2010MNRAS.408.2426R -
Mon. Not. R. Astron. Soc., 408, 2426-2441 (2010/November-2)
Investigating the effects of chemistry on molecular line profiles of infalling low-mass cores.
ROBERTS J.F., RAWLINGS J.M.C. and STACE H.A.
Abstract (from CDS):
We have coupled a chemical model with two dynamical models of collapsing low-mass star-forming cores to predict abundances across the core of the commonly used infall tracers, CS and HCO+, at various stages of the collapse. The models investigated are a new ambipolar diffusion model and the `inside-out' collapse model. We then used these results as an input to a radiative transfer model to predict the line profiles of several transitions of these molecules. For the inside-out collapse model, we predict significant molecular depletion due to freeze-out in the core centre, which prevents the formation of the blue asymmetry (believed to be the `signature' of infall) in the line profiles. Molecular depletion also occurs in the ambipolar diffusion model during the late stages of collapse, but the line profiles still exhibit a strong blue asymmetry due to extended infall. For the inside-out collapse model to exhibit the blue asymmetry, it is necessary to impose a negative kinetic temperature gradient on the core and suppress freeze-out. Since freeze-out is observed in several class 0 protostars which are thought to be collapsing, this presents a major inconsistency in the inside-out collapse model of star formation.
Abstract Copyright:
© 2010 The Authors. Journal compilation © 2010 RAS
Journal keyword(s):
astrochemistry - line: profiles - stars: formation - ISM: molecules
Simbad objects:
9
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2010MNRAS.408.2426R and select 'bookmark this link' or equivalent in the popup menu