Invited Presentation

Magnetic field and Fragmentation at 0.1 to 0.01 pc scale

Author(s): Ya-Wen Tang

Presenter: Ya-Wen Tang (ASIAA)

With the ALMA online, it becomes possible to obtain high angular resolution (0.1") and sensitive polarization images in a large sample within a reasonable timescale.
The science which the SMA can do and is unique at the moment is to probe the polarization in extended structures.
In this talk, I will present our complimentary SMA project to the existing ALMA polarization survey, in which we study the fragmentation levels and the B-field at 0.3" resolution in 22 high mass star forming regions.
The science questions we try to address are:
1: At 0.1 pc scale, is there a systematic difference in the energy balance among gravity, turbulence and B field which possibly explains the observed different distributions of cores and the multiplicity of fragmentation seen at 0.01 pc scale?
2: What are the relative orientation of the B-field at a 0.1pc
scale with respect to the dominant structure (i.e. the major axis of the dense clump)? Are they aligned with the fragments seen at 0.01 pc scale?
I will present our preliminary results and discuss on how magnetic field regulates the fragmentation between 0.01 and 0.1 pc scale based on these observational results.