for the 118.75-GHz line of molecular oxygen (O) in the Galactic centre.Methods. Odin observations were performed towards the Sgr circumnuclear disk (CND), and the Sgr A +20 km s and +50 km s molecular clouds using the position-switching mode. Supplementary ground-based observations were carried out in the 2-mm band using the ARO Kitt Peak 12-m telescope to examine suspected SiC features.Results. A strong emission line was found at 118.27 GHz, attributable to the HCN line. Upper limits are presented for the 118.75-GHz O ground transition line and for the 118.11-GHz , ground state SiC line at the Galactic centre. Upper limits are also presented for the 487-GHz O line in the Sgr A +50 km s cloud and for the 157-GHz, , SiC line in the Sgr A +20 and +50 km s clouds, as well as the CND. The CHOH line complex at 157.2-157.3 GHz has been detected in the +20 and +50 kms clouds but not towards Sgr /CND.Conclusions. A upper limit for the fractional abundance ratio of [ O] /[ H] is found to be (O) towards the Sgr A molecular belt region.

KW - Galaxy: center

KW - ISM: abundances

KW - ISM: clouds

KW - ISM: individual objects: Sgr A

KW - ISM: molecules

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