Description
X-ray emission is released by both the heated plasma and accelerated electrons in solar flares, making it an important diagnostic of the impulsive energy release. Through joint multi-instrumental X-ray observations of solar flares we can get better constraints on the observed emission and gaining a better understanding of the energy release. We present summary of the results from the first joint spectral analysis of X-ray emission from solar microflares jointly observed with the Nuclear Spectroscopic Telescope Array (NuSTAR) and Solar Orbiter/Spectrometer/Telescope for Imaging X-rays (STIX) and NuSTAR and the Solar X-ray Monitor (XSM). NuSTAR is a highly sensitive X-ray telescope that can directly image the Sun from 2.5 keV, providing imaging spectroscopy of microflares. XSM, on the other hand, provides a full-disk integrated spectra from 1.3 keV. Through joint XSM and NuSTAR observations we can get better constrains on the thermal emission thanks to XSM’s energy range and resolution, while still constraining any higher energy emission with NuSTAR. Furthermore, NuSTAR is able to provide imaging context on the observed X-ray emission which is not possible with XSM. STIX is an imaging spectrometer which uses indirect optics but has detectors capable of handling a wide range of solar X-ray fluxes from 4 to 150 keV. Joint NuSTAR and STIX observations allow us to observe brighter emission that cannot be detected by NuSTAR alone. Furthermore, STIX is orbiting the Sun, so combined with NuSTAR, we can get different viewing angles of solar X-ray emission, providing a clearer picture of the flare’s structure.
