(11/23/98) The headers of the files may be lengthy. To
avoid IRAF errors associated with the headers being too long, include
the following in your login.cl: set min_lenuserarea = 500000
 (11/23/98) In the Version-1 data (11/23/98) there is a
mismatch between the fluxes of the G430M spectrum and the G230L and
E230M spectra in the wavelength region from 3000 to 3200
Angstroms. This discrepancy is under investigation. In the meantime,
 (11/24/98) PSF distortion : The tilted Field Offset Mirror (FOM) position used for the NICMOS HDF-South imaging results in some distortion of the point spread function over the field of view. Caution should be exercised in any analysis requiring precise information about the PSF.
 (11/24/98) Linearity corrections : During the course
of HDF-South data reduction we identified problems with the standard
procedures used to correct nonlinearity in NICMOS images. A new
procedure was implemented for the F222M images (where the high thermal
background countrate makes linearity correction necessary) but has not
yet been applied to the F110W and F160W images. Moreover the new
procedure is based on a preliminary revision to the linearity
calibrations and has not yet been fully tested. It is unlikely that
these linearity corrections affect object photometry by more than a
few percent, i.e. the resulting uncertainties are probably smaller
than those of the absolute photometric zeropoints of the data (see
above). We will be investigating this in more detail in the near
 (11/23/98) The NICMOS Flanking Field data are still being processed. The final data products will be made available as soon as they are finished. Our current target date is mid-January 1999. Raw and calibrated data for individual datasets are already available from the HST Data Archive.
This page was last updated on December 23, 1998.