Mid-infrared observations of methanol maser sites and ultracompact H II regions: Signposts of high-mass star formation Walsh, Andrew en_US Bertoldi, F en_US Burton, Michael en_US Nikola, Thomas en_US 2021-11-25T13:02:43Z 2021-11-25T13:02:43Z 2001 en_US
dc.description.abstract N-band (10.5 μm) and/or Q-band (20.0 μm) images taken with MANIAC on the ESO/MPI 2.2-m telescope are presented for 31 methanol maser sites and 19 ultracompact (UC) H ii regions. Most of the maser sites and UC H ii regions are coincident with mid-infrared (MIR) sources to within the positional uncertainties of ∼ 3 arcsec, consistent with the maser emission being powered by the MIR source. The IRAS source positions, however, do not always coincide with the MIR sources. Based on an average infrared spectral energy distribution, we deduce that the MIR objects are luminous enough that they should also produce a strong ionizing radiation. Some sources are consistent with stars of later spectral type, but not all can be. A number of maser sites show no detectable radio continuum emission associated with MIR emission, despite a powering source luminous enough potentially to produce an UC H ii region. Since no signs of an UC H ii region are detected here, these maser sites might be produced during a very early stage of stellar evolution. We present objects that show evidence of outflow activity stemming from a maser site, exhibiting CO and/or CS line profiles indicative of outflows coincident with the MIR source. These cases are promising examples of maser sites signposting the earliest stages of high-mass star formation. en_US
dc.identifier.issn 0035-8711 en_US
dc.language English
dc.language.iso EN en_US
dc.rights CC BY-NC-ND 3.0 en_US
dc.rights.uri en_US
dc.source Legacy MARC en_US
dc.title Mid-infrared observations of methanol maser sites and ultracompact H II regions: Signposts of high-mass star formation en_US
dc.type Journal Article en
dcterms.accessRights metadata only access
dspace.entity.type Publication en_US
unsw.identifier.doiPublisher en_US
unsw.relation.faculty Science
unsw.relation.ispartofjournal Monthly Notices of the Royal Astronomical Society en_US
unsw.relation.ispartofpagefrompageto 36-56 en_US
unsw.relation.ispartofvolume 326 en_US
unsw.relation.originalPublicationAffiliation Walsh, Andrew en_US
unsw.relation.originalPublicationAffiliation Bertoldi, F en_US
unsw.relation.originalPublicationAffiliation Burton, Michael, Physics, Faculty of Science, UNSW en_US
unsw.relation.originalPublicationAffiliation Nikola, Thomas en_US School of Physics *
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