Polarimetry in the ALMA era: a new crossroads of astrophysics
2019 March 26 (Tuesday) - March 29 (Friday)
National Astronomical Observatory of Japan (Mitaka, Tokyo, Japan)
Magnetic fields (B fields) are believed to play key roles in any astronomical objects, yielding common viewpoints when we analyses data obtained from observations and simulations. To understand roles of B fields, one must know both B-field structures and their strengths.
ALMA has offered opportunities to study the former towards compact sources, e.g., disks and jets around forming stars, by linear-polarization imaging. Despite limited capabilities as non-standard observations, polarization observations with ALMA are very suggestive. One of the important lessons is that one cannot naively transfer knowledge obtained from the polarimetry towards the low-density regions (e.g., molecular clouds) to the innermost high-density regions that ALMA can explore.
At the same time, it becomes clear that scientific outcome will be more fruitful if ALMA would enhance its wide-field polarization imaging capabilities and offer circular polarization detection capabilities. We also recognize importance to link single-dish polarimetric studies, e.g., using POL-2 at JCMT, with those by ALMA to shed light on the roles of B fields. This is simply because any interplay between self-gravity of gas and other forces by e.g., turbulence and B fields are multi spatial scale phenomena.