Mostrar el registro sencillo del ítem

Spatially resolved images of reactive ions in the Orion Bar

dc.contributor.authorGOICOECHEA, Javier
dc.contributor.authorCUADRADO, S.
hal.structure.identifierInstitut de RadioAstronomie Millimétrique [IRAM]
hal.structure.identifierLaboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA]
dc.contributor.authorPETY, J.
hal.structure.identifierLaboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA]
dc.contributor.authorBRON, E.
hal.structure.identifierOnsala Space Observatory [OSO]
dc.contributor.authorBLACK, J. H.
hal.structure.identifierInstituto de Ciencia de Materiales de Madrid [ICMM]
dc.contributor.authorCERNICHARO, J.
hal.structure.identifierAMOR 2017
dc.contributor.authorCHAPILLON, E.
dc.contributor.authorFUENTE, A.
hal.structure.identifierLaboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA]
dc.contributor.authorGERIN, Maryvonne
dc.date.issued2017-04
dc.identifier.issn0004-6361
dc.description.abstractEnWe report high angular resolution (4.9" x 3.0") images of reactive ions SH+, HOC+, and SO+ toward the Orion Bar photodissociation region (PDR). We used ALMA-ACA to map several rotational lines at 0.8 mm, complemented with multi-line observations obtained with the IRAM 30m telescope. The SH+ and HOC+ emission is restricted to a narrow layer of 2"- to 10"-width (~800 to 4000 AU depending on the assumed PDR geometry) that follows the vibrationally excited H2^* emission. Both ions efficiently form very close to the H/H2 transition zone, at a depth of A_V < 1 mag into the neutral cloud, where abundant C+, S+, and H2^* coexist. SO+ peaks slightly deeper into the cloud. The observed ions have low rotational temperatures (T_rot~10-30 K << T_k) and narrow line-widths (~2-3 km/s), a factor of ~2 narrower that those of the lighter reactive ion CH+. This is consistent with the higher reactivity and faster radiative pumping rates of CH+ compared to the heavier ions, which are driven relatively faster toward smaller velocity dispersion by elastic collisions and toward lower T_rot by inelastic collisions. We estimate column densities and average physical conditions from a non-LTE excitation model (n(H2)~10^5-10^6 cm^-3, n(e^-)~10 cm^-3, and T_k~200 K). Regardless of the excitation details, SH+ and HOC+ clearly trace the most exposed layers of the UV-irradiated molecular cloud surface, whereas SO+ arises from slightly more shielded layers.
dc.language.isoen
dc.publisherEDP Sciences
dc.subject.enAstrophysics - Astrophysics of Galaxies
dc.title.enSpatially resolved images of reactive ions in the Orion Bar
dc.typeArticle de revue
dc.identifier.doi10.1051/0004-6361/201730716
dc.subject.halPlanète et Univers [physics]/Astrophysique [astro-ph]/Cosmologie et astrophysique extra-galactique [astro-ph.CO]
dc.identifier.arxiv1704.08621
bordeaux.journalAstronomy and Astrophysics - A&A
bordeaux.pageid.L9
bordeaux.volume601
bordeaux.peerReviewedoui
hal.identifierhal-01516644
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-01516644v1
bordeaux.COinSctx_ver=Z39.88-2004&amp;rft_val_fmt=info:ofi/fmt:kev:mtx:journal&amp;rft.jtitle=Astronomy%20and%20Astrophysics%20-%20A&A&amp;rft.date=2017-04&amp;rft.volume=601&amp;rft.spage=id.L9&amp;rft.epage=id.L9&amp;rft.eissn=0004-6361&amp;rft.issn=0004-6361&amp;rft.au=GOICOECHEA,%20Javier&amp;CUADRADO,%20S.&amp;PETY,%20J.&amp;BRON,%20E.&amp;BLACK,%20J.%20H.&amp;rft.genre=article


Archivos en el ítem

ArchivosTamañoFormatoVer

No hay archivos asociados a este ítem.

Este ítem aparece en la(s) siguiente(s) colección(ones)

Mostrar el registro sencillo del ítem