Thursday

Observations of the solar radiation continuum at millimetre wavelengths facilitate direct measurements of (brightness) temperatures in different chromospheric layers that are complementary to other chromospheric diagnostics and thus of large scientific value for studying the solar atmosphere. Since regular observations of the Sun with the Atacama Large Millimeter/sub-millimeter Array (ALMA) started five years ago, an increasing number of data sets have been produced. The challenges connected to constructing solar image sequences from these novel data resulted in the development of the Solar ALMA Pipeline (SoAP), which is one of the major products of the now concluding ERC-funded Solar ALMA project. Currently, the data produced with SoAP are used to construct the first version of the Solar ALMA Science Archive (SALSA) with the aim of providing science-ready ALMA data to solar physicists. So far, SALSA mostly contains high-cadence (1-2s) time series of millimetre continuum images for different receiver bands and solar targets.

After a brief introduction to the opportunities and challenges connected to observing the Sun with ALMA, examples of SALSA data and first scientific results regarding, e.g., the imprint of magnetic fields, propagating shock waves, and oscillations are presented. Finally, the diagnostic potential for the Sun and other stars and the future development of ALMA’s solar capabilities are discussed.