Observing the Sun with the ALMA: Polarization Observations at 3 mm

ABSTRACT :
Solar observations with ALMA using the Band3 and Band6 receivers have been offered since ALMA Cycle 4. After the start of solar observations, the development was continued and several new functions for solar observations were offered (Band5, Band7, and regional mapping with the TP array). Based on the results of the commissioning activity for non-solar full Stokes observations offered since ALMA Cycle7, we started the development of solar polarization observations in 2019. Finally, in October 2022, we obtained enough data for the solar polarization commissioning and confirmed the specifications of the solar polarization observations. Then, the ALMA observatory has provided solar polarization observations with the Band3 receivers since ALMA Cycle10. In this talk, I will present the scientific potential of millimeter solar polarization observations and the results of the solar polarization commissioning activities.