| Presentation Title: | NuSTAR observations of quiet Sun phenomena |
| Author(s): | Sarah Paterson, Iain Hannah, Brian Grefenstette, Kristopher Cooper, Hugh Hudson, Sam Krucker, Lindsay Glesener, David Smith, Stephen White7 |
Abstract:
We present a unique set of observations from the recent solar minimum (2018-2020) of the quiet-Sun using The Nuclear Spectroscopic Telescope Array, NuSTAR. This sensitive hard X-ray telescope provides for the first-time imaging spectroscopy > 2keV of quiet Sun phenomena like bright points (in a quiescent and flaring states), emerging flux regions, jet, minifilament eruptions and network/quiet Sun "flares". These types of features have previously been studied in softer X-rays and EUV, typically finding 1-3MK emission. NuSTAR X-ray spectra enables investigation of hotter (> 5MK) and possible non-thermal emission, which are expected if these small impulsive releases of energy are “flare-like” and contribute significantly to heating the Sun’s atmosphere. Combining the NuSTAR X-ray data with softer X-ray images from Hinode/XRT and EUV observations from SDO/AIA we can investigate the spatial and temporal evolution of these faint features and calculate the differential emission measure to study their multi-thermal behaviour. We present an overview of some of the quiet Sun features detected by NuSTAR from different campaigns during solar minimum. This work has so far been published in Paterson et al. Sol Phy 298 (2023) and Paterson et al. MNRAS 528 (2024).