NASA Hubble Space Telescope Daily Report # 3407
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3407
PERIOD COVERED: DOY 198
OBSERVATIONS SCHEDULED
NICMOS 8791
NICMOS Post-SAA calibration – CR Persistence Part 2
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.
ACS 9401
The ACS Virgo Cluster Survey
We propose the most comprehensive imaging survey to date of low-redshift,
early-type galaxies. Our goal is to exploit the exceptional imaging
capabilities
of the ACS by acquiring deep images — in the SDSS g^ and z^ bandpasses
— for
163 E, S0, dE, dE, N and dS0 galaxies in Virgo, the nearest rich cluster.
This
extraordinary dataset would likely constitute one of the principal legacies
of
HST, and would have widespread applications for many diverse areas of
astrophysics. Our immediate scientific objectives are threefold: {1} measure
metallicities, ages and radii for the many thousands of globular clusters
{GCs}
in these galaxies, and use this information to derive the protogalactic mass
spectrum of each galaxy; {2} measure the central luminosity and color
profile of
each galaxy, and use this information to carry out a completely independent
test
of the merging hierarchy inferred from the GCs, with the aid of N-body codes
that simulate the merger of galaxies containing massive black holes; and {3}
calibrate the z^ -band SBF method, measure Virgo’s 3-D structure, and carry
out
the definitive study of the GC luminosity function’s precision as a standard
candle. Our proposed Virgo Cluster Survey will yield a database of
unprecedented
depth, precision and uniformity, and will enable us to study the record of
galaxy and cluster formation in a level of detail which will never be
possible
with more distant systems.
ACS 9482
ACS Pure Parallel Lyman-Alpha Emission Survey {APPLES}
Ly-alpha line emission is an efficient tool for identifying young galaxies
at
high redshift, because it is strong in galaxies with young stars and little
or
no dust — properties expected in galaxies undergoing their first burst of
star- formation. Slitless spectroscopy with the ACS Wide-Field Camera and
G800L
grism allows an unmatched search efficiency for such objects over the
uninterrupted range 4 <~ z <~ 7. We propose the ACS Pure Parallel Ly-alpha
Emission Survey {“APPLES”}, to exploit this unique HST capability and so
obtain the largest and most uniform sample of high redshift Ly-alpha
emitters
yet. Parallel observations will allow this survey to be conducted with
minimal
impact on HST resources, and we will place reduced images and extracted
spectra
in the public domain within three months of observation. We aim to find ~
1000
Ly-alpha emitters, 5 times the biggest current sample of Ly-alpha emitters.
This
unprecedented sample will provide robust statistics on the populations and
evolution of Ly-alpha emitters between redshifts 4–7; a robust measurement
of
the reionization redshift completely independent of the Gunn-Peterson
trough;
spatial clustering information for Ly-alpha emitters which would let us
probe
their bias function and hence halo mass as a function of redshift; many
galaxies
at redshift exceeding 6; and lower redshift serendipitous discoveries.
WFPC2 9595
WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt3/3
This dark calibration program obtains 3 dark frames every day to provide
data
for monitoring and characterizing the evolution of hot pixels.
STIS 9606
CCD Dark Monitor-Part 2
Monitor the darks for the STIS CCD.
STIS 9608
CCD Bias Monitor – Part 2
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, to build up high-S/N superbiases and track the evolution of hot
columns.
STIS 9631
Faint Standard Extension {FASTEX}
Fainter standard stars are needed for the flux calibration of COS, for the
prism
modes on ACS, and for astronomical community, in general. The bright object
safety limit for COS is 1.25 ct/s per pixel, while the total countrate
limit per
FUV detector segment is 20000/s. In addition, the GALEX project {see
Appendix}
requires more secondary standards in the flux range of the two fainter
original
FASTEX stars. Customarily, one NASA project provides observing time in
support
of other NASA projects. The existing observations of the two fainter FASTEX
standards, WD0947+857 and WD1657+343, have the most CTE losses in the G430L
data
and are still a bit marginal on S/N. Since the stellar models are normalized
to
V, good spectrophotometry to 5500A is important. All five targets will be
observed at the new G430L aperture to minimize CTE loss and at the original
aperture to constrain CTE models. Combined with additional planned cal data
for
stars of intermediate flux, the CTE model for spectra can be tuned to cover
the
full range of signal levels.
ACS 9655
ACS Post-SMOV UV Contamination Monitor
A standard star field {NGC6681} is observed about once a month through all
the
ACS broad band UV filters. NGC6681 hosts several UV spectro – photometric
standard stars for which accurate spectra have been {and will continue to
be}
measured with STIS. The target cannot be observed for three months from mid
November through to mid February, so the standard star GRW+70 will be
observed
twice in its stead. This programme continues the UV sensitivity monitoring
campaign {ACS SMOV proposal 9010} of the HRC and SBC after the end of the
SMOV
period. An SBC dark current measurement is taken as the last exposure of
each
SBC sequence.
ACS 9674
CCD Daily Monitor
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.
STIS 9786
The Next Generation Spectral Library
We propose to continue the Cycle 10 snapshot program to produce a Next
Generation Spectral Library of 600 stars for use in modeling the integrated
light of galaxies and clusters. This program is using the low dispersion UV
and
optical gratings of STIS. The library will be roughly equally divided among
four
metallicities, very low {[Fe/H] lt -1.5}, low {[Fe/H] -1.5 to -0.5},
near-solar
{[Fe/H] -0.3 to 0.1}, and super-solar {[Fe/H] gt 0.2}, well-sampling the
entire
HR-diagram in each bin. Such a library will surpass all extant compilations
and
have lasting archival value, well into the Next Generation Space Telescope
era.
