Archival Pure Parallels Project (APPP)

The Archival Pure Parallel Project has processed with state-of-the-art tools 9136 WFPC2 images, primarily in the wide UBVI filters, obtained in parallel with other HST instruments. We produced combined, drizzled, cosmic-ray cleaned images for each pointing. These data can be used to address a wide range of science topics: measuring the cosmic shear on scales from 20 arcsec to 2 arcmin; discovering ~ 50 starforming galaxies at z ~ 4; finding optical counterparts to AGNs in wide-area radio and X-ray catalogs; improving the determination of the scale length of the Galactic disk; and studying stellar populations down to 1 solar mass for about 25 separate lines of sight in the Magellanic Clouds. We have delivered a total of 2481 science images and associated weight files to the MAST archive. These images cover 1743 distinct pointings on the sky with a combined on-sky exposure time of about 7.8 million seconds. These images are being made available to the astronomical community for a wide variety of other investigations, thus helping realize the legacy of WFPC2 parallel images.

Check the project proposal for details on the project as it was proposed. The details of the processing pipeline are described in a paper published in the PASP.

The v2.0 data can be searched and downloaded via the APPP data page on MAST. You may also download the data via anonymous ftp by ftping to and then cd /pub/hlsp/appp . The data are stored in subdirectories by pointing name under the subdirectories lmc, smc, nbg, fnd, ffd, tfd and sfd. The README contains a high level description of the data.