High resolution spectroscopy of Balmer-dominated shocks in the RCW 86, Kepler and SN 1006 supernova remnants^*

¹ Stockholm Observatory, Department of Astronomy, AlbaNova, 106 91 Stockholm, Sweden
² Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Rd., Piscataway, NJ 08854-8019, USA
³ Visiting Astronomer, Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatories, CTIO is operated by AURA, Inc. under contract to the National Science Foundation
⁴ Cerro Tololo Inter-American Observatory, Casilla 603, Chile

Corresponding author: J. Sollerman, jesper@astro.su.se

Received: 25 March 2003
Accepted: 22 May 2003

Abstract

We report results from high resolution optical spectroscopy of three non-radiative galactic supernova remnants, RCW 86, Kepler's supernova remnant and SN 1006. We have measured the narrow component Hα line widths in Balmer-dominated filaments in RCW 86 and SN 1006, as well as the narrow component width in a Balmer-dominated knot in Kepler's SNR. The narrow component line widths measured in RCW 86 and Kepler's SNR show FWHM of  km s^-1, similar to what has been seen in other Balmer-dominated remnants. Of the remnants in our sample, SN 1006 is the fastest shock (~3000 km s^-1). The narrow component Hα and Hβ lines in this remnant have a FWHM of merely 21 km s^-1. Comparing the narrow component widths measured in our sample with those measured in other remnants shows that the width of the narrow component does not correlate in a simple way with the shock velocity. The implications for the pre-heating mechanism responsible for the observed line widths are discussed.