Daily #3965

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3965

PERIOD COVERED: UT October 12, 2005 (DOY 285)

OBSERVATIONS SCHEDULED

ACS/HRC/WFC 10729

ACS CCDs daily monitor

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This programme will be
for the entire lifetime of ACS. Changes from cycle 13:- The default
gain for WFC is 2 e-/DN. As before bias frames will be collected for
both gain 1 and gain 2. Dark frames are acquired using the default
gain {2}. This program cover the period Oct, 2 2005- May, 29-2006. The
second half of the program has a different proposal number: 10758.

ACS/WFC 10526

Dynamics of the Polarization Structure of the Crab Nebula

The Crab Nebula is not a free expansion SNR. Rather, it is a pulsar
wind nebula expanding from the inside out into a larger remnant of
freely expanding ejecta. At the heart of this object is the Crab
Pulsar and the region where the pulsar's highly nonisotropic wind
interacts with the larger synchtron nebula. HST and Chandra monitoring
has shown this to be one of the most intricately structured and highly
dynamical objects ever observed. In Cycle 12 we demonstrated our
ability to use the polarization capabilities of the ACS to isolate
physically discrete features within the Crab Synchrotron Nebula and
accurately measure their polarization characteristics. These data
provide a unique look at the physical structure in the heart of the
Crab, adding a new dimension to past observations. Polarization
provides extensive information about field geometries, the degree of
disorder in the field, and particle pitch angle distributions. But one
image of the Crab is like a single image of waves at the beach. It
necessarily misses the point. In the Crab, the name of the game is
"dynamics". In this proposal we request time to monitor changes in the
polarization structure of the Crab. This program will allow us to
follow the changing polarization of features including
relativistically moving wisps in the Crab Nebula. This is the only
place in the sky where a dynamic relativistic plasma can be observed
in sufficient detail to make such measurements possible, and the
HST/ACS is the only instrument that we are likely to see in our
careers capable of making the measurement. These observations will be
an important addition to the already rich observational legacy of HST
for what is arguably the most important single object in astrophysics.

ACS/WFC 10569

A Last Look at the First Gravitational Lens

Strong gravitational lensing provides our best probe of the behavior
of dark matter in galaxy halos and their substructure. We undertake
ACS imaging to gain new strong and weak lensing data for the
first-discovered lens system Q0957+561. We will make a weak lensing
image spanning 6' to map the potential of the cluster around the lens
galaxy, and simultaneously obtain a deep image of more than 10
multiply-imaged features in the strong lensing region. This will
complete HST's legacy dataset for Q0957+561: a deep multicolor image
of a rich multiple-image system, an extremely high-quality weak
lensing map, and an existing deep NICMOS image of the Einstein ring.
We will combine these three kinds of data into a single lens model--a
first--to produce a sophisticated dark matter map that will provide a
uniquely detailed view of the relation between visible and dark matter
on galaxy scales, and the best available constraints on dark
substructure. In addition, the best available $H_0$ measurement from
lensing will potentially allow us to leverage the WMAP data into a
more precise measurement of dark energy properties as well.
Astrophysics with strong lensing depends crucially on HST's unique
capability for precise, well-resolved observations of
low-surface-brightness structures next to bright objects, so it is a
high priority to address outstanding questions before the demise of
HST.

ACS/WFC 10626

A Snapshot Survey of Brightest Cluster Galaxies and Strong Lensing to
z = 0.9

We propose an ACS/WFC snapshot survey of the cores of 150 rich galaxy
clusters at 0.3 z 0.9 from the Red Sequence Cluster Survey {RCS}.
An examination of the galaxian light in the brightest cluster
galaxies, coupled with a statistical analysis of the strong-lensing
properties of the sample, will allow us to contrain the evolution of
both the baryonic and dark mass in cluster cores, over an
unprecedented redshift range and sample size. In detail, we will use
the high- resolution ACS images to measure the metric {10 kpc/h}
luminosity and morphological disturbances around the brightest
clusters galaxies, in order to calibrate their accretion history in
comparison to recent detailed simulations of structure formation in
cluster cores. These images will also yield a well-defined sample of
arcs formed by strong lensing by these clusters; the frequency and
detailed distribution {size, multiplicity, redshifts} of these strong
lens systems sets strong constraints on the total mass content {and
its structure} in the centers of the clusters. These data will also be
invaluable in the study of the morphological evolution and properties
of cluster galaxies over a significant redshift range. These analyses
will be supported by extensive ongoing optical and near-infrared
imaging, and optical spectroscopy at Magellan, VLT and Gemini
telescopes, as well as host of smaller facilities.

ACS/WFC/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.

WFPC2 10751

WFPC2 CYCLE 14 Intflat Linearity Check and Filter Rotation Anomaly
Monitor

Intflat observations will be taken to provide a linearity check: the
linearity test consists of a series of intflats in F555W, in each gain
and each shutter. A combination of intflats, visflats, and earthflats
will be used to check the repeatability of filter wheel motions.
{Intflat sequences tied to decons, visits 1-18 in prop 10363, have
been moved to the cycle 14 decon proposal 10744 for easier
scheduling.} Note: long-exposure WFPC2 intflats must be scheduled
during ACS anneals to prevent stray light from the WFPC2 lamps from
contaminating long ACS external exposures.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

9975 - GSACQ(2,1,2) fails to acquire fine lock @ 285/11:09Z
GSACQ(2,1,2) at 285/11:01:26 failed to acquire lock. During the
acquisition attempt, QDVTHAB2 (FGS 2 Position Command A) broke limit
at 11:02:02, reaching a value of 6.22597, limit is 3.1415. Map at
11:08:45 showed errors of V1= -1.11, V2= -14.38, V3= -0.41 RSS = 14.42

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS Gsacq 06 05 See
Hstar # 9975
FGS Reacq 05 05
OBAD with Maneuver 22 22

SIGNIFICANT EVENTS: (None)