IACHEC 2020/2021 Pandemic Report

Understand

In this report we summarize the activities of the International Astronomical Consortium for High Energy Calibration (IACHEC) and the work done since the last in-person meeting in Japan (Shonan Village Center), May 2019, through two virtual meetings that were held in November 2020 and May 2021.

• The on-line only meetings divided the contents of the usual in-person workshop between mission updates and working group updates.
• The November meeting was dedicated to mission calibration updates and the current status of the cross-calibration between NuSTAR, Swift, and NICER, which frequently join together in observations of bright transients, and a review of the XMM-Newton and Chandra cross-calibration.
• Results between \nustar\ and \swift\ overall show good agreement, but issues persist in the overlap region 3--5 keV for bright source with large dust scattering halos.