Notice: For the foreseeable future, the daily reports may
contain
apparent discrepancies between some proposal descriptions
and the listed
instrument usage. This is due to the conversion of
previously approved
ACS WFC or HRC observations into WFPC2, or NICMOS
observations
subsequent to the loss of ACS CCD science capability in
late January.
HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4349
PERIOD COVERED: UT April 25, 2007 (DOY 115)
OBSERVATIONS SCHEDULED
WFPC2 10798
Dark Halos and Substructure from Arcs & Einstein Rings
The surface brightness distribution of extended
gravitationally lensed
arcs and Einstein rings contains super-resolved
information about the
lensed object, and, more excitingly, about the smooth and
clumpy mass
distribution of the lens galaxies. The source and lens
information can
non-parametrically be separated, resulting in a direct
"gravitational
image" of the inner mass-distribution of
cosmologically-distant galaxies
{Koopmans 2005; Koopmans et al. 2006 [astro-ph/0601628]}.
With this goal
in mind, we propose deep HST ACS-F555W/F814W and
NICMOS-F160W WFC
imaging of 20 new gravitational-lens systems with
spatially resolved
lensed sources, of the 35 new lens systems discovered by
the Sloan Lens
ACS Survey {Bolton et al. 2005} so far, 15 of which are
being imaged in
Cycle-14. Each system has been selected from the SDSS and
confirmed in
two time- efficient HST-ACS snapshot programs {cycle
13&14}.
High-fidelity multi-color HST images are required {not
delivered by the
420s snapshots} to isolate these lensed images {properly
cleaned,
dithered and extinction-corrected} from the lens galaxy
surface
brightness distribution, and apply our "gravitational
maging" technique.
Our sample of 35 early-type lens galaxies to date is by
far the largest,
still growing, and most uniformly selected. This minimizes
selection
biases and small-number statistics, compared to smaller,
often
serendipitously discovered, samples. Moreover, using the
WFC provides
information on the field around the lens, higher S/N and a
better
understood PSF, compared with the HRC, and one retains
high spatial
resolution through drizzling. The sample of galaxy mass
distributions -
determined through this method from the arcs and Einstein
ring HST
images - will be studied to: {i} measure the smooth mass
distribution of
the lens galaxies {dark and luminous mass are separated
using the HST
images and the stellar M/L values derived from a joint
stellar-dynamical
analysis of each system}; {ii} quantify statistically and
individually
the incidence of mass-substructure {with or without
obvious luminous
counter- parts such as dwarf galaxies}. Since dark-matter
substructure
could be more prevalent at higher redshift, both results
provide a
direct test of this prediction of the CDM hierarchical
structure-formation model.
WFPC2 10809
The nature of "dry" mergers in the nearby
Universe
Recent studies have shown that "dry" mergers of
red, bulge-dominated
galaxies at low redshift play an important role in shaping
today's most
massive ellipticals. These mergers have been identified in
extremely
deep ground-based images of red sequence galaxies at z ~
0.1. The
ground-based images reach surface brightness limits of AB
~ 29, but lack
the resolution to study the morphologies of the galaxies
inside the
effective radius. Here we propose to obtain ACS images of
a
representative sample of 40 of these red sequence
galaxies: 15 ongoing
dry mergers, 15 remnants, and 10 undisturbed objects. We will
measure
the isophote shapes and ellipticities of the galaxies,
their dust
content, morphological fine structure {shells and
ripples}, AGN content,
and their location on the Fundamental Plane. By comparing
galaxies in
different stages of the merging process we can constrain
the amount of
gas associated with these red mergers, the effect of
active nuclei, and
track structural changes. As two galaxies can be observed
in a single
orbit 20 orbits are requested to observe the 40 galaxies.
NIC1 11061
NICMOS Imaging of Grism Spectrophotometric Standards
In this program we will take imaging observations with all
3 cameras
with a range of filters of a significant number of stars
that are part
of the spectroscopic standard star project. These stars
will form the
fainter reference star backbone for programs as JWST,
Sophia, and SNAP.
With this program we will: 1. Accurately calibrate
relative brightness
of standard stars, which can be done more accurately with
photometry
than with spectroscopy. This has been proven to be vary
valuable to
straighten out the problems in the spectroscopic data
reduction and
calibrations so far. 2. Increase the number of stars over
a large
magnitude range to provide a more accurate cross check of
our count rate
dependent non-linearity correction 3. Include stars with
radically
different {very red} spectra to investigate whether the
filter curves as
measured before flight are still valid by comparing the
throughput
estimates from these stars to those used for the standard
calibration.
4. Repeat a few standard star observations from cycle 7
and post-NCS
installation SMOV, to increase the accuracy in the change
in sensitivity
measurement with just a few observations thanks to the
long baseline.
NIC1/NIC2/NIC3 8794
NICMOS Post-SAA calibration - CR Persistence Part 5
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.
NIC3 10792
Quasars at Redshift z=6 and Early Star Formation History
We propose to observe four high-redshift quasars {z=6} in
the NIR in
order to estimate relative Fe/Mg abundances and the
central black hole
mass. The results of this study will critically constrain
models of
joint quasar and galaxy formation, early star formation,
and the growth
of supermassive black holes. Different time scales and
yields for
alpha-elements {like O or Mg} and for iron result into an
iron
enrichment delay of ~0.3 to 0.6 Gyr. Hence, despite the
well-known
complexity of the FeII emission line spectrum, the ratio
iron/alpha -
element is a potentially useful cosmological clock. The
central black
hole mass will be estimated based on a recently revised
back hole mass -
luminosity relationship. The time delay of the iron
enrichment and the
time required to form a supermassive black hole {logM>8
Msol, tau
~0.5Gyr} as evidenced by quasar activity will be used to
date the
beginning of the first intense star formation, marking the
formation of
the first massive galaxies that host luminous quasars, and
to constrain
the epoch when supermassive black holes start to grow by
accretion.
