We present the first observation of a solar prominence at 84 − 116 GHz using the high resolution interferometric imaging of ALMA. Simultaneous observations in Hα from Białkaw Observatory and with SDO/AIA reveal similar prominence morphology to the ALMA observation. The contribution functions of 3 mm and Hα emission are shown to have significant overlap across a range of gas pressures. We estimate the maximum millimetre-continuum optical thickness to be τ3mm ≈ 2, and the brightness temperature from the observed Hα intensity. The brightness temperature measured by ALMA is ∼6000 − 7000 K in the prominence spine, which correlates well with the estimated brightness temperature for a kinetic temperature of 8000 K.
|Number of pages
|Monthly Notices of the Royal Astronomical Society: Letters
|Early online date
|7 Mar 2022
|Published - 11 Jun 2022