2012A&A...541A..32F


C.D.S. - SIMBAD4 rel 1.7 - 2020.10.30CET03:28:25

2012A&A...541A..32F - Astronomy and Astrophysics, volume 541A, 32-32 (2012/5-1)

Temperature and kinematics of protoclusters with intermediate and high-mass stars: the case of IRAS 05345+3157.

FONTANI F., CASELLI P., ZHANG Q., BRAND J., BUSQUET G. and PALAU A.

Abstract (from CDS):

Improving our understanding of the complex star formation process in clusters requires studies of star-forming clouds to search for dependencies of the physical properties on environmental variables, such as overall density, stellar crowding and feedback from massive (proto-)stars. We aim to map at small spatial scales the temperature and the velocity field in the protocluster associated with IRAS 05345+3157, which contains both intermediate-/high-mass protostellar candidates and starless condensations, and is thus an excellent location to investigate the role of massive protostars on protocluster evolution. We observed the ammonia (1, 1) and (2, 2) inversion transitions with the VLA. Ammonia is the best thermometer for dense and cold gas, and the observed transitions have critical densities able to trace the kinematics of the intracluster gaseous medium. The ammonia emission is extended and distributed in two filamentary structures. The starless condensations are colder than the star-forming cores, but the gas temperature across the whole protocluster is higher (by a factor of 1.3-1.5) than that measured typically in both infrared dark clouds and low-mass protoclusters. The non-thermal contribution to the observed line broadening is at least a factor of 2 larger than the expected thermal broadening even in starless condensations, contrary to the close-to-thermal line widths measured in low-mass quiescent dense cores. The NH3/N2H+ abundance ratio is greatly enhanced (a factor of 10) in the pre-stellar core candidates, probably due to freeze-out of most molecular species heavier than He. The more massive and evolved objects likely play a dominant role in the physical properties and kinematics of the protocluster. The high level of turbulence and the fact that the measured core masses are larger than the expected thermal Jeans masses indicate that turbulence likely was an important factor in the initial fragmentation of the parental clump and can provide support against further fragmentation of the cores.

Abstract Copyright:

Journal keyword(s): stars: formation - radio lines: ISM - ISM: individual objects: IRAS 05345+3157 - ISM: kinematics and dynamics - ISM: molecules

Nomenclature: Table 1: [FCZ2012] AN (Nos A1-A2).

Simbad objects: 24

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Number of rows : 24

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 3C 48 QSO 01 37 41.2995845985 +33 09 35.079126038   16.62 16.20     ~ 2526 2
2 3C 84 Sy2 03 19 48.1597607660 +41 30 42.114155434   13.10 12.48 11.09   ~ 3582 3
3 NAME Perseus Cloud SFR 03 35.0 +31 13           ~ 1086 0
4 NAME [BM89] B5 DNe 03 47 38.3 +32 52 43           ~ 221 0
5 LDN 1471 DNe 03 48.0 +32 54           ~ 282 0
6 LDN 1544 DNe 05 04 16.6 +25 10 48           ~ 703 0
7 NAME [BM89] L1544 cor 05 04 22.5 +25 11 36           ~ 434 1
8 NGC 1985 RNe 05 37 47.8 +31 59 24           ~ 130 2
9 [FCZ2012] A1 cor 05 37 51.0 +32 00 10           ~ 1 0
10 [FCB2008] C1-b cor 05 37 52.17 +32 00 04.0           ~ 3 0
11 [FCB2008] C1-a cor 05 37 52.27 +32 00 06.0           ~ 4 0
12 [FCB2008] C4 cor 05 37 52.5 +31 59 45           ~ 4 0
13 [LLK2011] Core 4 cor 05 37 52.5 +32 00 04           ~ 5 0
14 [FCZ2012] A2 cor 05 37 53.0 +31 59 45           ~ 1 0
15 [FCB2008] C2 cor 05 37 53.0 +31 59 59           ~ 5 0
16 [LLK2011] Core 1 cor 05 37 53.03 +31 59 34.9           ~ 4 0
17 [FCB2008] S cor 05 37 53.2 +31 59 50           ~ 3 0
18 [FCB2008] N cor 05 37 53.3 +32 00 14           ~ 3 0
19 7C 055201.39+394824.00 QSO 05 55 30.80561150 +39 48 49.1649664     18.0 17.5   ~ 468 2
20 3C 286 Sy1 13 31 08.2885060664 +30 30 32.960825108   17.51 17.25     ~ 3777 1
21 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3067 0
22 NAME the Pipe Nebula DNe 17 30 -25.0           ~ 339 1
23 NAME Dragon Nebula DNe 18 42 50.6 -04 03 30           ~ 114 0
24 IRAS 20293+3952 HII 20 31 11.040 +40 03 10.69           ~ 67 0

    Equat.    Gal    SGal    Ecl

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2020.10.30-03:28:25

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