S/C 4974
TRTTEST
The Transcient Response Test is for the periodic
performance monitoring
of the FGS 2R servo A mechanism.
WFPC2 11083
The Structure, Formation and Evolution of Galactic Cores
and Nuclei
A surprising result has emerged from the ACS Virgo Cluster
Survey
{ACSVCS}, a program to obtain ACS/WFC gz imaging for a
large, unbiased
sample of 100 early-type galaxies in the Virgo Cluster. On
subarcsecond
scales {i.e., <0.1"-1"}, the HST brightness
profiles vary systematically
from the brightest giants {which have nearly constant
surface brightness
cores} to the faintest dwarfs {which have compact stellar
nuclei}.
Remarkably, the fraction of galaxy mass contributed by the
nuclei in the
faint galaxies is identical to that contributed by
supermassive black
holes in the bright galaxies {0.2%}. These findings
strongly suggest
that a single mechanism is responsible for both types of
Central Massive
Object: most likely internally or externally modulated gas
inflows that
feed central black holes or lead to the formation of
"nuclear star
clusters". Understanding the history of gas
accretion, star formation
and chemical enrichment on subarcsecond scales has thus
emerged as the
single most pressing question in the study of nearby
galactic nuclei,
either active or quiescent. We propose an ambitious HST
program {199
orbits} that constitutes the next, obvious step forward:
high-resolution, ultraviolet {WFPC2/F255W} and infrared {NIC1/F160W}
imaging for the complete ACSVCS sample. By capitalizing on
HST's unique
ability to provide high-resolution images with a sharp and
stable PSF at
UV and IR wavelengths, we will leverage the existing
optical HST data to
obtain the most complete picture currently possible for
the history of
star formation and chemical enrichment on these small
scales. Equally
important, this program will lead to a significant
improvement in the
measured structural parameters and density distributions
for the stellar
nuclei and the underlying galaxies, and provide a
sensitive measure of
"frosting" by young stars in the galaxy cores.
By virtue of its superb
image quality and stable PSF, NICMOS is the sole
instrument capable of
the IR observations proposed here. In the case of the
WFPC2
observations, high-resolution UV imaging {< 0.1"}
is a capability unique
to HST, yet one that could be lost at any any time.
WFPC2 11020
Cycle 15 Focus Monitor
The focus of HST is measured primarily with ACS/HRC over
full CVZ orbits
to obtain accurate mean focus values via a well sampled
breathing curve.
Coma and astigmatism are also determined from the same
data in order to
further understand orbital effects on image quality and
optical
alignments. To monitor the stability of ACS to WFPC2
relative focii,
we've carried over from previous focus monitor programs
parallel
observations taken with the two cameras at suitable
orientations of
previously observed targets, and interspersed them with
the HRC CVZ
visits.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
10788 - GSAcq (1,3,1) failed to RGA Hold (Gyro Control)
At
AOS (116/01:09:46) GSAcq (1,3,1) scheduled from 116/00:55:12-01:02:31
had failed to RGA Hold (Gyro Control) due to QF1STOPF and QSTOP flag on
FGS 1.
OBAD #1 data is unavailable until the next scheduled engineering data dump.
OBAD #2: RSS 13.95
OBAD MAP: RSS 4135.71
COMPLETED OPS REQUEST:
18043-0 - TRT Test#14
18046-0 - MSS/CSS Gyro1 KF Initialization Convergence
Testing for SMS 113 Test 15
18046-0 - MSS/CSS Gyro1 KF Initialization Convergence
Testing for SMS 113 Test 14
18052-0 - PCS KF OOT Support
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS GSacq
08
07
FGS REacq
05
05
OBAD with Maneuver
30
30
SIGNIFICANT EVENTS:
Evaluation of Universal Kalman Filter performance
continued. Multiple
text segments were executed. Details follow.
The Kalman Filter (KF) was halted at 115/14:47 (OR 18046-0)
during orbit
day and during an M2G guiding interval. The filter was
restarted at
115/14:59 during orbit day, during a vehicle maneuver and
during a fast
changing B-field. The filter was activated with the MSS,
CSS and Gyro1
sensor inputs enabled. All UKF parameters showed nominal
operation. The
test was an MSS/CSS/Gyro1 Initialization Test Case with
the vehicle in
maneuver and during a fast changing B-field (MC_G1_IVF,
Test #15). The
MSS/CSS default KF configuration was restored at
115/16:45.
The Kalman Filter (KF) was halted at 115/23:50 (OR
18046-0) during orbit
day and during an T2G guiding interval. The filter was
restarted at
115/23:33 during orbit night with no vehicle maneuver and
during a slow
changing B-field. The filter was activated with the MSS,
CSS and Gyro1
sensor inputs enabled, however since the vehicle was in
orbit night no
CSS inputs were available. All UKF parameters showed
nominal operation.
The test was an MSS/Gyro1 Initialization Test Case with
the vehicle
inertially fixed and during a slow changing B-field
(M_G1_INS, Test
#14). The MSS/CSS default KF configuration was restored at
115/23:51.
The test above completes KF convergence testing for the
week of the 113
SMS.
Flash Report: TRTT
The FGS-2R TRTT was successfully completed this morning at
115/14:40z
using Ops Request 18043. Both iterations of the test
completed
nominally. OTA SEs will analyze the resulting data to
continue trending
FGS-2R.