Research activities of the High Energy Astrophysics Group at IoA/NTHU include high energy astrophysics related instrumentations, observations, and theoretical investigation.

Current on-going projects are described briefly in the following :

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The Nuclear Compton Telescope (NCT) Project
The NCT project is a joint effort of several institutions in Taiwan and in US. The NCT is a balloon-borne telescope designed to study astrophysical sources of MeV gamma-ray emission with high spectral resolution, moderate angular resolution, and novel sensitivity to gamma-ray polarization. The heart of NCT is an array of novel cross-strip germanium detectors, each of 15-mm thickness and 5400 mm^2 active area, with full 3D position resolution better than 2 mm^3. NCT will perform Compton imaging in the 0.2-10 MeV gamma-ray band. We are currently planning a 12-detector long duration balloon flight of the NCT instrument from Australia in December 2008. Major scientific topics of this project include the galactic 511-keV line emission, origin of Al-26, and polarization of gamma-ray emission from pulsars, etc.

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X-ray Occultation of Trans-Neptunian Objects (TNOs)
We have discovered, for the first time in astronomy, X-ray occultation events caused by TNOs. These events were found in the RXTE/PCA X-ray light curve of Sco X-1 at millisecond time scales. It opens up a new window for TNO surveys, particularly for the smallest, most abundant TNOs. The implication to the distribution of TNOs is being studied. It also provides a possible way of resolving the X-ray emitting region in compact stars with the technique of X-ray occultation.