NOAO >   Observing Info >   Approved Programs >   2014A-0307

Proposal Information for 2014A-0307

PI: P. Frank Winkler, Middlebury College, winkler@middlebury.edu
Address: Department of Physics, Bicentennial Hall, Middlebury, VT 05753, USA

CoI: Knox S. Long, STScI
CoI: John C. Raymond, Harvard-Smithsonian CfA

Title: Fast SNR Shocks and Cosmic Rays: Unique Opportunities in SN 1006

Abstract: We propose to explore the fundamental physics of nonradiative shocks and cosmic ray acceleration through GMOS images and spectra of optical filaments in \sn that we have recently identified in deep \ha images. Previous studies have concentrated on the NW rim where the optical emission is brightest, but this results from anomalously high pre-shock density and is not typical of \sn. Our new observations show that faint Balmer filaments surround virtually the entire periphery, including the NE and SW portions where hard X-ray and (gamma)-ray emission indicates that electrons are being accelerated to TeV energies. Ions are almost certainly accelerated in these same regions, to produce cosmic rays. From the profiles of the broad Balmer lines in the new spectra, we will measure the temperature T_p of hot post-shock protons and obtain a definitive measurement of the fraction of shock energy converted into cosmic rays. Our new \ha images also show several filaments that appear to be bowshocks formed immediately ahead of ejecta-dominated X- ray knots seen in a deep mosaic of \sn we have obtained with \em Chandra. Bullets" of ejecta must have penetrated to the outer shock, where they are interacting with partially neutral ISM to produce these Balmer bowshocks. For the bowshock filaments, we will measure both the proper motion (from our new images), and the line profiles, to give the shock velocity and T_p. These provide a unique opportunity to explore effects of shock obliquity and curvature on particle acceleration efficiency.

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 NOAO >   Observing Info >   Approved Programs >   2014A-0307