Sökning: onr:"swepub:oai:DiVA.org:su-20158" >
The Distribution of...
-
Schöier, FredrikStockholms universitet,Institutionen för astronomi
(författare)
The Distribution of SiO in the Circumstellar Envelope around IRC +10216
- Artikel/kapitelEngelska2006
Förlag, utgivningsår, omfång ...
-
American Astronomical Society,2006
-
printrdacarrier
Nummerbeteckningar
-
LIBRIS-ID:oai:DiVA.org:su-20158
-
https://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-20158URI
-
https://doi.org/10.1086/506199DOI
Kompletterande språkuppgifter
-
Språk:engelska
-
Sammanfattning på:engelska
Ingår i deldatabas
Klassifikation
-
Ämneskategori:ref swepub-contenttype
-
Ämneskategori:art swepub-publicationtype
Anmärkningar
-
New interferometric observations of SiO J=5-->4 circumstellar line emission around the carbon star IRC +10216 using the Submillimeter Array are presented. Complemented by multitransition single-dish observations, including infrared observations of rovibrational transitions, detailed radiative transfer modeling suggests that the fractional abundance of SiO in the inner part of the envelope, between ~3 and 8 stellar radii, is as high as ~1.5×10-6. This is more than an order of magnitude higher than predicted by equilibrium stellar atmosphere chemistry in a carbon-rich environment and indicative of the importance of non-LTE chemical processes. In addition to the compact component, a spatially more extended (re~2.4×1016 cm) low fractional abundance (f0~1.7×10-7) region is required to fit the observations. This suggests that the majority of the SiO molecules are effectively accreted onto dust grains in the inner wind, while the remaining gas-phase molecules are eventually photodissociated at larger distances. Evidence of departure from a smooth wind is found in the observed visibilities, indicative of density variations of a factor 2-5 on an angular scale corresponding to a timescale of about 200 yr. In addition, constraints on the velocity structure of the wind are obtained.
Ämnesord och genrebeteckningar
Biuppslag (personer, institutioner, konferenser, titlar ...)
-
Fong, David
(författare)
-
Olofsson, HansStockholms universitet,Institutionen för astronomi(Swepub:su)olofs
(författare)
-
Zhang, Qizhou
(författare)
-
Patel, Nimesh
(författare)
-
Stockholms universitetInstitutionen för astronomi
(creator_code:org_t)
Sammanhörande titlar
-
Ingår i:The Astrophysical Journal: American Astronomical Society649:2, s. 965-9720004-637X1538-4357
Internetlänk
Hitta via bibliotek
Till lärosätets databas