NOAO >   Observing Info >   Approved Programs >   2014A-0366

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Proposal Information for 2014A-0366


PI: Jong-Ho Shinn, Korea Astronomy and Space Science Institute, jhshinn@kasi.re.kr
Address: South Korea

CoI: Melvin Hoare, University of Leeds
CoI: Stuart Lumsden, University of Leeds

Title: Study on the accretion of massive young stellar objects using the outflow features around ultracompact H II regions

Abstract: The formation process of massive stars (M > 8 Ms) is still unclear in many aspects. One topic is the accretion process of massive young stellar objects (MYSO). The infalling material must lose its angular momentum to be accreted onto the central object. If not, the angular momentum is piled up on the central object, and it would rotate ever-increasing velocity. The outflow enables the removal of angular momentum, and hence it visualizes the accretion history. By investigating these “footprint” outflow features around “late-stage” MYSO, we can study the accretion process of MYSO. Such outflow features were imaged in [Fe II] 1.64 um around the “late-stage” MYSO, known as ultracompact H II region (UCHII). However, the low imaging resolution ( 0.8”) limits detailed study of accretion process. Here we propose imaging observations of seven selected UCHIIs in [Fe II] 1.64 um, J, H, and K, with NIRI equipped with ALTAIR LGS AO, expecting the imaging resolution of 0.1”. These data would help to clarify the accretion process of MYSO, e.g. the outflow morphology (jet-like or wide-open), the outflow mass loss rate, the stellar content and multiplicity of the target UCHII, etc.


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NOAO >   Observing Info >   Approved Programs >   2014A-0366

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