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arXiv · astro-ph/9601016

A Survey of the Galactic Plane for 6.7-GHz Methanol Masers I: l = 325.0 - 335.0 ; b = -0.53 - 0.53

S. P. Ellingsen·M. L. von Bibra·P. M. McCulloch·R. P. Norris·A. A. Deshpande·C. J. Phillips
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Abstract

We report the results of the first complete survey of an area of the Galactic Plane for maser emission from the 6.7-GHz transition of methanol. The survey covers a 10.6-square-degree region of the Galactic Plane in the longitude range 325-335 degrees and latitude range -0.53-0.53 degrees. The survey is sensitive to masers with a peak flux density greater than approximately 2.6 Jy. The weakest maser detected has a peak flux density of 2.3 Jy and the strongest a peak flux density of 425 Jy. We detected a total of 50 distinct masers, 26 of which are new detections. We show that many 6.7-GHz methanol masers are not associated with IRAS sources, and that some are associated with sources that have colours differing from those of a typical ultra-compact HII region (UCHII). We estimate that the number of UCHII regions in the Galaxy is significantly more than suggested by IRAS-based estimates, possibly by more than a factor of two.

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S. P. Ellingsen, M. L. von Bibra, P. M. McCulloch, R. P. Norris, A. A. Deshpande, C. J. Phillips. 1996-01-05. A Survey of the Galactic Plane for 6.7-GHz Methanol Masers I: l = 325.0 - 335.0 ; b = -0.53 - 0.53. https://doi.org/10.1093/mnras%2F280.2.378

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