Hubble Space Telescope Daily Report #3130 – 4 Jun 2002

HUBBLE SPACE TELESCOPE

DAILY REPORT # 3130

PERIOD COVERED: DOY 155: 0000Z (UTC) 06/03/02 – 0000Z (UTC) 06/04/02

OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

STIS 8594

H-deficient condensations in PNe — a key to discrepancies in abundance
determinations

Much of our knowledge of elemental abundances in our own and other galaxies
rests on emission line nebulae. Our recent CNO abundance determinations for Pne
using optical recombination lines {ORLs} have yielded abundances systematically
higher than the `standard’ values deduced from UV/optical collisionally excited
lines {CELs}, with discrepancies covering a wide range from 1–20. In the
extreme case of NGC 6153, multi-waveband analysis has yielded CNO and Ne
abundances from ORLs which are all about a factor of ten higher than the CEL
values. Temperature fluctuations and density inhomogeneities fail to
explain all
the available data. Instead our analysis indicates that NGC 6153 may have
experienced a recent ejection of H-deficient knots, similar to those
observed in
the `born-again’ PN Abell 30. We propose to obtain deep STIS long-slit spectra
for the well-resolved H- deficient knots of A 30 and to search for such
knots in
NGC 6153. The data will yield the spatially resolved temperature, density and
ionization structure of the knots in Abell 30, and, for the first time,
accurate
ORL C and O abundances for them. The results will lead to a much better
understanding of the physics of such knots and their effects on abundance
determinations. The observations of NGC 6153 will allow us to test if the
observed central peaking of its ORL C and O abundances is a consequence of a
central concentration of similar H-deficient knots.

NICMOS 8790

NICMOS Post-SAA calibration – CR Persistence Part 1.

A new procedure proposed to alleviate the CR-persistence problem of NICMOS.
Dark
frames will be obtained immediately upon exiting the SAA contour 23, and every
time a NICMOS exposure is scheduled within 50 minutes of coming out of the SAA.
The darks will be obtained in parallel in all three NICMOS Cameras. The
POST-SAA
darks will be non-standard reference files available to users with a USEAFTER
date/time mark.

STIS/CCD 8902

Dark Monitor-Part 2.

The Space Telescope Imaging Spectrograph (CCD) was used to monitor the darks.

STIS/CCD 8904

Bias Monitor-Part 2.

The Space Telescope Imaging Spectrograph (CCD) was used to monitor the bias in
the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at gain = 4 in order
to build up high-S/N superbiases and track the evolution of hot columns.

STIS/MA1/MA2 8920

Cycle 10 MAMA Dark Measurements.

The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to perform the
routine monitoring of the MAMA detector dark noise, and is the primary means of
checking on health of the MAMA detectors systems through frequent monitoring of
the background count rate.

WFPC2 8938

WFPC2 CYCLE 9 SUPPLEMENTAL DARKS pt3/3.

0unch
This dark calibration program obtains 3 dark frames every day to provide data
for monitoring and characterizing the evolution of hot pixels.

ACS/WFC/HRC 8947

Weekly Test.

The Advanced Camera for Surveys (WFC and HRC) was used to perform basic
tests to
monitor, the read noise, the development of hot pixels and test for any source
of noise in ACS CCD detectors. This program will be executed at least once
a day
for the entire lifetime of ACS.

ACS 9010

SMOV Contamination Plan.

This program has two main goals: {1} manage ACS operations to minimize the risk
of contamination of its optics by materials outgassed during servicing
activity,
and {2} initiate a program to monitor the UV sensitivity of HRC and SBC as
early
as possible after the service mission.

ACS/WFC/HRC 9075

Cosmological Parameters from Type Ia Supernovae at High Redshift.

The Advanced Camera for Surveys (WFC and HRC) was used to obtain a Hubble
diagram of Type Ia supernovae {SNe Ia} that will be of long lasting value as a
record of the expansion history of the universe.

NICMOS 9269

NICMOS Parallel Thermal Background

NICMOS Camera 3 pure parallel exposures in the F222M filter will be
obtained for
the entire duration of SMOV to establish the stability of the
HST+NCS+Instrument
thermal emission.

