Spatial Structure and Collisionless Electron Heating in Balmer-dominated Shocks

Abstract

Balmer-dominated shocks in supernova remnants (SNRs) produce strong hydrogen lines with a two-component profile composed of a narrow contribution from cold upstream hydrogen atoms, and a broad contribution from hydrogen atoms that have undergone charge transfer reactions with hot protons. Observations of emission lines from edge-wise shocks in SNRs can constrain the gas velocity and collisionless electron heating at the shock front. Downstream hydrogen atoms engage in charge transfer, excitation and ionization reactions, defining an interaction region called the shock transition zone. The properties of hot hydrogen atoms produced by charge transfers (called broad neutrals) are critical for accurately calculating the structure and radiation from the shock transition zone. This paper is the third in a series describing the kinetic, fluid and emission properties of Balmer-dominated shocks, and is the first to properly treat the effect of broad neutral kinetics on shock transition zone structure. We use our models to extract shock parameters from observations of Balmer-dominated SNRs. We find that inferred shock velocities and electron temperatures are lower than those of previous calculations by <10% for v_s<1500 km/s, and by 10-30% for v_s>1500 km/s. This effect is primarily due to the fact that excitation by proton collisions and charge transfer to excited levels favor the high speed part of the neutral hydrogen velocity distribution. Our results have a strong dependence on the ratio of electron to proton temperatures, β=T_e/T_p, which allows us to construct a relation β(v_s) between the temperature ratio and shock velocity. We compare our calculations to previous results by Ghavamian et al. (2007).

41 pages, 15 figures, 2 tables. Improved comparison to previous results, added discussion, and incorporated referee's suggestions. Submitted to ApJ

References in corpus (14)

• A Physical Relationship Between Electron-Proton Temperature Equilibration and Mach Number in Fast Collisionless Shocks
• Balmer-Dominated Spectra of Nonradiative Shocks in the Cygnus Loop, RCW 86 and Tycho Supernova Remnants
• The SN 1006 Remnant: Optical Proper Motions, Deep Imaging, Distance, and Brightness at Maximum
• The Optical Spectrum of the SN 1006 Supernova Remnant Revisited
• High Resolution Spectroscopy of Balmer-Dominated Shocks in the RCW 86, Kepler and SN 1006 Supernova Remnants
• Balmer-Dominated Shocks Revisited
• The Physics of Supernova Remnant Blast Waves. I. Kinematics of DEM L71 in the Large Magellanic Cloud
• SUBARU HDS Observations of a Balmer-Dominated Shock in Tycho's Supernova Remnant
• The pre-shock gas of SN1006 from HST/ACS observations
• The Detection of Far Ultraviolet Line Emission from Balmer-Dominated Supernova Remnants in the Large Magellanic Cloud
• Non-Maxwellian Proton Velocity Distributions in Nonradiative Shocks
• The Transition Zone in Balmer-Dominated Shocks
• Broad Lyman-Alpha Emission from Supernova Remnants in Young Galaxies
• A high resolution UV absorption spectrum of supernova ejecta in SN1006

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