Extended Carbon Emission in the Galaxy: Dark Gas along the G328 Sightline
Abstract We present spectral data cubes of the [CI] 809 GHz, 12 CO 115 GHz, 13 CO 110 GHz and HI 1.4 GHz line emission from a ~1° region along the l = 328° (G328) sightline in the Galactic Plane. The [CI] data comes from the High Elevation Antarctic Terahertz telescope at Ridge A on the summit of th...
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crcambridgeupr:10.1017/s1743921316007717 2023-05-15T14:09:20+02:00 Extended Carbon Emission in the Galaxy: Dark Gas along the G328 Sightline Burton, M. Ashley, M. Braiding, C. Freeman, M. Kulesa, C. Wolfire, M. Hollenbach, D. Rowell, G. Lau, J. 2015 http://dx.doi.org/10.1017/s1743921316007717 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1743921316007717 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Proceedings of the International Astronomical Union volume 11, issue S315 ISSN 1743-9213 1743-9221 Astronomy and Astrophysics Space and Planetary Science journal-article 2015 crcambridgeupr https://doi.org/10.1017/s1743921316007717 2022-04-07T09:00:38Z Abstract We present spectral data cubes of the [CI] 809 GHz, 12 CO 115 GHz, 13 CO 110 GHz and HI 1.4 GHz line emission from a ~1° region along the l = 328° (G328) sightline in the Galactic Plane. The [CI] data comes from the High Elevation Antarctic Terahertz telescope at Ridge A on the summit of the Antarctic plateau, where the extremely low levels of precipitable water vapour open atmospheric windows for THz observations. The CO data comes from the Southern Galactic Plane Survey being conducted with the Mopra telescope. Emission arises principally from gas in three spiral arm crossings along the sight line. The distribution of the emission in the CO and [CI] lines is found to be similar, with the [CI] slightly more extended, and both are enveloped in extensive HI. Spectral line ratios are similar across the entire extent of the Galaxy. However, towards the edges of the molecular clouds the [CI]/ 13 CO and 12 CO/ 13 CO line ratios rise by ~ 50%, and the [CI]/H i ratio falls by ~ 10%. We attribute this to sightlines passing predominantly through the surfaces of photodissociation regions (PDRs), where the carbon is found mainly as C or C + rather than CO, while the gas is mostly molecular. This is the signature of dark molecular gas. Article in Journal/Newspaper Antarc* Antarctic Cambridge University Press (via Crossref) Antarctic The Antarctic Proceedings of the International Astronomical Union 11 S315 |
institution |
Open Polar |
collection |
Cambridge University Press (via Crossref) |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Astronomy and Astrophysics Space and Planetary Science |
spellingShingle |
Astronomy and Astrophysics Space and Planetary Science Burton, M. Ashley, M. Braiding, C. Freeman, M. Kulesa, C. Wolfire, M. Hollenbach, D. Rowell, G. Lau, J. Extended Carbon Emission in the Galaxy: Dark Gas along the G328 Sightline |
topic_facet |
Astronomy and Astrophysics Space and Planetary Science |
description |
Abstract We present spectral data cubes of the [CI] 809 GHz, 12 CO 115 GHz, 13 CO 110 GHz and HI 1.4 GHz line emission from a ~1° region along the l = 328° (G328) sightline in the Galactic Plane. The [CI] data comes from the High Elevation Antarctic Terahertz telescope at Ridge A on the summit of the Antarctic plateau, where the extremely low levels of precipitable water vapour open atmospheric windows for THz observations. The CO data comes from the Southern Galactic Plane Survey being conducted with the Mopra telescope. Emission arises principally from gas in three spiral arm crossings along the sight line. The distribution of the emission in the CO and [CI] lines is found to be similar, with the [CI] slightly more extended, and both are enveloped in extensive HI. Spectral line ratios are similar across the entire extent of the Galaxy. However, towards the edges of the molecular clouds the [CI]/ 13 CO and 12 CO/ 13 CO line ratios rise by ~ 50%, and the [CI]/H i ratio falls by ~ 10%. We attribute this to sightlines passing predominantly through the surfaces of photodissociation regions (PDRs), where the carbon is found mainly as C or C + rather than CO, while the gas is mostly molecular. This is the signature of dark molecular gas. |
format |
Article in Journal/Newspaper |
author |
Burton, M. Ashley, M. Braiding, C. Freeman, M. Kulesa, C. Wolfire, M. Hollenbach, D. Rowell, G. Lau, J. |
author_facet |
Burton, M. Ashley, M. Braiding, C. Freeman, M. Kulesa, C. Wolfire, M. Hollenbach, D. Rowell, G. Lau, J. |
author_sort |
Burton, M. |
title |
Extended Carbon Emission in the Galaxy: Dark Gas along the G328 Sightline |
title_short |
Extended Carbon Emission in the Galaxy: Dark Gas along the G328 Sightline |
title_full |
Extended Carbon Emission in the Galaxy: Dark Gas along the G328 Sightline |
title_fullStr |
Extended Carbon Emission in the Galaxy: Dark Gas along the G328 Sightline |
title_full_unstemmed |
Extended Carbon Emission in the Galaxy: Dark Gas along the G328 Sightline |
title_sort |
extended carbon emission in the galaxy: dark gas along the g328 sightline |
publisher |
Cambridge University Press (CUP) |
publishDate |
2015 |
url |
http://dx.doi.org/10.1017/s1743921316007717 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1743921316007717 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Proceedings of the International Astronomical Union volume 11, issue S315 ISSN 1743-9213 1743-9221 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s1743921316007717 |
container_title |
Proceedings of the International Astronomical Union |
container_volume |
11 |
container_issue |
S315 |
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1766281344100335616 |