SCYON Abstract

Received on November 23 2001

Deconvolution of ``drizzled'' and rotated HST/WFPC2 images: Faint-object photometry in crowded fields

Authors	Raymond F. Butler, Aaron Golden, Andrew Shearer
Affiliation	National University of Ireland, Galway, Ireland University Road, Galway, Ireland
To appear in	ASP Conf. Ser. Vol. 238, Proceedings of "Astronomical Data Analysis Software and Systems X", eds. F. R. Harnden, Jr., F. A. Primini, & H. E. Payne
Contact	ray@physics.nuigalway.ie
URL	http://www.it.nuigalway.ie/resear/papers/index.html
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Abstract

We have further adapted our deconvolution-based HST/WFPC2 reduction techniques, which our simulations have shown to be very effective in crowded fields (Butler 2000), to take advantage of the extra resolution afforded by ``dithered'' observations. This appears to be the first attempt at non-linear restorations of data which had already been sub-sampled and combined in a linear manner using the STSDAS/drizzle software, thus attaining a net subsampling factor of 4 x 4. The motivation was a search for the optical counterpart of the millisecond pulsar PSR B1821-24 in the globular cluster M28; the technique is illustrated by our photometric search for candidates in the radio-derived error circle, in archival HST/WFPC2 images in both the F555W & F814W bands of the core field of M28.