NASA Hubble Space Telescope Daily Report # 3782
HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science
DAILY REPORT # 3782
PERIOD COVERED: DOY 24
OBSERVATIONS SCHEDULED
ACS/HRC/WFC 10367
ACS CCDs daily monitor- cycle 13 – part 1
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.
ACS/WFC 10429
Streaming Towards Shapley: The Mass of the Richest Galaxy
Concentration in the Local Universe
The 600 km/s motion of the Local Group {LG} with respect to the cosmic
microwave background {CMB} is now known to high accuracy. However, its
precise origin remains poorly understood. The contribution to the
motion from the pull of the rich Shapley supercluster at z = 0.048 is
particularly controversial. This extreme mass concentration contains
more than 20 Abell clusters within 35 Mpc of its very rich central
cluster A3558, and is recognized as both the optically richest and the
most X-ray luminous structure in the local {z < 0.1} universe. Yet,
published values for the mass of Shapley continue to differ by an
order of magnitude, and recent estimates of its pull on the LG range
from negligible {20 km/s} to highly significant {300 km/s or more}.
Here we propose to resolve this key issue by using ACS to measure
high-precision surface brightness fluctuation {SBF} distances in order
to make a direct measurement of the infall towards Shapley. We will
target three Shapley foreground clusters where the infall is expected
to be high {possibly 1000 km/s or more}, as well as the Shapley core,
in order to test the assumption that it is at rest in the CMB. Prior
to ACS, the Shapley region was unreachable for SBF, but ACS doubles
the distance range of the SBF method with HST, enabling the distances
to be measured to the required accuracy. The proposed measurements
will place a firm limit on the largest mass fluctuation in the nearby
universe and finally determine its contribution to the observed CMB
dipole.
ACS/WFC/NIC2 10189
PANS-Probing Acceleration Now with Supernovae
Type Ia supernovae {SNe Ia} provide the most direct evidence for an
accelerating Universe, a result widely attributed to dark energy.
Using HST in Cycle 11 we extended the Hubble diagram with 6 of the 7
highest-redshift SNe Ia known, all at z>1.25, providing conclusive
evidence of an earlier epoch of cosmic deceleration. The full sample
of 16 new SNe Ia match the cosmic concordance model and are
inconsistent with a simple model of evolution or dust as alternatives
to dark energy. Understanding dark energy may be the biggest current
challenge to cosmology and particle physics. To understand the nature
of dark energy, we seek to measure its two most fundamental
properties: its evolution {i.e., dw/dz}, and its recent equation of
state {i.e., w{z=0}}. SNe Ia at z>1, beyond the reach of the ground
but squarely within the reach of HST with ACS, are crucial to break
the degeneracy in the measurements of these two basic aspects of dark
energy. The SNe Ia we have discovered and measured with HST in Cycle
11, now double the precision of our knowledge of both properties. Here
we propose to quadruple the sample of SNe Ia at z>1 in the next two
cycles, complementing on-going surveys from the ground at z<1, and
again doubling the precision of dark energy constraints. Should the
current best fit model prove to be the correct one, the precision
expected from the current proposal will suffice to rule out a
cosmological constant at the 99% confidence level. Whatever the
result, these objects will provide the basis with which to extend our
empirical knowledge of this newly discovered and dominant component of
the Universe, and will remain one of the most significant legacies of
HST. In addition, our survey and follow-up data will greatly enhance
the value of the archival data within the target Treasury fields for
galaxy studies.
NIC/NIC3 10226
The NICMOS Grism Parallel Survey
We propose to continue managing the NICMOS pure parallel program.
NIC1 10143
Ultracool companions to the nearest L dwarfs
We propose to conduct the most sensitive survey to date for low mass
NICMOS 8790
NICMOS Post-SAA calibration – CR Persistence Part 1.
A new procedure proposed to alleviate the CR-persistence problem of
WFPC2 10356
WFPC2 Cycle 13 Decontaminations and Associated Observations
This proposal is for the monthly WFPC2 decons. Also included are
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary
COMPLETED OPS REQs: None
OPS NOTES EXECUTED: None
Based on our experience, we are well prepared to make optimal use of
the parallel opportunities. The improved sensitivity and efficiency of
our observations will substantially increase the number of
line-emitting galaxies detected. As our previous work has
demonstrated, the most frequently detected line is Halpha at
0.7
companions to nearby L dwarfs. We will use NICMOS to image targets
drawn from a volume-complete sample of 70 L dwarfs within 20 parsecs.
The combination of infrared imaging and proximity will allow us to
search for T dwarf companions at separations as small as 1.6 AU. This
is crucial, since no ultracool binaries are currently known with
separations exceeding 15 AU. Only 10 dwarfs in this sample have
previous HST observations primarily at optical wavelengths. With the
increased sensitivity of our survey, we will provide the most
stringent test to date of brown dwarf models which envisage formation
as ejected stellar embryos. In addition, our observations will be
capable of detecting binaries with mass ratios as low as 0.3, and will
therefore also test the apparent preference for equal-mass ultracool
binaries. Finally, our observations offer the best prospect to date of
detecting companions significantly cooler than the coolest t dwarf
currently known.
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.
instrument monitors tied to decons: photometric stability check, focus
monitor, pre- and post-decon internals {bias, intflats, kspots, &
darks}, UV throughput check, VISFLAT sweep, and internal UV flat
check.
reports of potential non-nominal performance that will be
investigated.) None
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS Gsacq 5 5
FGS Reacq 10 10
FHST Update 7 7
LOSS of LOCK
SIGNIFICANT EVENTS: None
