High-resolution studies of charge exchange in supernova remnants with Magellan, XMM-Newton, and Micro-X

Abstract

Charge exchange, the semi-resonant transfer of an electron from a neutral atom to an excited state in an energetic ion, can occur in plasmas where energetic ions are incident on a cold, at least partially neutral gas. Supernova remnants, especially in the immediate shock region, provide conditions conducive to charge exchange. The emission from post charge-exchange ions as the captured electron cascades down to the ground state, can shed light on the physical conditions of the shock and the immediate post-shock material, providing an important tool for understanding supernova explosions and their aftermath. In the first half of this thesis, I study charge exchange in the galactic supernova remnant G296.1-0.5 in two energy bands: the optical and the X-ray. The optical study, performed using both imaging and high resolution spectroscopy from the IMACS instrument on the Magellan Baade Telescope at Las Campanas Observatory, seeks to identify 'Balmer-dominated shocks' in the remnant, which signal the occurrence of charge exchange between hot, postshock protons and colder neutral hydrogen in the environment. The X-ray study probes line ratios in dispersed spectral data obtained with XMM-Newton RGS from an X-ray lobe in the NW of the remnant to hunt for signatures of charge exchange. The dispersed data are degraded by the extended nature of the source, blurring emission lines and making precise measurements difficult. The focus of the second half of this thesis is Micro-X : a sounding rocket-borne X-ray telescope, utilizing an array of microcalorimeters to achieve high energy resolution for even extended sources. I describe the design and commissioning of the payload and the steps toward launch, which is anticipated in the spring of 2015.