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HDF-S Warnings and Advisories
STScI logoThe Hubble Deep Field South

Warnings and Advisories

Information is available for the following topics:


General

[2] (11/29/98) When browsing through this web site, always use RELOAD on your browser to make sure you get the latest version of a page, rather than an older version that still exists in the cache.

[1] (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


STIS Spectroscopy

[2] (11/24/98)In the Version-1 data (11/23/98) there was an error in the G230L wavelength scale, introduced in the last step of the data reduction. This was corrected in version 1b, released December 21, 1998.

[1] (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, caveat emptor.


STIS Imaging

[1] (11/23/98) Please read the section on the window reflection before trying to identify or analyze objects close to the quasar!


WFPC2


NICMOS

[3] (11/24/98) Photometric zeropoints :There remains some significant uncertainty in the absolute photometric calibration of the NICMOS HDF-South images, with zeropoints for some bands uncertain at roughly the 10% level. Please read the discussion of NICMOS photometric zeropoints for further information. USERS WHO REQUIRE ABSOLUTE PHOTOMETRY BETTER THAN 10% IN THE NICMOS DATA SHOULD PROCEED WITH CAUTION BECAUSE OF THESE UNCERTAINTIES. We will provide updated information on photometric zeropoints on these web pages as it becomes available.

[2] (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.

[1] (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 future.


Flanking Fields

[2] (12/21/98) The final reprocessed data for all the WFPC2 Flanking Field observations are now available. This includes the positions 1-9, as well as the longer, 9 orbit, observations taken in parallel with STIS observations of the NICMOS deep field.

[1] (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.



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This page was last updated on December 23, 1998.
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