dc.contributor.author | Gledhill, T. | |
dc.contributor.author | Forde, K.P. | |
dc.contributor.author | Lowe, Krispian | |
dc.contributor.author | Smith, M.D. | |
dc.date.accessioned | 2016-03-03T10:23:07Z | |
dc.date.available | 2016-03-03T10:23:07Z | |
dc.date.issued | 2011 | |
dc.identifier.citation | Gledhill , T , Forde , K P , Lowe , K & Smith , M D 2011 , ' Integral field spectroscopy of H-2 and CO emission in IRAS 18276-1431 : evidence for ongoing post-AGB mass-loss ' , Monthly Notices of the Royal Astronomical Society , vol. 411 , no. 3 , pp. 1453-1466 . https://doi.org/10.1111/j.1365-2966.2010.17779.x | |
dc.identifier.issn | 0035-8711 | |
dc.identifier.other | ORCID: /0000-0002-2859-4600/work/30779759 | |
dc.identifier.uri | http://hdl.handle.net/2299/16607 | |
dc.description | The definitive version can be found at: http://www.wiley.com/ Copyright Wiley Blackwell | |
dc.description.abstract | We present K-band integral field spectroscopy of the bipolar post-asymptotic giant branch (post-AGB) object IRAS 18276-1431 (OH 17.7-2.0) using SINFONI on the VLT. This allows us to image both the continuum and molecular features in this object from 1.95 to 2.45 mu m with a spatial resolution down to 70 mas and a spectral resolution of similar to 5000. We detect a range of H-2 rovibrational emission lines which are consistent with shock excitation in regions of dense (similar to 10(7) cm(-3)) gas with shock velocities in the range of 25-30 km s(-1). The distribution of H-2 emission in the bipolar lobes suggests that a fast wind is impinging on material in the cavity walls and tips. H-2 emission is also seen along a line of sight close to the obscured star as well as in the equatorial region to either side of the stellar position which has the appearance of a ring with radius 0.3 arcsec. This latter feature may be radially cospatial with the boundary between the AGB and post-AGB winds. The first overtone (CO)-C-12 bandheads are observed longward of 2.29 mu m with the v = 2-0 bandhead prominently in emission. The CO emission has the same spatial distribution as the K-band continuum and therefore originates from an unresolved central source close to the star. We interpret this as evidence for ongoing mass-loss in this object. This conclusion is further supported by a rising K-band continuum indicating the presence of warm dust close to the star, possibly down to the condensation radius. The redshifted scattered peak of the CO bandhead is used to estimate a dust velocity along the bipolar axis of 95 km s(-1) for the collimated wind. This places a lower limit of similar to 125 yr on the age of the bipolar cavities, meaning that the collimated fast wind turned on very soon after the cessation of AGB mass-loss. | en |
dc.format.extent | 565951 | |
dc.language.iso | eng | |
dc.relation.ispartof | Monthly Notices of the Royal Astronomical Society | |
dc.subject | shock waves | |
dc.subject | stars: AGB and post-AGB | |
dc.subject | circumstellar matter | |
dc.subject | stars: evolution | |
dc.subject | stars: individual: IRAS 18276-1431 | |
dc.subject | stars: individual: OH 17.7-2.0 | |
dc.title | Integral field spectroscopy of H-2 and CO emission in IRAS 18276-1431 : evidence for ongoing post-AGB mass-loss | en |
dc.contributor.institution | School of Physics, Astronomy and Mathematics | |
dc.contributor.institution | Science & Technology Research Institute | |
dc.contributor.institution | Centre for Astrophysics Research | |
dc.description.status | Peer reviewed | |
dc.date.embargoedUntil | 2011-09-01 | |
rioxxterms.versionofrecord | 10.1111/j.1365-2966.2010.17779.x | |
rioxxterms.type | Journal Article/Review | |
herts.preservation.rarelyaccessed | true | |