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Hard x-ray observations of the extragalactic sky: the High Energy Focusing Telescope and the Serendipitous Extragalactic X-ray Source Identification survey


Mao, Peter Hsih-Jen (2002) Hard x-ray observations of the extragalactic sky: the High Energy Focusing Telescope and the Serendipitous Extragalactic X-ray Source Identification survey. Dissertation (Ph.D.), California Institute of Technology.


Extending the energy range of high sensitivity astronomical x-ray observations to the hard x-ray band (10--100 keV) is important for the study of nonthermal emission mechanisms and heavily obscured sources. This thesis, in two parts, describes the development of the High Energy Focusing Telescope (HEFT), a focusing telescope for the hard x-ray band, and the Serendipitous Extragalactic X-ray Source Identification (SEXSI) survey, a degree-scale x-ray/optical survey of sources detected in the Chandra hard band (2--7 keV). HEFT is a balloon-borne x-ray telescope that is expected to have its first flight in the fall of 2003. The telescope will be among the first to focus x-rays at energies greater than 20 keV. HEFT's mirrors use graded multilayers -- thin film coatings ($sim 1 mu$m) that enhance high energy reflectance via constructive interference. In the first half of the thesis, I describe the optimization algorithm that I developed for x-ray optics and how I applied this algorithm to the design of the HEFT optics. In addition, I present x-ray measurements that verify the HEFT multilayer coating designs at energies where the telescope will operate. The SEXSI survey complements Chandra deep-field surveys by covering a much larger area of the sky, but to a shallower x-ray flux limit. For the SEXSI survey, we use public data from the Chandra archive to compile a catalog of extragalactic sources detected in the 2--7 keV band. We identify the optical counterparts to the x-ray sources and obtain their optical spectra (400--1000 nm). Presently SEXSI includes 30 Chandra fields, covering roughly 2 square degrees and yielding over 1200 x-ray sources to a flux limit of $10^{-15}$--$10^{-13}$ ergflux. In the second part of the thesis, I present results from 10 fields for which we have substantial spectroscopic coverage.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:active galactic nuclei; cosmic x-ray background; massively parallel computing
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Harrison, Fiona A.
Group:Space Radiation Laboratory
Thesis Committee:
  • Harrison, Fiona A. (chair)
  • Readhead, Anthony C. S.
  • Blandford, Roger D.
  • Tombrello, Thomas A.
Defense Date:24 May 2002
Non-Caltech Author Email:peterm (AT)
Record Number:CaltechETD:etd-06132002-131531
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2567
Deposited By: Imported from ETD-db
Deposited On:04 Oct 2002
Last Modified:26 Sep 2014 18:30

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