STIS/CCD 9317

Pure Parallel Imaging Program: Cycle 10.

The Space Telescope Imaging Spectrograph (CCD) was used to perform the default
archival pure parallel program for STIS during cycle 10.

WF/PC-2 9318

POMS Test Proposal: WFII Parallel Archive Proposal Continuation.

The WF/PC-2 was used to perform the generic target version of the WFPC2
Archival
Pure Parallel program. The program was used to take parallel images of random
areas of the sky, following the recommendations of the Parallels Working
Group.

ACS/HRC 9473

Masses and IMF Variations in Super Star Clusters

We are proposing to obtain high spatial resolution images of a set of super
star
clusters for which we have been granted observing time to measure velocity
dispersions via high- resolution ground-based optical echelle and K-band
spectroscopy. The images will allow us to fit the light profiles and
measure the
radii of the clusters, and when combined with the velocity dispersions, will
enable us to estimate the cluster masses. By comparing the mass-to-light ratios
with those predicted from spectral synthesis models, we will investigate
possible variations in the slope and lower mass cut-offs of the initial mass
functions in these clusters. Correlations of the variations of these parameters
with cluster environment may provide insight into the formation mechanisms for
super star clusters. By comparing the light profiles obtained in a blue and red
filter, we will also search for evidence of mass segregation in the clusters.
Since these clusters are too young to have experienced dynamical mass
segregation, differences in the light profiles of the clusters in the two
filters could be due to processes that differentiate between high and low mass
stars during the birth of the clusters and would provide further constraints on
theoretical models of cluster formation. Since these clusters are far too
compact to be resolved by any ground-based observations, the ACS/HRC on board
HST is the only instrument capable of carrying out these observations.

ACS/CAL 9558

ACS weekly Test

This program consists of basic tests to monitor, the read noise, the
development
of hot pixels and test for any source of noise in ACS CCD detectors. This
programme will be executed once a day for the entire lifetime of ACS.

ACS 9564

ACS Cycle 11: UV Earth Flats

This proposal will obtain sequences of UV flats by observing the bright Earth.
The HRC UV filters were chosen for modes which were not obtained in the lab.
Since the UV transmission is likely to vary as a function of position on the
Pol_UV filters and on the coronograph, and since this behavior is currently
unconstrained by measurement, a good estimate for the missing UV flats
cannot be
made. Although POL_UV and CORON transmissions change little at long
wavelengths,
the UV transmission may change by amounts larger than can be estimated in the
absence of actual UV transmission measurements

ACS 9568

Grism/Prism Calibration

A Planetary Nebula in the LMC and a Galactic White Dwarf are observed through
the prism of the High Resolution Channel to measure: 1} the dispersion of the
prism and its field dependence; 2} the prism throughput and its field
dependence. Therefore, these measurements will be carried out at several
positions on the chip including the centre and the corners of the HRC chip. The
same White Dwarf is observed together with a Galactic Wolf-Rayet star through
the grism of the Wide Field Channel in a number of positions complementing
those
already observed in SMOV. The purpose here is to better characterize the field
dependence of the grism dispersion in the WFC.

ACS/WFC 9575

Default {Archival} Pure Parallel Program.

FLIGHT OPERATIONS SUMMARY:

HSTARs:

8672 FOF Queue buffer overflow @ 149/02:44:30z

8673 GRG2_4GT out of limits briefly @ 155/21:54:41z

COMPLETED OPS REQs:

16781-2 Adjust Battery Pressure Test Limits @ 155/1728z

16782-1 Patch Benchmark SOC & SOC1 and SOC2 Safing limits @ 155.1734z

OPS NOTES EXECUTED: NONE

                           SCHEDULED     SUCCESSFUL    FAILURE TIMES

FGS GSacq                   7                  7

FGS REacq                   6                  6

FHST Update                15                 15

LOSS of LOCK               None

Operations Notes: None

SIGNIFICANT EVENTS:

Continuation of Servicing Mission Orbital Verification and the gradual
resumption of normal science observations and calibrations.