EDUCATION:

Ph.D. 1983, Columbia University
B.A.  1977, Cornell University

RESEARCH:

My research involves the development of novel instrumentation and experiments for balloon-borne and satellite-borne missions to investigate a variety of astrophysical phenomena.

We are currently involved in an experiment called the High Energy Focusing Telescope (HEFT). HEFT is the world's largest hard X-ray telescope experiment, operating in the 20-100 keV energy band, and HEFT is launched from a balloon. HEFT's first flight took place in spring of 2006, and it imaged a variety of sources including a young supernova with a neutron star at the center, a highly magnetized neutron star and a blazar – an extragalactic source with an ultra-massive black hole at its center. Analysis of this data set is ongoing, and several publications on this first flight are forthcoming. Of particular interest to the Columbia team is the spatial mapping of the hard X-ray emission from supernova remnants. Mapping of the radioactive Titanium ejected by young supernovae, through spectral lines detectable by HEFT, permits investigation of our fundamental understanding of stellar nucleosynthesis. The continuum hard X-rays emitted by young supernovae have been identified as sites of cosmic-ray acceleration, and mapping the spatial and spectral distribution of hard X-rays, produced in the same shocks as the cosmic-rays, provides a direct probe theories of the origin and acceleration of the cosmic-rays.  Subsequent flights of HEFT will make more detailed observations of Active Galactic Nuclei, and perform high sensitivity, high resolution imaging of the Galactic Center. The Galactic Center is the site of a large population of white dwarfs, neutron stars and black holes.  Columbia will place particular emphasis on analysis of data from the imaging of the Galactic Center. HEFT is a collaboration that includes CalTech, the Danish National Space Center and Lawrence Livermore National Laboratory. Columbia had overall responsibility for the optics, and graduate students and post-doctoral researchers at Columbia have been heavily involved in the fabrication and X-ray testing of the optics. In addition Columbia constructed the gondola, and has been involved in the development of the aspect reconstruction system. The optics exploited a novel approach to the construction of low cost, lightweight optics which was developed at Columbia. We are continually investigating concepts for future X-ray optics with the goal of producing telescopes of ever-increasing angular resolution, while simultaneously reducing their mass and cost.  Prototype telescopes will be tested on future flights of HEFT. We are also developing advanced X-ray optics for future space missions including Constellation-X, NASA's next major X-ray spectroscopy mission.

Another exciting area we have moved into is particle astrophysics, specifically the search for dark matter.  We are studying a radical new concept which enables sensitive searches for antimatter in space.  The detection of antimatter is an indirect signature of dark matter. Our approach is called GAPS – the general antiparticle spectrometer.  GAPS relies on the detection of characteristic X-rays and pions produced when antiparticles are captured into target atoms in excited states and consequently decay. The energy of the X-rays uniquely defines the mass of the captured particle. Specifically GAPS would search for antideuterons, which are produced in the annihilation of neutralinos and universal extra dimension Kaluza-Klein particles, and also in the evaporation of primordial black holes.  We have successfully tested a prototype GAPS in two experiments at the KEK particle accelerator in Japan and are currently designing an experiment to be deployed on a balloon in Antarctica at the end of the decade. GAPS will be developed from scratch, so there will be extensive laboratory work on detectors and electronics, simulations of expected signal and background signatures and studies of the fundamental physics to be extracted from the experiment.  In 2008, in conjunction with GAPS collaborators at the Japanese National Space Agency (JAXA), we will fly a prototype detector from the Sanriku launch facility in northern Japan.

We also exploit data from current X-ray satellite missions. I am particularly interested in neutron stars, and the composition of their atmospheres and interiors. We have developed new techniques for rapidly solving the Schrodinger equation in the ultra-high magnetic fields found in many neutron stars. Using data from the Chandra and Newton X-ray observatories and our atomic model, we have for the first time identified an isolated neutron star with a non-Hydrogenic atmosphere, in this case Oxygen and/or Neon. This discovery has important consequences for our understanding of neutron stars and their interiors, which we and others are investigating.


SELECTED PUBLICATIONS:

C.J. Hailey, T. Aramaki, W.W. Craig, F. Gahbauer, J.E. Koglin, L. Fabris, N. Madden, K. Mori, H.T. Yu, K.P. Ziock, "Accelerator Testing of the General Antiparticle Spectrometer, a Novel Approach to Indirect Dark Matter Detection," Journal of Cosmology and Astroparticle Physics, JCAP01, 007, 2006

J.E. Koglin, W.M. Baumgartner, C.M.H. Chen, J.C. Chonko, F.E. Christensen, W.W. Craig, T.R. Decker, C.J. Hailey, F.A. Harrison, C.P. Jensen, K.K. Madsen, M.J. Pivovaroff and G. Tajiri, "Calibration of HEFT Hard X-ray Optics," Proceedings of the X-ray Universe 2005," 955, 2006.

K. Mori and C. Hailey, "Detailed Atmosphere Modeling for the Neutron Star 1E1207.4-5209: Evidence of an Oxygen/Neon Atmosphere,"Astrophysical Journal, 648, 1139, 2006.

K. Mori, J. Chonko and C.J. Hailey, "Detailed Spectral Analysis of the 260 ksec XMM-Newton Data of 1E1207.4-5209 and Significance of a 2.1 keV Absorption Feature," Astrophysical Journal, 631, 1082, 2005. 

C.J. Hailey, F.E. Christensen, W.W. Craig, F.A. Harrison, J.E. Koglin, R. Petre, H.T. Yu and W.W. Zhang, "Fabrication and Performance of Constellation-X Hard X-ray Telescope Prototype Optics Using Segmented Glass," Proc. SPIE 5168, 90, 2004.

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