Lecturer: Dr. Sladjana Knezevic Affiliation: Weizmann Institute of Science Abstract: I will present high-resolution spectrophotometric imaging of Balmer- dominated shocks (BDSs) around two historical supernova remnants, SN1006 and Tycho. BDSs are characterized by strong hydrogen emission lines with a narrow (~10 km/s) and a broad (~ 1000 km/s) component. The emission originates very close to the shock front and provides several important diagnostics for the physical processes in fast collisionless shocks. The line shapes and their spatial profiles are used for studying shock precursors. Using integral-field spectroscopy and Fabry-Perot interferometry we spatially resolve the shock filaments and minimize the shock geometry contribution to Halpha-line profiles. In the case of SN1006, we find significant variations in broad line widths and broad-to-narrow line intensity ratios across the filament. In Tycho, our observations indicate an additional intermediate-width (~ 100 km/s) component and the narrow component typically broader than the maximally expected 20 km/s. Our data allow distinguishing between different shocks models, and we find evidences for cosmic-ray and fast-neutral precursors in SN1006 and Tycho. Application of state-of- the-art shock models that include non- thermal physics to the presented data are expected to provide important constraints on the shocks and hadronic cosmic ray properties. Additional details of the upcoming Astrophysics' seminars can be found on the following link. ‏האירוע הזה כולל שיחת וידאו ב-Google Hangouts. הצטרף: https://hangouts.google.com/hangouts/_/mail.huji.ac.il/astrophysics?hceid=bWFpbC5odWppLmFjLmlsX2c0czhydDlpcmhwZzRvdGNybWIzZGFqcjdvQGdyb3VwLmNhbGVuZGFyLmdvb2dsZS5jb20.h0sd4r7kluoa7vofeqkkv0mn60&hs=121