Mopra observations of G305.2+0.2: massive star formation at different evolutionary stages?
Walsh, A.J., and Burton, M.G. (2006) Mopra observations of G305.2+0.2: massive star formation at different evolutionary stages? Monthly Notices of the Royal Astronomical Society, 365 (1). pp. 321-326.
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We have successfully used a new on-the-fly mapping technique with the Mopra radio telescope to image G305.2+0.2 in transitions of 13CO, HCO+, N2H+, CH3CN and CH3OH. All these species appear to be concentrated towards the infrared-quiet methanol maser site G305A (G305.21+0.21). We suggest that this region contains an extremely deeply embedded site of massive star formation, with comparable qualities to the low-mass Class 0 stage. The infrared bright methanol maser site G305B (G305.21+0.20) also exhibits emission in all the mapped transitions, but always at a lower level.We suggest this is because it harbours a site of massive star formation older and more developed than G305.21+0.21. All transitions appear to be extended beyond the size of the Mopra beam (30 arcsec). 13CO and HCO+ line wings are suggestive of an outflow in the region, but the spatial resolution of these data is insufficient to identify the powering source. A narrow-lined (1.6 km s−1 compared to a typical line FWHM of 6.4 km s−1) N2H+ source (G305SW) is found 90 arcsec to the south-west of the main star-forming centres, which does not correspond to any CH3CN or CH3OH source, nor does it correspond well to 13CO or HCO+ emission in the vicinity.We suggest this may be a massive, cold, quiescent and possibly pre-stellar core.
|Item Type:||Article (Refereed Research - C1)|
|Keywords:||masers; stars; formation; ISM; molecules; infrared:|
|FoR Codes:||02 PHYSICAL SCIENCES > 0201 Astronomical and Space Sciences > 020104 Galactic Astronomy @ 100%|
|SEO Codes:||97 EXPANDING KNOWLEDGE > 970102 Expanding Knowledge in the Physical Sciences @ 100%|
|Deposited On:||18 Mar 2010 10:40|
|Last Modified:||13 May 2013 01:07|
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|Citation Counts with External Providers:||Web of Science: 11|
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