X-ray Astronomy with CCDs: Calibration of the Advanced CCD Imaging Spectrometer and Observations of Rotation-powered Pulsars

TL;DR

This dissertation details the calibration of the ACIS instrument on Chandra using synchrotron radiation and mesh techniques, and investigates X-ray properties of rotation-powered pulsars and supernova remnants to understand neutron star emission mechanisms.

Contribution

It introduces a novel mesh technique for non-destructive sub-pixel CCD measurement and provides comprehensive X-ray analysis of pulsars and supernova remnants using Chandra data.

Findings

Calibration parameters for CCD detection efficiency derived from synchrotron measurements

Discovery of a new point source in the supernova remnant Cas A

Insights into neutron star emission mechanisms from pulsar observations

Abstract

(ABRIDGED) This dissertation concerns the use of CCDs for for X-ray astronomy. Part I of this thesis focuses on the calibration of the Advanced CCD Imaging Spectrometer (ACIS), one of the two primary focal plane instruments on the Chandra X-ray Observatory. I begin by presenting a series of measurements made using undispersed synchrotron radiation. I analyzed the results of these experiments to extract parameters necessary to model the absolute detection efficiency of CCDs used as reference standards for ACIS characterization. I also discuss a novel "mesh" technique I pioneered to non-destructively measure the sub-pixel structure of CCDs, including the channel stops and gates. Guided by the results of the mesh experiments, I performed additional measurements to constrain recombination effects in the channel stops. Part II of this thesis concerns the X-ray properties of rotation- powered (radio) pulsars. High energy observations serve as a powerful diagnostic of the energetics and emission mechanisms of neutron stars. I analyze ASCA and ROSAT observations of three young pulsars which are particularly well-suited for addressing these issues. I also present observations of the rotation-powered pulsar with the highest known magnetic field, and describe how the results relate to anomalous X-ray pulsars, another type of neutron star. Finally, I analyze Chandra observations of the supernova remnant Cas A. These data fully demonstrate the capabilities of ACIS and reveal a previously unknown point source at the center of the remnant.