H2O Masers in the Galactic Plane. I. Longitude 340º to the Galactic Centre

Caswell, J. L.; Batchelor, R.; Forster, J. R.; Wellington, K. J.

doi:10.1071/ph830401b

Cited by 28 publications

(20 citation statements)

References 2 publications

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“…The radial velocity of the non-masing transitions fall in the range -16 to -12.4 km s −1 . Maser emission was also observed (Caswell et al 1983;Gaume & Mutel 1987;Caswell 1997Caswell , 2003and Caswell et al 1995) toward the ultracompact Hii region of RCW 122 C.…”

Section: Introductionmentioning

confidence: 87%

Molecular gas associated with RCW 121 and RCW 122

Arnal

Duronea

Testori

2008

A&A

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Aims. We analyse the distribution of the molecular gas towards the region containing the open cluster Havlen-Moffat 1 (HM 1) the Wolf-Rayet stars WR 87, WR 89, and WR 91, and the star forming regions RCW 121 and RCW 122, with the aim of looking for a possible physical relationship among these objects. Methods. We used the carbon monoxide observations carried out at λ ∼ 2.6 mm with the 4 m NANTEN radiotelescope; new flux density determinations derived from already existing radio continuum surveys at 2. 417, 5, 8.35, and 14.35 GHz; continuum flux density determinations available in the literature; and the Midcourse Space Experiment (MSX) and the Improved Reprocessing of the IRAS Survey (IRIS) databases. Results. Adopting a distance of 5 kpc for RCW 121 and RCW 122, we found a giant molecular cloud (GMC) with a linear extent of ∼100 × 20 pc to be associated with galactic star-forming regions. The total mass of this GMC is of the order of 1.2 × 10 6 solar masses and its mean radial velocity is about -15 km s −1 . Within the GMC there are individual molecular gas concentrations, having total molecular masses in the range from 4.6 × 10 4 M (RCW 122 C) to 2.2 × 10 5 M (RCW 122). The CO profiles observed toward the peak of the molecular concentrations are broad, with typical full-width half-maximum around 6 to 7 km s −1 , and show line asymmetries and/or double-peaked shape that change with the observed position within a given CO concentration. An analysis of the MSX and IRAS databases show that each CO concentration has a strong IR counterpart. The dust temperature of these concentrations range from 46 K (RCW 121) to 76 K (RCW 122 C). Their infrared luminosity are a few times 10 5 L . The new radio continuum flux density determinations are in good agreement with previous determinations at other frequencies, and confirm the thermal nature of RCW 121 and RCW 122. Based on the newly-determined 5 GHz flux density, we found that to power these Hii regions, each of them must harbour a sizable number of O type stars. Under the assumption that all the ionizing stars have a O7 V spectral type, at least ∼8 and ∼4 of these stars would be needed to ionize RCW 122 and RCW 121, respectively.

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Section: Introductionmentioning

confidence: 87%

Molecular gas associated with RCW 121 and RCW 122

Arnal

Duronea

Testori

2008

A&A

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“…It has OH and H 2 O associated masers (Batchelor et al 1980;Caswell et al 1983), making it a classical high mass star formation region. IRAS 15437-5343 shows colours of an UCHII region and appears deeply embedded (high optical depth τ ν ∼ 100).…”

Section: 12+051mentioning

confidence: 99%

First SIMBA observations towards CH$_\mathsf{3}$OH masers

Pestalozzi

Humphreys

Booth

2002

A&A

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Abstract. We report SIMBA 1.2 mm dust continuum observations of the environments of eight methanol maser sources, all discovered during spatially fully-sampled, untargeted surveys of the galactic plane. We summarise our search for possible associations of the masers with IR sources (IRAS and MSX) and find that it is not always possible to make definite associations. A preliminary characterisation of the IR sources found in the maser neighbourhood is given according to their position in the [60-25]-[25-12] colour-colour diagram.

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“…The next three columns list the galacto-centric distance, distance from the Sun as determined from the observed CS velocity, and the height et al (1978) 6 Simpson et al (1990), 7 Testi et al (1994), 8 Zavagno et al (1992). Maser references: a) Batchelor et al (1980), b) Braz & Scalise (1982), c) Braz et al (1989), d) Caswell et al (1983), e) Forster & Caswell (1989), f) Güsten & Downes (1983), g) Kaufmann et al (1977), h) Moran & Rodriguez (1980), i) Scalise & Braz (1980), j) Scalise et al (1989). † Velocity of an OH maser.…”

Section: Source Listmentioning

confidence: 99%

Studies of dense molecular cores in regions of massive star formation. IV. Multitransition CS-study towards

Juvela

1996

Astron. Astrophys. Suppl. Ser.

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Abstract. -We have observed CS and C 34 S emission towards 33 H2O maser positions in the southern sky (δ < −28• ) using the SEST telescope. Most of the sources were selected also for their association with strong IRAS sources. CS(2−1) was detected in all sources, with the possible exception of two. Most sources were also mapped in the transitions CS(5−4) and C 34 S(2−1) and half of the sample also in CS(2−1). CS and C 34 S transitions J = 2 − 1, J = 3 − 2 J = 5 − 4 were measured towards the centres of the clouds as determined from the mapping. CS and C 34 S transitions J = 7− 6 were measured in about a half dozen clouds. CO(1−0) was measured in most clouds in order to determine the kinetic temperatures. The CS column densities were calculated using the LTE approximation. All measurements were also analyzed using a spherical LVG model. We present the observational data and the results of this analysis.

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H2O Masers in the Galactic Plane. I. Longitude 340º to the Galactic Centre

Cited by 28 publications

References 2 publications

Molecular gas associated with RCW 121 and RCW 122

Molecular gas associated with RCW 121 and RCW 122

First SIMBA observations towards CH$_\mathsf{3}$OH masers

Studies of dense molecular cores in regions of massive star formation. IV. Multitransition CS-study towards

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