Tram Le Ngoc
Max-Planck-Institut für Radioastronomie
Study magnetic fields and dust physics with airborne observatories
Magnetic field is believed to play an important role in the star formation process. Dust polarization induced by aligned dust grains is widely used to study magnetic fields in the different regions from the diffuse medium to star-forming regions. A popular theory of grain alignment is based on RAdiative Torques (RATs). Recently, suprathermal rotation of dust by RATs is found to induce rotational disruption of large grains into small fragments, which modifies the grain size distribution and affect the dust extinction, emission, and polarization properties. Thus, thermal dust polarization also allows us to study fundamental dust physics (alignment and disruption) and dust properties. Moreover, the gradient of gas velocity can also be used to probe the magnetic fields via velocity gradient technique (VGT). Therefore, the high spatial and spectral resolution of line tracers with SOFIA/(up)GREAT opens a new avenue for the VGT technique. In this talk, we will present the recent development of the theory of the grain alignment and disruption by RATs to interpret the polarimetric observations toward molecular w/o embedded sources and PDR regions and the applications to the Airborne SOFIA/HAWC+ and BLASTPol measurements. We will also introduce the recent work on combining the SOFIA/GREAT and SOFIA/HAWC+ to understand the interplay between the gas kinematic and magnetic fields.