We investigate how to achieve the best possible ACIS spatial resolution by binning in ACIS sub-pixel and applying an event repositioning algorithm after removing pixel-randomization from the pipeline data. We quantitatively assess the improvement in spatial resolution by (1) measuring point source sizes and (2) detecting faint point sources. The size of a bright (but no pile-up), on-axis point source can be reduced by 20-30%. With the improved resolution, we detect ∼20% more faint sources when embedded in the extended, diffuse emission in a crowded field. We further discuss the false source rate of ∼10% among the newly detected sources, using a few ultra-deep observations.
Astronomical Data Analysis Software and Systems XX
- Pub Date:
- July 2011