Physical conditions in the gas phases of the giant HII region LMC-N11: II. Origin of [CII] and fraction of CO-dark gas
hal.structure.identifier | Astrophysique Interprétation Modélisation [AIM (UMR7158 / UMR_E_9005 / UM_112)] | |
dc.contributor.author | LEBOUTEILLER, Vianney | |
hal.structure.identifier | Universität Heidelberg [Heidelberg] = Heidelberg University | |
dc.contributor.author | CORMIER, D. | |
hal.structure.identifier | Département d'Astrophysique (ex SAP) [DAP] | |
dc.contributor.author | MADDEN, S. C. | |
hal.structure.identifier | University of Cambridge [UK] [CAM] | |
dc.contributor.author | GALAMETZ, M. | |
hal.structure.identifier | Institut de Recherches sur les lois Fondamentales de l'Univers [IRFU] | |
dc.contributor.author | HONY, S. | |
hal.structure.identifier | Astrophysique Interprétation Modélisation [AIM (UMR7158 / UMR_E_9005 / UM_112)] | |
dc.contributor.author | GALLIANO, Frédéric | |
hal.structure.identifier | Astrophysique Interprétation Modélisation [AIM (UMR7158 / UMR_E_9005 / UM_112)] | |
dc.contributor.author | CHEVANCE, M. | |
dc.contributor.author | LEE, Min-Young | |
hal.structure.identifier | Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB] | |
dc.contributor.author | BRAINE, J. | |
hal.structure.identifier | Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA (UMR_8112)] | |
dc.contributor.author | POLLES, F. L. | |
dc.contributor.author | REQUEÑA-TORRES, M. Angel | |
dc.contributor.author | INDEBETOUW, R. | |
hal.structure.identifier | University of KwaZulu-Natal [Durban, Afrique du Sud] [UKZN] | |
dc.contributor.author | HUGHES, A. | |
hal.structure.identifier | University of Cincinnati [UC] | |
dc.contributor.author | ABEL, N. | |
dc.description.abstractEn | (abridged) The ambiguous origin of [CII] 158um in the interstellar medium complicates its use for diagnostics concerning the star-formation rate and physical conditions in photodissociation regions (PDRs). We observed the giant HII region N11 in the Large Magellanic Cloud with SOFIA/GREAT in order to investigate the origin of [CII] to obtain the total H2 gas content, the fraction of CO-dark H2 gas, and the influence of environmental effects such as stellar feedback. We present an innovative spectral decomposition method that allows statistical trends to be derived. The [CII] line is resolved in velocity and compared to HI and CO, using a Bayesian approach to decompose the profiles. A simple model accounting for collisions in the neutral atomic and molecular gas was used in order to derive the H2 column density traced by C+. The profile of [CII] most closely resembles that of CO, but the integrated [CII] line width lies between that of CO and that of HI. Using various methods, we find that [CII] mostly originates from the neutral gas. We show that [CII] mostly traces the CO-dark H2 gas but there is evidence of a weak contribution from neutral atomic gas preferentially in the faintest components. Most of the molecular gas is CO-dark. The fraction of CO-dark H2 gas decreases with increasing CO column density, with a slope that seems to depend on the impinging radiation field from nearby massive stars. Finally we extend previous measurements of the photoelectric-effect heating efficiency, which we find is constant across regions probed with Herschel, with [CII] and [OI] being the main coolants in faint and diffuse, and bright and compact regions, respectively, and with PAH emission tracing the CO-dark H2 gas heating where [CII] and [OI] emit. Our study highlights the importance of velocity-resolved PDR diagnostics and higher spatial resolution for HI observations. | |
dc.language.iso | en | |
dc.title.en | Physical conditions in the gas phases of the giant HII region LMC-N11: II. Origin of [CII] and fraction of CO-dark gas | |
dc.type | Document de travail - Pré-publication | |
dc.subject.hal | Physique [physics]/Astrophysique [astro-ph]/Cosmologie et astrophysique extra-galactique [astro-ph.CO] | |
dc.subject.hal | Physique [physics]/Astrophysique [astro-ph]/Astrophysique galactique [astro-ph.GA] | |
dc.subject.hal | Physique [physics]/Astrophysique [astro-ph]/Instrumentation et méthodes pour l'astrophysique [astro-ph.IM] | |
dc.subject.hal | Physique [physics]/Astrophysique [astro-ph]/Phénomènes cosmiques de haute energie [astro-ph.HE] | |
dc.identifier.arxiv | 1911.03280 | |
hal.identifier | hal-02380125 | |
hal.version | 1 | |
hal.origin.link | https://hal.archives-ouvertes.fr//hal-02380125v1 | |
bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.au=LEBOUTEILLER,%20Vianney&CORMIER,%20D.&MADDEN,%20S.%20C.&GALAMETZ,%20M.&HONY,%20S.&rft.genre=preprint |
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