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Sökning: onr:"swepub:oai:research.chalmers.se:80592fb7-f295-4186-a4b5-b5d6231a5c19" > Quantitative infere...

LIBRIS Formathandbok  (Information om MARC21)
FältnamnIndikatorerMetadata
00006158naa a2200673 4500
001oai:research.chalmers.se:80592fb7-f295-4186-a4b5-b5d6231a5c19
003SwePub
008210121s2021 | |||||||||||000 ||eng|
0247 a https://research.chalmers.se/publication/5220162 URI
0247 a https://doi.org/10.1051/0004-6361/2020378712 DOI
040 a (SwePub)cth
041 a engb eng
042 9 SwePub
072 7a art2 swepub-publicationtype
072 7a ref2 swepub-contenttype
1001 a Gratier, Pierreu Université de Bordeaux,University of Bordeaux4 aut
2451 0a Quantitative inference of the H2 column densities from 3mm molecular emission: case study towards Orion B
264 c 2020-12-23
264 1b EDP Sciences,c 2021
338 a electronic2 rdacarrier
520 a Context. Based on the finding that molecular hydrogen is unobservable in cold molecular clouds, the column density measurements of molecular gas currently rely either on dust emission observation in the far-infrared, which requires space telescopes, or on star counting, which is limited in angular resolution by the stellar density. The (sub)millimeter observations of numerous trace molecules can be effective using ground-based telescopes, but the relationship between the emission of one molecular line and the H-2 column density is non-linear and sensitive to excitation conditions, optical depths, and abundance variations due to the underlying physico- chemistry.Aims. We aim to use multi-molecule line emission to infer the H-2 molecular column density from radio observations.Methods. We propose a data-driven approach to determine the H-2 gas column densities from radio molecular line observations. We use supervised machine-learning methods (random forest) on wide-field hyperspectral IRAM-30m observations of the Orion B molecular cloud to train a predictor of the H-2 column density, using a limited set of molecular lines between 72 and 116 GHz as input, and the Herschel-based dust-derived column densities as "ground truth" output.Results. For conditions similar to those of the Orion B molecular cloud, we obtained predictions of the H-2 column density within a typical factor of 1.2 from the Herschel-based column density estimates. A global analysis of the contributions of the different lines to the predictions show that the most important lines are (CO)-C-13(1-0), (CO)-C-12(1-0), (CO)-O-18(1-0), and HCO+(1-0). A detailed analysis distinguishing between diffuse, translucent, filamentary, and dense core conditions show that the importance of these four lines depends on the regime, and that it is recommended that the N2H+(1-0) and CH3OH(2(0)-1(0)) lines be added for the prediction of the H-2 column density in dense core conditions.Conclusions. This article opens a promising avenue for advancing direct inferencing of important physical parameters from the molecular line emission in the millimeter domain. The next step will be to attempt to infer several parameters simultaneously (e.g., the column density and far-UV illumination field) to further test the method.
650 7a NATURVETENSKAPx Fysikx Astronomi, astrofysik och kosmologi0 (SwePub)103052 hsv//swe
650 7a NATURAL SCIENCESx Physical Sciencesx Astronomy, Astrophysics and Cosmology0 (SwePub)103052 hsv//eng
650 7a NATURVETENSKAPx Fysikx Atom- och molekylfysik och optik0 (SwePub)103022 hsv//swe
650 7a NATURAL SCIENCESx Physical Sciencesx Atom and Molecular Physics and Optics0 (SwePub)103022 hsv//eng
650 7a NATURVETENSKAPx Kemix Teoretisk kemi0 (SwePub)104072 hsv//swe
650 7a NATURAL SCIENCESx Chemical Sciencesx Theoretical Chemistry0 (SwePub)104072 hsv//eng
653 a methods: statistical
653 a ISM: clouds
653 a ISM: molecules
7001 a Pety, Jeromeu Institut de Radioastronomie Millimétrique (IRAM),PSL University Paris4 aut
7001 a Bron, Emericu PSL University Paris4 aut
7001 a Roueff, Antoineu Aix-Marseille Université,Aix Marseille University4 aut
7001 a Orkisz, Jan,d 1991u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)orkisz
7001 a Gerin, Maryvonneu PSL University Paris4 aut
7001 a Magalhaes, Victor de Souzau Institut de Radioastronomie Millimétrique (IRAM)4 aut
7001 a Gaudel, Mathildeu PSL University Paris4 aut
7001 a Vono, Maximeu Université de Toulouse,University of Toulouse4 aut
7001 a Bardeau, Sebastienu Institut de Radioastronomie Millimétrique (IRAM)4 aut
7001 a Chanussot, Jocelynu Université Grenoble Alpes,Grenoble Alpes University4 aut
7001 a Chainais, Pierreu Université de Lille,University of Lille4 aut
7001 a Goicoechea, Javier R.u CSIC - Instituto de Fisica Fundamental (IFF)4 aut
7001 a Guzman, Viviana V.u Pontificia Universidad Catolica de Chile4 aut
7001 a Hughes, Annieu Universite Paul Sabatier Toulouse III,Paul Sabatier University4 aut
7001 a Kainulainen, Jouni,d 1979u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)jounik
7001 a Languignon, Davidu PSL University Paris4 aut
7001 a Le Bourlot, Jacquesu PSL University Paris4 aut
7001 a Le Petit, Francku PSL University Paris4 aut
7001 a Levrier, Francoisu PSL University Paris4 aut
7001 a Liszt, Harveyu National Radio Astronomy Observatory4 aut
7001 a Peretto, Nicolasu Cardiff University4 aut
7001 a Rouefe, Evelyneu PSL University Paris4 aut
7001 a Sievers, Albrechtu Institut de Radioastronomie Millimétrique (IRAM)4 aut
7102 a Université de Bordeauxb Institut de Radioastronomie Millimétrique (IRAM)4 org
7730 t Astronomy and Astrophysicsd : EDP Sciencesg 645q 645x 0004-6361x 1432-0746
8564 u https://research.chalmers.se/publication/522016/file/522016_Fulltext.pdfx primaryx freey FULLTEXT
8564 u https://www.aanda.org/articles/aa/pdf/2021/01/aa37871-20.pdf
8564 8u https://research.chalmers.se/publication/522016
8564 8u https://doi.org/10.1051/0004-6361/202037871

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