2002A&A...390..289B


C.D.S. - SIMBAD4 rel 1.7 - 2021.03.02CET03:20:21

2002A&A...390..289B - Astronomy and Astrophysics, volume 390, 289-298 (2002/7-4)

CH3OH and H2O masers in high-mass star-forming regions.

BEUTHER H., WALSH A., SCHILKE P., SRIDHARAN T.K., MENTEN K.M. and WYROWSKI F.

Abstract (from CDS):

We present a comparison of Class ii CH3OH (6.7GHz) and H2O (22.2GHz) masers at high spatial resolution in a sample of 29 massive star-forming regions. Absolute positions of both maser types are compared with mm dust continuum, cm continuum and mid-infrared sources. All maser features - regardless of the species - are associated with massive mm cores, but only 3 out of 18 CH3OH masers and 6 out of 22 H2O masers are associated with cm emission likely indicating the presence of a recently ignited massive star. These observations of a homogenous sample of massive, young star-forming regions confirm earlier results, obtained for each maser species separately, that both maser types are signposts of high-mass star formation in very early evolutionary stages. The data are consistent with models that explain CH3OH maser emission by radiative pumping in moderately hot cores, requiring the absence, or only weak, free-free cm continuum radiation due to recently ignited stars. Mid-infrared sources are associated with both maser types in approximately 60% of the observed fields. Thus, mid-infrared objects may power maser sites, but the detection of strong mid-infrared emission is not strictly necessary because it might be heavily extincted. A comparison of the spatial separations between the different observed quantities and other properties of the star-forming regions does not reveal any correlation. Our data suggest that CH3OH and H2O masers need a similar environment (dense and warm molecular gas), but that, due to the different excitation processes (radiative pumping for CH3OH and collisional pumping for H2O), no spatial correlations exist. Spatial associations are probably coincidences due to insufficient angular resolution and projection effects. The kinematic structures we find in the different maser species show no recognizable pattern, and we cannot draw firm conclusions as to whether the features are produced in disks, outflows or expanding shock waves.

Abstract Copyright:

Journal keyword(s): masers - stars: formation - ISM: dust, extinction - ISM: jets and outflows - infrared: ISM - continuum: ISM radio

Nomenclature: Table 2: [BWS2002] JHHMMSS.s+DDMMSS.s N=26+43.

Simbad objects: 33

goto Full paper

goto View the reference in ADS

Number of rows : 33

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 W 3(H2O) Mas 02 27 04.6 +61 52 25           ~ 124 0
2 NAME SH 2-233 IR Cl* 05 39 10.4 +35 45 19           ~ 93 0
3 IRAS 05358+3543 mul 05 39 10.4 +35 45 19           ~ 137 1
4 GRS G012.89 +00.49 HII 18 11 51.3 -17 31 29           ~ 149 0
5 IRAS 18090-1832 Y*O 18 12 01.88616 -18 31 55.5636           ~ 64 0
6 IRAS 18102-1800 HII 18 13 12.2 -17 59 35           ~ 23 0
7 IRAS 18151-1208 Y*O 18 17 58.114 -12 07 24.84           ~ 101 0
8 IRAS 18182-1433 mul 18 21 07.9 -14 31 53           ~ 97 0
9 OH 16.59 -0.05 cor 18 21 09.2137 -14 31 45.484           ~ 118 0
10 IRAS 18264-1152 cor 18 29 14.6846 -11 50 23.966           ~ 73 1
11 GAL 022.357+00.066 HII 18 31 44.9 -09 22 09           ~ 40 0
12 IRAS 18306-0835 cor 18 33 23.8651 -08 33 24.197           ~ 39 0
13 IRAS 18308-0841 HII 18 33 32.89 -08 39 18.5           ~ 31 0
14 IRAS 18310-0825 HII 18 33 47.9 -08 23 52           ~ 30 0
15 IRAS 18345-0641 cor 18 37 17.4520 -06 38 30.992           ~ 42 0
16 [AAJ2015] G026.594-00.026 HII 18 39 55.9 -05 38 45           ~ 31 1
17 IRAS 18385-0512 cor 18 41 13.7583 -05 08 55.892           ~ 49 1
18 IRAS 18440-0148 cor 18 46 36.56 -01 45 21.2           ~ 55 0
19 SSTGLMC G032.990+00.040 HII 18 51 24.8 +00 04 19           ~ 31 0
20 IRAS 18521+0134 cor 18 54 40.76 +01 38 05.0           ~ 27 0
21 IRAS 18553+0414 cor 18 57 53.37 +04 18 15.7           ~ 28 0
22 IRAS 18566+0408 cor 18 59 10.3479 +04 12 18.220           ~ 122 1
23 IRAS 19012+0536 cor 19 03 46.0583 +05 40 43.552           ~ 50 1
24 IRAS 19035+0641 Y*O 19 06 01.63416 +06 46 36.6168           ~ 56 0
25 IRAS 19217+1651 cor 19 23 58.77 +16 57 44.8           ~ 32 0
26 IRAS 19282+1814 HII 19 30 28.1 +18 20 53           ~ 36 0
27 MSX6C G059.7831+00.0648 Y*O 19 43 11.21664 +23 44 03.9696           ~ 130 0
28 IRAS 19410+2336 SFR 19 43 11.5 +23 44 06           ~ 143 0
29 IRAS 20126+4104 Y*O 20 14 25.8816186803 +41 13 36.869078243           B2.5-B0.5 403 0
30 IRAS 20293+3952 HII 20 31 11.040 +40 03 10.69           ~ 68 0
31 IRAS 23033+5951 Y*O 23 05 25.16112 +60 08 15.4428           ~ 80 0
32 IRAS 23139+5939 Y*O 23 16 10.39680 +59 55 28.2396           ~ 77 0
33 IRAS 23151+5912 HII 23 17 21.0 +59 28 49           ~ 93 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2002A&A...390..289B and select 'bookmark this link' or equivalent in the popup menu


2021.03.02-03:20:21

© Université de Strasbourg/CNRS

    • Contact