Daily # 4139

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4139

PERIOD COVERED: UT June 20, 2006 (DOY 171)

OBSERVATIONS SCHEDULED

NIC3 10632

Searching for galaxies at z6.5 in the Hubble Ultra Deep Field

We propose to obtain deep ACS {F606W, F775W, F850LP} imaging in the
area of the original Hubble Ultra Deep Field NICMOS parallel fields
and - through simultaneous parallel observations - deep NICMOS {F110W,
F160W} imaging of the ACS UDF area. Matching the extreme imaging depth
in the optical and near-IR bands will result in seven fields with
sufficiently sensitive multiband data to detect the expected typical
galaxies at z=7 and 8. Presently no such a field exist. Our combined
optical and near-IR ultradeep fields will be in three areas separated
by about 20 comoving Mpc at z=7. This will allow us to give a first
assessment of the degree of cosmic variance. If reionization is a
process extending over a large redshift interval and the luminosity
function doesn't evolve strongly beyond z=6, these data will allow us
to identify of the order of a dozen galaxies at 6.5z8.5 - using the
Lyman break technique - and to place a first constrain on the
luminosity function at z6.5. Conversely, finding fewer objects would
be an indication that the bulk of reionization is done by galaxies at
z=6. By spending 204 orbits of prime HST time we will capitalize on
the investment of 544 prime orbits already made on the Hubble Ultra
Deep Field {UDF}. We have verified that the program as proposed is
schedulable and that it will remain so even if forced to execute in
the 2-gyro mode. The data will be non-proprietary and the reduced
images will be made public within 2 months from the completion of the
observations.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration - CR Persistence Part 4

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. The keyword 'USEAFTER=date/time' will also be added to
the header of each POST-SAA DARK frame. The keyword must be populated
with the time, in addition to the date, because HST crosses the SAA ~8
times per day so each POST-SAA DARK will need to have the appropriate
time specified, for users to identify the ones they need. Both the raw
and processed images will be archived as POST-SAA DARKSs. Generally we
expect that all NICMOS science/calibration observations started within
50 minutes of leaving an SAA will need such maps to remove the CR
persistence from the science images. Each observation will need its
own CRMAP, as different SAA passages leave different imprints on the
NICMOS detectors.

NIC2 10755

Photometric Standard Clusters for Cross-Observatory Calibration

The goal of this program is to obtain NICMOS photometry of selected
solar analog stars in selected Galactic clusters that will be used as
on-orbit photometric standard star fields for JWST-NIRCAM. The
availability of such fields at JWST launch will facilitate rapid
photometric calibration of NIRCAM. The NIRCAM team plans to observe
the chosen clusters with Spitzer- IRAC.


FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)

HSTARS: (None)

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 13 13
FGS REacq 02 02
OBAD with Maneuver 30 30

SIGNIFICANT EVENTS:

Flash Report: Status Briefing - ACS Suspend Status Update

A follow-up briefing was held at 1 pm on June 20, 2006 to review the
status of the analysis on the ACS suspend event.

Discussion/Agreements:

The preliminary data analysis of the event was presented as well as a
review of the data collection process and the A/D FIFO Error handling.
The forward plan for the STScI regarding the present SMS and near-term
SMSs was discussed. It was agreed to intercept the science timeline
with an SMS without ACS effective 8am EDT Thursday and to develop next
week's SMS without ACS activities. The STScI will be ready to provide
an intercept SMS with ACS observations when needed. The options for
on-orbit tests to troubleshoot side 1 were also discussed.

It was agreed to reconvene on Thursday at 1pm to review the hardware
assessment and the options for on-orbit activities.