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NICMOS STScI Analysis Newsletter 16

NICMOS STScI Analysis Newsletter 16

January 1999


        - NICMOS NEWS
          + New NICMOS Information on the WWW
          + NICMOS End of Cryogen
	  + Where did all the time go?





New NICMOS Information on the WWW
	by Sherie Holfeltz

As with all Space Telescope instruments, the NICMOS home page is updated 
regularly. This page can be found from the STScI home page 
( by following the "Instruments" link.

Since the last STAN, the following items have been updated:
	End of Cryogen Status
	Focus/Plate Scale

Since the last STAN, the following ISR has been published:
	NICMOS Mode-1 Coronagraphic Acquisition
	(A.B. Schultz, K. Noll, A. Storrs, D. Fraquelli, T. Ellis, and 
	G. Schneider, January 19, 1999)

NICMOS End of Cryogen
	by Alex Storrs

The dewar and its contents have been warming slowly (only a degree 
or so) through December, but on January 3rd the warmup took a 
dramatic upturn. This upturn indicates that the cryogen has been completely  
exhausted. Flatfield and focus monitoring continued until filter 
wheel commands were stopped on January 7th. By the end of the week 
the detector temperature had climbed through 78 degrees K, the limit for 
the temperature sensors. Dark monitoring continued through this period 
as well (the filter wheels were left with the BLANK in place). Results 
of the analysis of these data are available on the STScI NICMOS web 
site ( 
We are trying to characterize the behavior of the detectors at higher 
temperatures to be ready for operation with the cryocooler in cycle 9.
The recent STScI Newsletter has an article describing the NICMOS end of 

Where did all the time go?
	by Al Schultz (NICMOS), W. Kinzel (PRESTO), F. Abney (Archive)

NICMOS was installed on HST during the Second Servicing Mission in 
February 1997. Due to the thermal short, NICMOS had a reduced but 
busy life span. The first NICMOS science programs executed on 2 June, 
1997. In May, 1997, an Independent Science Review recomended that the 
existing NICMOS science allocations be increased. A special call for 
proposals was made and by December, 1997, over 1000 new GO NICMOS orbits 
were in the system. After many successful observations, including two 
NICMOS camera 3 campaigns, the last NICMOS science visit executed on 18 
December 1998. NICMOS provided HST with near-IR capability for ~18 

A total of 3,130 orbits with NICMOS as the prime instrument have 
executed, which includes GO, DD, GTO, CAL, and ENG observations.  This 
is equivalent to approximately 36 weeks of pure NICMOS HST observing, 
assuming on average 88 prime orbits are scheduled per week. In addition 
to the prime observations, 654 SNAP, 592 coordinated parallel, and 2,068 
pure parallel orbits were executed. This is approximately a quarter of 
the HST time available during this period, and about as many observations
as were originally planned for the 4-5 year lifetime of the instrument.

A total of 103,671 NICMOS observations have been added to the HST 
Archive (including GO, DD, GTO, CAL, ENG, SM2, ERO, SNAP, and parallel 
observations). Of these, approximately 64,537 (~62%) of the observations 
were from science programs. The total NICMOS volume in the Archive is 
~1.2 terabytes of data, or more than 20% of the data in the Hubble Data 
Archive. This data would fill ~200 uncompressed Sony Optical Disks 
(~6.5 gigabytes/disk). However, data is compressed and the actual 
number of optical disks needed to hold the NICMOS data is much less.  
Compression is our friend! The HST Archive currently holds approximately 
6 terabytes of data.

Data Analyst Position Available at STScI
The Space Telescope Science Institute currently has openings for
Data Analysts. Data Analysts in the Science Support Division help General
Observers and Archive Researchers analyze HST data, work with Instrument
Scientists in calibrating the HST instruments, and work with STScI staff
on grant-supported research projects. These research projects span a range
of size scales from comets and planets to the large scale structure of
the universe and a range of wavelengths from radio to X-ray astronomy.
Applicants should possess a B.S. degree (M.S. degree a plus) in astronomy
or physics, or equivalent; experience with astronomical research; familiarity
with scientific computing; expertise in data analysis; knowledge of IRAF, IDL
or other software packages for astronomical data analysis; and programming
ability. Additional mathematical, statistical, and computer skills are
desirable. Candidates should have the ability to work with a minimum of
direction, enjoy research, and possess skills to develop excellent working
relationships. Candidates should send a cover letter with current curriculum
vitae and the names of three references to:
Human Resources Manager
Space Telescope Science Institute
3700 San Martin Dr.
Baltimore, MD 21218
Women and minorities are strongly urged to apply. AAE/EOE.


                         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 
by the STScI Library not yet published in the journals.  Please remember to
include our Library in your preprint distribution list.

PULONE, L.; DE MARCHI, G.; PARESCE, F.  "The Mass Function
of M4 from Near IR and Optical HST Observations"  A&A

and Ultraluminous Infrared Galaxies: At the Limit?"  ApJ

B.A.; TERRILE, R.J.; THOMPSON, R.I.  "A Candidate
Substellar Companion to CoD -33 deg. 7795 (TWA 5)"  ApJ


                     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

Analysis, STSDAS or any other HST-related questions can also be
addressed to
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