other query modes : |
Identifier query |
Coordinate query |
Criteria query |
Reference query |
Basic query |
Script submission |
TAP |
Output options |
Object types |
Help |
2004ApJS..153..523L - Astrophys. J., Suppl. Ser., 153, 523-543 (2004/August-0)
A survey for infall motions toward starless cores. III. CS (3-2) and DCO+ (2-1) observations.
LEE C.W., MYERS P.C. and PLUME R.
Abstract (from CDS):
The velocity shifts of the CS (3-2) and (2-1) lines with respect to N2H+ correlate well with each other and have similar distributions. This implies that, in many cores, systematic inward motions of gaseous material may occur over a range of density of at least a factor ∼4.
We identify 18 infall candidates based on observations of CS (3-2), CS (2-1), DCO+ (2-1) and N2H+ (1-0). The eight best candidates, L1355, L1498, L1521F, L1544, L158, L492, L694-2, and L1155C-1, each show at least four indications of infall asymmetry and no counterindications.
Fits of the spectra to a two-layer radiative transfer model in ten infall candidates suggest that the median effective line of sight speed of the inward-moving gas is ∼0.07 km.s–1 for CS (3-2) and ∼0.04 km.s–1 for CS (2-1). Considering that the optical depth obtained from the fits is usually smaller in CS (3-2) than in (2-1) line, this may imply that CS (3-2) usually traces inner denser gas in higher inward motions than CS (2-1). However, it is also possible that this conclusion is not representative of all starless core infall candidates, because of the statistically small number analyzed here. Further line observations will be useful to test this conclusion.
Abstract Copyright: ∼
Journal keyword(s): ISM: Globules - ISM: Kinematics and Dynamics - Stars: Formation
VizieR on-line data: <Available at CDS (J/ApJS/153/523): table1.dat>
Nomenclature: Tables 1-3: [LM99] LNNNNA, [LM99] LNNNNA-N, [LM99] LNNNN-A, [LM99] LNNNNAN, [LM99] BNNNA, [LM99] BNNN-N, [LM99] CB NNN, [LM99] CB NNN-N, [LM99] DC LLLl+BB, [LM99] DC LLLl+BB-N, [LM99] DC LLLl+BBb, [LM99] DC LLLl+BBb-N, [LM99] VNN, [LM99] VNN-N, [LM99] Ch NN, [LM99] VNN, [LM99] Ch NN-N, [LM99] Mu NN, [LM99] TMC NA, [LM99] TMC N-N, N=94+70+10.
Simbad objects: 137
To bookmark this query, right click on this link: simbad:2004ApJS..153..523L and select 'bookmark this link' or equivalent in the popup menu