Because of the universal utility and community-broad nature of this venture,
we
waive the entire proprietary period.
ACS/WFC 9789
The Distance to the Pleiades
Despite its fundamental importance to stellar astrophysics, the distance to
the
Pleiades open cluster remains in great dispute. Main-sequence fitting
results in
a distance of 132.3 +/- 1.9 pc, while the Hipparcos average parallax for
Pleaides member stars gives a distance of 116.4 +/- 2.9 pc. If the Hipparcos
distance is to be believed, our current understanding of stellar
astrophysics is
dramatically incomplete. On the other hand, it has been proposed that the
Hipparcos parallax measurement to the Pleiades suffers systematic
uncertainties
which result in the discrepancy with the main-sequence fitting technique.
The
question will remain open until an independent distance measurement to the
Pleiades cluster is performed. We will use ACS imaging to determine the
parallax
to the Pleiades to an accuracy of about 1.5%. This will resolve the current
controversy over the distance to the cluster once and for all.
ACS/HRC/WFC 9815
The Bottom of the Main Sequence in the Old, Metal-Rich Cluster, NGC 6791
We propose a photometric study of the lowest part of the main sequence of
NGC
6791, an old, rich open cluster whose metallicity is considerably higher
than
solar. The cluster is rich enough that a single ACS/WFC field will have
ample
stars for the study. For the faintest stars, proper-motion separation of
cluster
from field is essential; hence we include Cycle 14 observations. These
should
give us a color-magnitude diagram and luminosity function that reach into
the
region of the hydrogen-burning limit, thus extending the study of the latter
into a new domain of metallicity. Observational data of this type will allow
theoreticians to check many aspects of their theories of stellar structure.
We
also expect to see the white dwarf sequence of the cluster. Our team has
experience with studies of this type, and has provided the
geometric-distortion
calibration of ACS.
ACS 9984
Cosmic Shear With ACS Pure Parallels
Small distortions in the shapes of background galaxies by foreground mass
provide a powerful method of directly measuring the amount and distribution
of
dark matter. Several groups have recently detected this weak lensing by
large-scale structure, also called cosmic shear. The high resolution and
sensitivity of HST/ACS provide a unique opportunity to measure cosmic shear
accurately on small scales. Using 260 parallel orbits in Sloan textiti
{F775W}
we will measure for the first time: beginlistosetlength sep0cm
setlengthemsep0cm
setlength opsep0cm em the cosmic shear variance on scales <0.7 arcmin, em
the
skewness of the shear distribution, and em the magnification effect.
endlist Our
measurements will determine the amplitude of the mass power spectrum
sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20, and the mass density
Omega_m with s/n=4. They will be done at small angular scales where
non-linear
effects dominate the power spectrum, providing a test of the gravitational
instability paradigm for structure formation. Measurements on these scales
are
not possible from the ground, because of the systematic effects induced by
PSF
smearing from seeing. Having many independent lines of sight reduces the
uncertainty due to cosmic variance, making parallel observations ideal.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.) None
COMPLETED OPS REQs:
17002-0 Raise Battery 5 VTFE by ? K1 @198/1746z
17003-0 Restore TMDIAGs to Monitor OCA post @198/1748z
OPS NOTES EXECUTED:
1136-1 SSR Dumping Procedure Operational @198/2320
1029-0 NICMOS TPG Resets @ 198/2357z
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 8 8
FGS REacq 7 7
FHST Update 18 18
LOSS of LOCK
SIGNIFICANT EVENTS:
Battery 5 VTFE was set at K1L5 equivalent, causing Battery 5 to reach
cut-off at a
lower Voltage than the other batteries. Battery 5 was operating at
temperatures
at or below -2 ?C. Battery 5 VTFE curve can be incrementally raised to
increase
battery capacity without significantly increasing power dissipation and
battery
temperature. Successfully increased Battery 5 VTFE curve by one half of a
CCC K1
charge level (about 280 milliVolts) and increased the VTFE charge-on Voltage
Threshold Offset value from 14 counts to 16 counts (OR 17002 with attached
Battery
5 VTFE Curve and Charge-On Threshold Procedure) @ 198/17:47Z). EPS and FSW
verified
nominal TRSWCC/VTFE and OCA operations for the initial orbit following the
uplink.
EPS continues to closely monitor the power system to assess the effects of
these changes.
Successfully completed check-out of CCS Release 4.0.3 SMAR/SSAR DG2
Operations Data
Messages (ODMs) fix (CR 8131) @ 198/19:07Z. Scheduled five TDRSS events on
TDRS 171, 275, or TDE. Events were exclusively for ODM display
verification;
no HST telemetry was acquired. During regression testing, observed SMAF ODM
data indicated Active for 1 minute past the termination time of the service.
Service finally went Inactive once the SMAR service was terminated.
Successfully executed new SSR dumping procedures. Since the dump did not
result in any requests
for a re-dumps from PACOR-A, the re-dumping portion of the new ROP was not
executed. DMS is
remotely monitoring the execution of subsequent dumping procedures as the
SSR Dump Log is
populated with entries, as well as any necessary subsequent
re-dumping. Executed
Ops Note 1136-1: SSR Dumping Procedure Operational @ 198/23:20Z to verify
SSR Log
information was properly transferred to backup CCS Ops strings.
