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Charles J. Hailey
Ph.D., Columbia University
B.A., Cornell University
My research focuses on observational high energy astrophysics and experimental particle astrophysics.
In high energy astrophysics my group is part of the NuSTAR Galactic Plane Survey working group, which I chair. Our research focuses on the Galactic Center and its immediate environs. We use both NuSTAR and other X-ray observatories such as Chandra, XMM/Newton and Swift to study X-ray sources in the central ~100 pc, Using NuSTAR we discovered the central hard X-ray emission (CHXE), the unresolved emission of 1000s of magnetized white dwarf binaries. The CHXE dominates the X-ray emission in the Galactic Center above 10 keV and within 10 parsec of the supermassive black hole. Using the Chandra X-ray Observatory we recently discovered a dozen sources - predominantly black hole binaries, in the central parsec. These sources confirm the existence of a density cusp of massive compact objects in the Galactic Center, and from our observations we could infer the existence of 1000s of isolated black holes in the central parsec of the Galaxy. In conjunction with the VERITAS and HAWC teams, we are using NuSTAR to observe unidentified TeV sources detected by HAWC in our Galaxy. The combination of NuSTAR, HAWC and VERITAS spectroscopy and imaging allows us to constrain models for the emission of TeV gamma-rays from these sources, the most energetic gamma-ray emitters in the Galaxy.
I am also the principal investigator of a balloon-borne experiment to hunt for dark matter - The General Antiparticle Spectrometer Experiment - GAPS- will search for cosmic antideuterons and antiprotons. Many beyond-the Standard-Model theories postulate weakly interacting massive particles (WIMPS) that can annihilate in WIMP-WIMP interactions in the galactic halo. The antideuterons are produced as a rare byproduct of these annihilations, and potentially offer a smoking gun signature of dark matter. In many beyond-the-Standard-Model theories, antideuteron searches offer the most sensitive means to detect dark matter. In addition, GAPS should be sensitive to cosmic-ray anti-Helium, as recently reported by the AMS collaboration. GAPS uses a novel scheme to detect antimatter through identification of atomic deexcitation X-rays and particles produced when antimatter is captured in an atom and subsequently annihilates in the nucleus. Columbia has been working with collaborators at MIT and in Japan to develop the X-ray/particle detectors used in GAPS, and the detectors will be tested and assembled at Columbia, and all the experiment subsystems will be assembled at Columbia. A prototype experiment was successfully flow from Hokkaido, Japan in June 2012. The full science experiment, which involves about a dozen US and international partners in Italy and Japan, will fly from Antarctica in late 2020.
C.J. Hailey et al., "A Density Cusp of Quiescent X-ray Binaries in the Central Parsec of the Galaxy," Nature, 556, 70, 2018.
K. Perez et al., "Fabrication of Low-cost, Large-area Prototype Si(Li) Detectors for the GAPS Experiment," Nuclear Instruments and Methods, A905, 21, 2018.
C.J. Hailey et. al., "Evidence for Intermediate Polars as the Origin of the Galactic Center X-ray Emission," Astrophysical Journal, 826, 160, 2016.
T. Aramaki et. al., "Antideuteron Sensitivity of the GAPS Experiment," Astroparticle Physics, 74, 6, 2016.
K. Perez et. al., "Extended Hard X-ray Emission in the Inner Few Parsecs of the Galaxy," Nature, 520, 646, 2015.
T. Aramaki et.al, “Potential for Precision Measurement of Low-Energy Antiprotons with GAPS for Dark Matter and Primordial Black Hole Physics,” Astroparticle Physics 59, 12, 2014.
P. von Doetinchem et. al., “The Flight of the GAPS Prototype Experiment,” Astroparticle Physics, 54, 93, 2014.
K. Mori et. al., “NuSTAR Discovery of a 3.76-second transient magnetar near Sagittarius A*,” Astrophysical Journal, 770, L23, 2013.