X-ray Telescopes: Development, Flight and Analysis
Abstract
This thesis is divided into three parts as themes of the same general subject: the X-ray focusing telescopes.
On the 18'th of May 2005 the balloon borne High Energy Focusing Telescope, HEFT, was launched on its maiden voyage from Fort Sumner, New Mexico. For 24 hours the gondola remained afloat proving that it could successfully track and detect the galactic X-ray sources, Cygnus X-1 and the Crab, before plunging to a hard and brutal landing in the desert. In this thesis I describe the HEFT gondola platform, designed and build by LLNL to hold the HEFT payload, and discuss the sensor groups available for pointing, their performance and accuracy. I also outline the pointing strategy we adopted, and describe how the sensors worked in concert to achieve the required pointing stability. Based on the gondola configuration I present the aspect reconstruction procedures and use them to show a first data analysis of the HEFT flight observations of the Crab and Cygnus X-1. In the second part of my thesis I present a method of simulating concept study designs of grazing incidence focusing X-ray telescopes used on the X-ray Evolving Universe Spectroscopy Mission, XEUS. Past and current X-ray missions have used single films of gold, platinum or iridium coatings, utilizing the critical angle to achieve high grazing incidence reflection. These coatings are, however, not efficient at energies above 20 keV. A method of pushing up the energy is by employing multilayers, or supermirrors, which is a stack of films of alternating low and high density material. Using a Figure of Merit code I step through a limited parameter space and find the optimal multilayer recipe that yields the best reflectivity for a given telescope design. This tool can be used to study the effects of different design parameters such as material selection and substrate thickness. In the third part I analyze data of the QSO B1152+199 taken with the Chandra x-ray observatory. I present evidence of variability in the lightcurve of the lens, which is accompanied by movement in the Fe Kα line emitting region. A sudden redshift or broadening of the iron line is an indication of strong gravitational effects. These effects are commonly seen in conjunction with a brightening or hardening of the source, as part of the accretion disc momentarily lights up, and can be used to constrain the parameters of the central black hole. I show there is a correlation between the lightcurve and movement of the iron line, and fit the spectrum with relativistic line model kyrline from xspec.- Publication:
-
Ph.D. Thesis
- Pub Date:
- April 2007
- Bibcode:
- 2007PhDT.......447K