2013A&A...550A..21S


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.08CEST15:01:37

2013A&A...550A..21S - Astronomy and Astrophysics, volume 550A, 21-21 (2013/2-1)

Different evolutionary stages in massive star formation. Centimeter continuum and H2O maser emission with ATCA.

SANCHEZ-MONGE A., BELTRAN M.T., CESARONI R., FONTANI F., BRAND J., MOLINARI S., TESTI L. and BURTON M.

Abstract (from CDS):

We present Australia Telescope Compact Array (ATCA) observations of the H2O maser line and radio continuum at 18.0GHz and 22.8GHz toward a sample of 192 massive star-forming regions containing several clumps already imaged at 1.2mm. The main aim of this study is to investigate the water maser and centimeter continuum emission (that likely traces thermal free-free emission) in sources at different evolutionary stages, using evolutionary classifications previously published. We used the recently comissioned Compact Array Broadband Backend (CABB) at ATCA that obtains images with ∼20" resolution in the 1.3cm continuum and H2O maser emission in all targets. For the evolutionary analysis of the sources we used millimeter continuum emission from the literature and the infrared emission from the MSX Point Source Catalog. We detect centimeter continuum emission in 88% of the observed fields with a typical rms noise level of 0.45mJy/beam. Most of the fields show a single radio continuum source, while in 20% of them we identify multiple components. A total of 214cm continuum sources have been identified, that likely trace optically thin HII regions, with physical parameters typical of both extended and compact HII regions. Water maser emission was detected in 41% of the regions, resulting in a total of 85 distinct components. The low angular (∼20") and spectral (∼14km/s) resolutions do not allow a proper analysis of the water maser emission, but suffice to investigate its association with the continuum sources. We have also studied the detection rate of HII regions in the two types of IRAS sources defined in the literature on the basis of the IRAS colors: High and Low. No significant differences are found, with high detection rates (>90%) for both High and Low sources. We classify the millimeter and infrared sources in our fields in three evolutionary stages following the scheme presented previously: (Type 1) millimeter-only sources, (Type 2) millimeter plus infrared sources, (Type 3) infrared-only sources. We find that HII regions are mainly associated with Type 2 and Type 3 objects, confirming that these are more evolved than Type 1 sources. The HII regions associated with Type 3 sources are slightly less dense and larger in size than those associated with Type 2 sources, as expected if the HII region expands as it evolves, and Type 3 objects are older than Type 2 objects. The maser emission is mostly found to be associated with Type 1 and Type 2 sources, with a higher detection rate toward Type 2, consistent with the results of the literature. Finally, our results on HII region and H2O maser association with different evolutionary types confirm the evolutionary classification proposed previously.

Abstract Copyright:

Journal keyword(s): stars: formation - stars: massive - HII regions - radio continuum: ISM - masers

VizieR on-line data: <Available at CDS (J/A+A/550/A21): obs.dat cm.dat masers.dat hii.dat type1.dat type2.dat type3.dat>

Status at CDS:   All or part of tables of objects could be ingested in SIMBAD with priority 2.

CDS comments: Note 3 Several calibrators not found.

Simbad objects: 11

goto Full paper

goto View the reference in ADS

Number of rows : 11

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 QSO B0537-441 BLL 05 38 50.36155219 -44 05 08.9389165   15.77 16.48 16   ~ 786 2
2 QSO B0826-373 QSO 08 28 04.78022012 -37 31 06.2809892   16       ~ 42 0
3 ICRF J100614.0-501813 QSO 10 06 14.00931618 -50 18 13.4706757   20.78       ~ 24 0
4 NAME VLBI 1323-527 QSO 13 26 49.2298147073 -52 56 23.634693653           ~ 48 3
5 ICRF J151141.2+051809 Sy1 15 11 41.26654675 +05 18 09.2597600   18.49 17.80 13.95   ~ 82 0
6 3FGL J1617.4-5846 AGN 16 17 17.8913859288 -58 48 07.860059063   18.23       ~ 89 1
7 QSO J1713-2658 QSO 17 13 31.27558558 -26 58 52.5264855   19.65       ~ 32 1
8 ICRF J171736.0-334208 BLL 17 17 36.02909328 -33 42 08.8248676   20.93   17.3   ~ 91 1
9 QSO B1830-211 QSO 18 33 39.92 -21 03 39.9     18.70 21   ~ 549 6
10 ICRF J192559.6+210626 QSO 19 25 59.60535560 +21 06 26.1620442           ~ 177 1
11 ICRF J193925.0-634245 Sy2 19 39 25.02671 -63 42 45.6255   18.87 18.37 17.64   ~ 953 1

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2013A&A...550A..21S and select 'bookmark this link' or equivalent in the popup menu


2020.07.08-15:01:37

© Université de Strasbourg/CNRS

    • Contact