An ALMA Survey of Massive Star Forming Regions with Class II Methanol Masers

Sheng-Yuan Liu^1*, Yu-Nung Su¹, Eduard Vorobyov², Dominique Meyer³, Andrey Sobolev⁴, Xi Chen⁵, Hongzhi Yu⁴, Dmitry Ladeyschikov⁴, Aadi Krishna⁶, Wanying Huang⁷

¹ASIAA, Taiwan
²U. of Vienna, Switzerland
³Potsdam U., Germany
⁴Ural Federal U., Russian Federation
⁵SHAO, China
⁶Yale U., USA
⁷McGill U., Canada

* Presenter:Sheng-Yuan Liu, email:syliu@asiaa.sinica.edu.tw

There are growing evidences suggesting that, similar to those in low-mass young stellar objects, luminosity burst phenomena also occur in massive star forming cores. Observationally, there are further very compelling evidences implying the association between Class II methanol maser flaring events and the luminosity burst in massive star forming regions (MSFRs). Such luminosity bursts are plausibly related to variable accretions events not only in low mass but also in high mass star formation processes as hinted by numerical radiation hydrodynamic simulations. While monitoring observations of the 6.7GHz Class II CH3OH maser in MSFRs have been routinely conducted but there is a lack of a uniform database and coherent knowledge about their associated submillimeter continuum emission and molecular gas properties. With that in mind, we carried out in ALMA Cycle 8 and 9 a Band 6 and Band 7 survey toward 169 massive star forming sites associated with 6.7 GHz CH3OH masers with the main 12-m array and the ACA, respectively. I will present the initial results from the survey observations.

Keywords: Massive Star Formation, Accretion Burst, Methanol Maser