Seminar by Naomi Tsuji, Kanagawa University
Since the recent detection of very-high-energy (E>1 TeV) gamma rays, microquasars have drawn more attention as potential PeVatron candidates. Among them, the microquasar SS 433 and its nebula W50 is a well known system. HAWC and HESS reported TeV gamma-ray emission from knot-like structures in the outer jets, likely powered by SS 433. This implies that particle acceleration takes place in the knots. More recently, LHAASO detected ultra-high-energy (E>100 TeV) gamma-ray emission from the northern part of SS 433, coinciding with a known HI cloud and thus suggesting hadronic origin. Motivated by these gamma-ray measurements, extensive X-ray and radio observation campaigns are currently underway. Especially, new Chandra observations on the western and eastern knots have been performed in 2023 and 2024. Combined with the archival data taken in 2000-2003, we can investigate proper motion and flux variation over 20-year interval. In this seminar, I will present preliminary results of these X-ray observations and recently conducted CO observations by the Nobeyama 45-m radio telescope.
Host: Jooyun Woo