Introduction
Current X-ray telescopes achieve an angular resolution of 0.5 arcseconds at best, obscuring any detailed structure of X-ray binaries and Active Galactic Nuclei (AGN) etc. AGNs have been studied in all wavelengths but the mechanism of excessive energy emission in its core is still not well understood. A supermassive black hole is believed to be present at the core. More resolved X-ray observations can provide insights on the evolution of AGNs and provide better constraints on the physical properties of the supermassive black hole.
Future planned telescopes will fare even worse as photon collection is preferred over resolution. To achieve a higher angular resolution without an unacceptably large penalty in photon collection, the XOSS project proposes a large occulting satellite to be used in combination with existing or future telescopes. With a modified eclipse mapping method algorithm written by Starkman and Copi, we can improve signal-to-background ratio and increase image resolution to the order of sub-arcseconds.
Our computer simulations have proven the technique to be a success with filaments and a point source (see Experiment section). We have also constructed a physical, scaled-down model in comparison to the future X-ray telescope Constellation-X. We selected Constellation-X because it has the advantage 4 detectors instead of one. With multiple detectors, we can simultaneously observe an object with and without occultation to eliminate any natural fluctation of the source intensity for the reconstruction process. Currently we are testing the image reconstruction algorithm written by Starkman and Copi with a 1mCi Cs-137 radioactive source in different configurations. Preliminary reconstructed image can be seen in the Experiment section.
XOSS at Case
Currently Corbin Covault and members of the Experimental High Energy Astrophysics Group are working in close collaboration with Glenn Starkman and Craig Copi of the Particle Astrophysics Theory Group to explore the prospects and performance potential of the XOSS concept in future X-ray missions, specifically Constellation-X.
NASA artists conception of the Constellation-X project
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