Probing Solar Chromospheric Temperatures and Dynamics with ALMA and IBIS"

Friday, 28 June 2019 9 a.m. — 10 a.m. MST

AURA Lecture Hall

NOIRLab South Colloquia
KEVIN REARDON (National Solar Observatory and NOAO South Visiting Astronomer)

Even after many decades of detailed study, many mysteries about the solar chromosphere remain. Making progress on these questions will be a key focus of solar physics in the coming years. In this talk, I will discuss recent work in this area combining imaging spectroscopy in the optical regime using the Interferometric Bidimensional Spectrometer (IBIS) and millimeter diagnostics from the Atacama Large Millimeter Array (ALMA). Using these instruments, we have new ways to probe the chromospheric temperature structure and dynamics on time scales of tens of seconds and spatial scales of a few 100 km. We find evidence that spectral-line parameters of H-alpha and Ca II are closely correlated with the ALMA brightness temperatures. I will explain how this changes our understanding of chromospheric dynamics and the interpretation of the observed spectral intensities. Finally, I will touch on the advances we expect on these questions from the soon-to-be-operational DKI Solar Telescope (DKIST).