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Hubble Space Telescope
NICMOS STScI Analysis Newsletter 20

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              |  N   N IIIII CCCCC M       M OOOOOO   SSS  |
  STScI       |  NN  N   I   CC    MM     MM OO  OO  SS    | STAN - NICMOS
  Analysis    |  N N N   I   CC    M M   M M OO  OO   SS   | Number 20 
  News        |  N  NN   I   CC    M  M M  M OO  OO    SS  | October 1999
              |  N   N IIIII CCCCC M   M   M OOOOOO  SSS   |
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CONTENTS:


        - NICMOS NEWS
          + NICMOS Software Task Updates in STSDAS Version 2.1

        - RECENT PREPRINTS

        - APPENDIX:  NICMOS CONTACTS

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				NICMOS NEWS
				-----------

NICMOS Software Task Updates in STSDAS Version 2.1
--------------------------------------------------
	by Howard Bushouse


STSDAS version 2.1 was publically released on October 9, 1999. This
release contains changes to several NICMOS-related software tasks.

The calnica calibration task has been updated to version 3.3. This version
contains the following changes:

  1) A new calibration step, BARSCORR, has been added, which is designed
  to search for and flag pixels in individual readouts of a Multiaccum
  exposure that are affected by the electronic "bars" image anomaly. The
  step can be controlled by adding the new calibration switch keyword
  "BARSCORR" to the primary headers of raw data files, but it will be executed
  automatically for Multiaccum images if this switch is not present in the
  image headers.

  2) The capability has been added to reject a user-selected number of
  initial readouts from a Multiaccum image in the CRIDCALC image combination
  and cosmic-ray rejection step. This is often useful for removing the
  effects of imcomplete shading removal by the DARKCORR calibration step.
  The number of samples to reject is set via the new task parameter "samprej".

  3) All operations throughout calnica that convert data from units of
  counts to countrates (and vice versa) have been modified to use the exposure
  time per pixel data in the TIME image extensions, rather than the value of
  the SAMPTIME header keyword.

  4) The NOISCALC step has been enhanced to estimate and account for
  "shading" signal when estimating noise in the detected signal in an image.
  In order to accomplish this, this step must now use data from the DARKFILE
  reference file, in addition to the NOISFILE reference file. This leads to
  much improved noise estimates, especially for camera 2 (which has the 
  strongest shading signal). The improved noise estimates in turn allow for
  more robust cosmic-ray rejection in the CRIDCALC step.

  5) The NLINCORR step has been upgraded to accomodate the use of
  2nd-order correction schemes, in addition to the existing 1st-order scheme.

The calnicb calibration task has been upgraded to version 2.3.1 and contains
minor bug fixes and internal modifications only.

The pstack task in the nicmos package has been upgraded to allow reading and
plotting data from any of the five types of image extensions (SCI, ERR, DQ,
SAMP, TIME), plotting in either units of counts or countrates, and the
option of saving the data to an output text file.

Finally, the NICMOS data reduction and analysis tasks that were released
earlier this year in the "nicproto" add-on package to IRAF (see NICMOS 
STAN-018, July 199) are now available in the standard nicmos package of
STSDAS v2.1. If you had previously installed the nicproto package, you
should remove it after upgrading to STSDAS v2.1 in order to avoid the
chance of conflicts.


=============================================================================

                         RECENT PREPRINTS
                         ----------------

We draw your attention to these papers, based on NICMOS data, that
will appear in the next few months.  This list includes all preprints 
received by the STScI Library not yet published in the journals.
Please remember to include our Library in your preprint distribution list.

REIPURTH, B.; YU, K.C.; RODRIGUEZ, L.F.; HEATHCOTE, S.;
BALLY, J.  "Multiplicity of the HH 111 Jet Source: Hubble
Space Telescope NICMOS Images and VLA Maps"  A&A accepted

DICKINSON, M.; HANLEY, C.; ELSTON, R.; EISENHARDT, P.R.;
STANFORD, S.A.; ADELBERGER, K.L.; SHAPLEY, A.; STEIDEL,
C.C.; PAPOVICH, C.; SZALAY, A.S.; BERSHADY, M.A.;
CONSELICE, C.J.; FERGUSON, H.C.; FRUCHTER, A.S.  "The
Unusual Infrared Object HDF-N J123656.3+621322"  ApJ
accepted

SCHULTE-LADBECK, R.E.; HOPP, U.; GREGGIO, L.; CRONE, M.M.
"A Near-Infrared Stellar Census of the Blue Compact Dwarf
Galaxy VII Zw 403"  AJ accepted astro-ph/9909216


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                     APPENDIX: NICMOS Contacts
                     -------------------------

Any questions about the scheduling of your observations should be
addressed to your Program Coordinator. Post-Observation questions can
be addressed to your Contact Scientist. If you do not know who these
persons are, you can find the information on the WWW at
http://www.stsci.edu/public/propinfo.html.

Analysis, STSDAS or any other HST-related questions can also be
addressed to help@stsci.edu.
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