A new set of WFPC-2 mosaics are available courtesy of Mark Dickinson and Richard Hook. The World Coordinate System (WCS) keywords in the mosaics and in the IRIM data have been updated to match the system defined in Williams et al (1996, AJ, 112, 1335) based on radio interferometric positions for several HDF sources. An iraf script hdf_wcs_fix.cl is available to updated the header information in the version 2 drizzled images.
To make room for the mosaics, we have deleted the version-1 HST WFPC images from the archive disk. The v2 images (still available) should be better for most purposes. If (for some peculiar reason) you want the v1 images, you may request a tape from ferguson@stsci.edu.
Redshifts from the Caltech and Hawaii Keck runs have been added to the Caltech web page.
Astrometry of the HDF flanking fields has been carried out by the DEEP collaboration.
HDF version 3 has slowed considerably, mostly because it is not a high priority given the modest expected gains in resolution and S/N. The new target date is the end of the summer
A cautionary note on photometry. The zeropoints listed for the HDF do not include a correction for contamination, which progressively adds attenuation between monthly decontaminations (warmups) of WFPC-2. As the HDF was taken shortly after a DECON, this effect is less than 0.05 mag for F300W, and significantly less for the redder filters. The F300W correction will be posted here once it is computed.
A more serious concern is that the F300W exposures, which have low backgrounds and low source count rates, are in a regime where charge-transfer effects (CTE) could be significant. Measured magnitudes of faint sources in the F300W band could be up to 0.2 mag fainter than true magnitudes, with the size of the effect depending on row number. The effect is probably only a few hundredths of a mag for the optical filters because of their higher backgrounds. Laboratory tests and observations in Cycle 6 are being planned to try to arrive at a calibration of CTE as a function of row number, source count rate, background level, the number of counts in the previous image, and the time elapsed between images. Details of recent investigations of the CTE and (and a similar, probably related photometric dependence on exposure time) are posted on the WFPC-2 advisory page.
Added an update on J, H, and K band observations from the KPNO 4-m telescope.
Our new target date for version 3 of the data reduction is now the end of May.
Sky levels for the individual chips are now posted.