Science-advisor
REGISTER info/FAQ
Login
username
password
     
forgot password?
register here
 
Research articles
  search articles
  reviews guidelines
  reviews
  articles index
My Pages
my alerts
  my messages
  my reviews
  my favorites
 
 
Stat
Members: 3645
Articles: 2'501'711
Articles rated: 2609

19 April 2024
 
  » arxiv » 1007.5131

 Article overview


Reversal of infall in SgrB2(M) revealed by Herschel/HIFI observations of HCN lines at THz frequencies
Rainer Rolffs ; Peter Schilke ; Claudia Comito ; E.A. Bergin ; F.F.S. van der Tak ; D.C. Lis ; S.-L. Qin ; K.M. Menten ; R. Guesten ; T.A. Bell ; G.A. Blake ; E. Caux ; C. Ceccarelli ; J. Cernicharo ; N.R. Crockett ; F. Daniel ; M.-L. Dubernet ; M. Emprechtinger ; P. Encrenaz ; M. Gerin ; T.F. Giesen ; J.R. Goicoechea ; P.F. Goldsmith ; H. Gupta ; E. Herbst ; C. Joblin ; D. Johnstone ; W.D. Langer ; W.D. Latter ; S.D. Lord ; S. Maret ; P.G. Martin ; G.J. Melnick ; P. Morris ; H.S.P. Mueller ; J.A. Murphy ; V. Ossenkopf ; J.C. Pearson ; M. Perault ; T.G. Phillips ; R. Plume ; S. Schlemmer ; J. Stutzki ; N. Trappe ; C. Vastel ; S. Wang ; H.W. Yorke ; S. Yu ; J. Zmuidzinas ; M.C. Diez-Gonzalez ; R. Bachiller ; J. Martin-Pintado ; W. Baechtold ; M. Olberg ; L.H. Nordh ; J.J. Gill ; G. Chattopadhyay ;
Date 29 Jul 2010
AbstractTo investigate the accretion and feedback processes in massive star formation, we analyze the shapes of emission lines from hot molecular cores, whose asymmetries trace infall and expansion motions. The high-mass star forming region SgrB2(M) was observed with Herschel/HIFI (HEXOS key project) in various lines of HCN and its isotopologues, complemented by APEX data. The observations are compared to spherically symmetric, centrally heated models with density power-law gradient and different velocity fields (infall or infall+expansion), using the radiative transfer code RATRAN. The HCN line profiles are asymmetric, with the emission peak shifting from blue to red with increasing J and decreasing line opacity (HCN to H$^{13}$CN). This is most evident in the HCN 12--11 line at 1062 GHz. These line shapes are reproduced by a model whose velocity field changes from infall in the outer part to expansion in the inner part. The qualitative reproduction of the HCN lines suggests that infall dominates in the colder, outer regions, but expansion dominates in the warmer, inner regions. We are thus witnessing the onset of feedback in massive star formation, starting to reverse the infall and finally disrupting the whole molecular cloud. To obtain our result, the THz lines uniquely covered by HIFI were critically important.
Source arXiv, 1007.5131
Services Forum | Review | PDF | Favorites   
 
Visitor rating: did you like this article? no 1   2   3   4   5   yes

No review found.
 Did you like this article?

This article or document is ...
important:
of broad interest:
readable:
new:
correct:
Global appreciation:

  Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.

browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)






ScienXe.org
» my Online CV
» Free


News, job offers and information for researchers and scientists:
home  |  contact  |  terms of use  |  sitemap
Copyright © 2005-2024 - Scimetrica