For Swift, Markwardt oversees the activities of the Goddard BAT group, including the 15-150 keV hard X-ray survey and long term monitoring light curves in that band. For NICER, he leads both the calibration and science data task areas. Markwardt implemented the NICER pre-launch and in-flight calibration efforts. In addition, Markwardt designed and implemented the ground science software tools and data processing pipeline, which delivers thousands of completed NICER observations to the HEASARC archive per year.
He first worked with Jean Swank of the RXTE PCA project, on the studies of X-ray binaries. He has studied millisecond X-ray pulsars, accreting black hole microquasars, and has performed long term monitoring of the galactic center with the PCA instrument. Since 2001, he as also worked on the development and flight of the BAT instrument aboard the Swift gamma-ray burst mission. In addition to developing ground software for burst work, Markwardt has been using BAT survey data, both to continue X-ray binary work, and to search for faint active galactic nuclei. In 2009, Markwardt joined the GEMS project team and is excited to open a new frontier in the systematic study of X-ray polarimetry.