Abstract
We present the results of a 6.7 GHz methanol maser survey from the Effelsberg 100 m radio telescope. A sample of 404 sources from the Bolocam Galactic Plane Survey (BGPS) 1.1 mm dust clump survey that met specific Galactic Legacy Infrared Mid-Plane Survey Extraodinaire (GLIMPSE) point-source color criteria was selected and 318 of these were observed. The new observations resulted in the detection of 29 methanol masers, including 12 new ones. Together with the additional 74 detections from the literature, this means that a total of 103 methanol masers are coincident with 1.1 mm dust clumps, yielding an overall detection rate of 26%. A comparison of the properties of a 1.1 mm dust clump and a 6.7 GHz methanol maser indicates that methanol masers with a higher flux density and/or luminosity are generally associated with more massive but less dense 1.1 mm dust clumps. The overall detection rate of 26% appears to vary as a function of the derived H-2 column density of the associated 1.1 mm dust clump. The methanol masers were primarily detected toward the brighter and more massive 1.1 mm dust clumps. A subsample of 194 sources that overlapped sources with observations of the 95 GHz methanol line was investigated in more detail for the properties of 1.1 mm dust clumps. The statistical analysis reveals that 1.1 mm dust clumps with both class I and II counterparts have much higher mean and median values of mass, column density, and flux density than those with only class I or II counterparts. Based on our much larger sample, we slightly revise the boundary defined previously for selecting BGPS sources associated with a class II methanol maser, wherein similar to 80% of expected class II methanol masers will be detected with a detection rate in the range of 40-50%.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.