| Presentation Title: | Revisiting the RHESSI X-ray Microflare Statistics |
| Author(s): | Iain Hannah, Kate Barton |
Abstract:
RHESSI observed 10,000s of X-ray microflares (i.e. A, B-class flares) finding similar behaviour as found in larger flares: active region flares with hard X-rays from accelerated non-thermal electrons as well as hot thermal X-ray emission (Christe et al. 2008, Hannah et al. 2008). Spectral analysis of these events (covering 2005-2007) managed to determine the thermal and non-thermal energetics of each microflare, how their properties related and the overall flare frequency distributions. Here we revisit the spectral analysis of those RHESSI microflares, investigating their X-ray spectra in the context of updated models - non-thermal (using thick and warm target models instead of photon-space broken power-laws) and thermal (using CHIANTI v10.1, instead of v5.2) - determining the properties and energetics of these microflares. This has been done not only using OSPEX/SSWIDL (as was done in the original analysis) but also in the new Python package sunkit-spex (https://github.com/sunpy/sunkit-spex), with comparison made between the two. This work is also put in the context of more recent X-ray microflare observations from instruments like NuSTAR and STIX on Solar Orbiter.