2020A&A...640L...6C


C.D.S. - SIMBAD4 rel 1.7 - 2020.10.26CET14:01:34

2020A&A...640L...6C - Astronomy and Astrophysics, volume 640, L6-6 (2020/8-1)

Ubiquitous NH3 supersonic component in L1688 coherent cores.

CHOUDHURY S., PINEDA J.E., CASELLI P., GINSBURG A., OFFNER S.S.R., ROSOLOWSKY E., FRIESEN R.K., ALVES F.O., CHACON-TANARRO A., PUNANOVA A., REDAELLI E., KIRK H., MYERS P.C., MARTIN P.G., SHIRLEY Y., CHUN-YUAN CHEN M., GOODMAN A.A. and DI FRANCESCO J.

Abstract (from CDS):


Context. Star formation takes place in cold dense cores in molecular clouds. Earlier observations have found that dense cores exhibit subsonic non-thermal velocity dispersions. In contrast, CO observations show that the ambient large-scale cloud is warmer and has supersonic velocity dispersions.
Aims. We aim to study the ammonia (NH3) molecular line profiles with exquisite sensitivity towards the coherent cores in L1688 in order to study their kinematical properties in unprecedented detail.
Methods. We used NH3 (1,1) and (2,2) data from the first data release (DR1) in the Green Bank Ammonia Survey (GAS). We first smoothed the data to a larger beam of 1' to obtain substantially more extended maps of velocity dispersion and kinetic temperature, compared to the DR1 maps. We then identified the coherent cores in the cloud and analysed the averaged line profiles towards the cores.
Results. For the first time, we detected a faint (mean NH3(1,1) peak brightness <0.25K in TMB), supersonic component towards all the coherent cores in L1688. We fitted two components, one broad and one narrow, and derived the kinetic temperature and velocity dispersion of each component. The broad components towards all cores have supersonic linewidths (MS≥1). This component biases the estimate of the narrow dense core component's velocity dispersion by ≃28% and the kinetic temperature by ≃10%, on average, as compared to the results from single-component fits.
Conclusions. Neglecting this ubiquitous presence of a broad component towards all coherent cores causes the typical single-component fit to overestimate the temperature and velocity dispersion. This affects the derived detailed physical structure and stability of the cores estimated from NH3 observations.

Abstract Copyright: © S. Choudhury et al. 2020

Journal keyword(s): ISM: kinematics and dynamics - ISM: molecules - stars: formation - ISM: individual objects: L1688, Ophiuchus

Simbad objects: 22

goto Full paper

goto View the reference in ADS

Number of rows : 22

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 NGC 1333 OpC 03 29 11 +31 18.6           ~ 1231 1
2 NAME Perseus Cloud SFR 03 35.0 +31 13           ~ 1086 0
3 NAME [BM89] B5 DNe 03 47 38.3 +32 52 43           ~ 221 0
4 Barnard 18 Cld 04 31.2 +24 21           ~ 48 0
5 NAME Taurus Complex SFR 04 41.0 +25 52           ~ 3545 0
6 NAME f-Shaped Filament in Orion Cld 05 35.0 -05 30           ~ 68 0
7 NAME rho Oph A Cloud MoC 16 26 26.4 -24 22 33           ~ 241 1
8 [DAM2004] Oph A-N2 PoC 16 26 26.5 -24 22 24           ~ 2 0
9 [DAM2004] Oph A-N6 cor 16 26 31.6 -24 24 52           ~ 16 0
10 NAME rho Oph C Cloud MoC 16 26 53.1 -24 32 31           ~ 57 0
11 NAME rho Oph E MoC 16 27 02.0 -24 38 31           ~ 56 0
12 NAME rho Oph Cloud B1 PoC 16 27 10.5 -24 29 30           ~ 51 1
13 NAME rho Oph B3 Cloud MoC 16 27 20 -24 24.5           ~ 8 1
14 NAME rho Oph B2 Cloud PoC 16 27 27.9 -24 26 29           ~ 75 1
15 NAME rho Oph F MoC 16 27 37.3 -24 42 28           ~ 58 0
16 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3066 0
17 [CPG2019] L1688-d10 cor 16 28 22.12 -24 36 16.8           ~ 3 0
18 NAME Ophiuchus D MoC 16 28 29.2 -24 18 25           ~ 105 0
19 [MAN98] I-MM1 mm 16 28 57.70 -24 20 33.7           ~ 6 0
20 [CPG2019] L1688-d12 cor 16 28 59.99 -24 20 45.2           ~ 3 0
21 NAME Serpens Cloud SFR 18 29 49 +01 14.8           ~ 927 2
22 NAME Gould Belt PoG ~ ~           ~ 724 1

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2020A&A...640L...6C and select 'bookmark this link' or equivalent in the popup menu


2020.10.26-14:01:34

© Université de Strasbourg/CNRS

    • Contact