NASA Hubble Space Telescope Daily Report # 3374
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3374
PERIOD COVERED: DOYs 150-152
OBSERVATIONS SCHEDULED
ACS 9472
A Snapshot Survey for Gravitational Lenses among z >= 4.0 Quasars
Over the last few years, the Sloan Digital Sky Survey has revolutionized
the
study of high-redshift quasars by discovering over 200 objects with
redshift
greater than 4.0, more than doubling the number known in this redshift
interval.
The sample includes eight of the ten highest redshift quasars known. We
propose
a snapshot imaging survey of a well-defined sample of 250 z > 4.0 quasars
in
order to find objects which are gravitationally lensed. Lensing models
including
magnification bias predict that at least 4% of quasars in a flux-limited
sample
at z > 4 will be multiply lensed. Therefore this survey should find of
order 10
lensed quasars at high redshift; only one gravitationally lensed quasar
is
currently known at z > 4. This survey will provide by far the best sample
to
date of high-redshift gravitational lenses. The observed fraction of
lenses can
put strong constraints on cosmological models, in particular on the
cosmological
constant Lambda. In addition, magnification bias can significantly bias
estimates of the luminosity function of quasars and the evolution
thereof; this
work will constrain how important an effect this is, and thereby give us
a
better understanding of the evolution of quasars and black holes at early
epochs, as well as constrain models for black hole formation.
ACS 9468
ACS Grism Parallel Survey of Emission- line Galaxies at Redshift z pl 7
We propose an ACS grism parallel survey to search for emission-line
galaxies
toward 50 random lines of sight over the redshift interval 0 < z pl 7. We
request ACS parallel observations of duration more than one orbit at high
galactic latitude to identify ~ 300 HAlpha emission-line galaxies at
0.2 pl
z pl
0.5, ~ 720 O IILambda3727 emission-line galaxies at 0.3 pl z pl 1.68, and
pg
1000 Ly-alpha emission-line galaxies at 3 pl z pl 7 with total emission
line
flux f pg 2* 10^-17 ergs s^-1 cm^-2 over 578 arcmin^2. We will obtain
direct
images with the F814W and F606W filters and dispersed images with the
WFC/G800L
grism at each position. The direct images will serve to provide a zeroth
order
model both for wavelength calibration of the extracted 1D spectra and for
determining extraction apertures of the corresponding dispersed images.
The
primary scientific objectives are as follows: {1} We will establish a
uniform
sample of HAlpha and O II emission-line galaxies at z<1.7 in order to
obtain
accurate measurements of co-moving star formation rate density versus
redshift
over this redshift range. {2} We will study the spatial and statistical
distribution of star formation rate intensity in individual galaxies
using the
spatially resolved emission-line morphology in the grism images. And {3}
we
will
study high-redshift universe using Ly-alpha emitting galaxies identified
at z
pl 7 in the survey. The data will be available to the community
immediately as
they are obtained.
ACS 9657
ACS Internal Flat Field Stability
The flat field stability and characterisation obtained during the ground
calibration and SMOV phases will be tested and verified through a
sub-sample of
the filter set. Only internal exposures with the calibration lamps will
be
required.
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.
ACS 9400
ARE THERE YOUNG GALAXIES IN THE LOCAL UNIVERSE: THE AGE OF THE BLUE
COMPACT
DWARF GALAXY I ZW 18
The question of whether there exists young galaxies in the local universe
is
important for cosmology. Cold Dark matter models predict that low-mass
galaxies
could still be forming at the present epoch. In the hierarchical model of
galaxy
formation, large galaxies result from the merging of smaller structures.
These
primordial building-block galaxies are too faint and small to be studied
at
high
redshifts, while we stand a much better chance of understanding them if
we can
find some local examples. One of the best candidates for being a young
nearby
galaxy forming stars for the first time at the present epoch, is the blue
compact dwarf {BCD} galaxy I Zw 18 because of its extremely low heavy
element
content {2% that of the Sun}. We propose to obtain deep $V$ and $I$ ACS
images
of I Zw 18. Our goal is to detect or put limits on the red giant branch
{RGB}
stellar population in this galaxy. If RGB stars are not detected, then we
can
set an upper limit for the age of I Zw 18 to be less than 1 Gyr. If they
are
detected, I Zw 18 is not young, and the RGB tip can be used to derive its
distance and set limits on the metallicity of the pregalactic gas.
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.
ACS 9480
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.
ACS 9476
Galaxy Evolution in the Richest Clusters at z=0.8: the EDisCS Cluster
Sample
The study of distant cluster galaxies requires two key ingredients: {1}
deep
high-resolution imaging, to constrain galaxy structure; and {2} 8m-class
spectroscopy, to measure stellar content, star-formation rates, dynamics,
and
cluster membership. We will reach both conditions with the addition of
HST/ACS
imaging to our suite of VLT {36 nights} and NTT {20 nights} observations
of 10
confirmed clusters at z~0.8, drawn from the ESO Distant Cluster Survey
{EDisCS}.
The proposed HST/ACS data will complement our existing optical/IR imaging
and
spectroscopy with quantitative measures of cluster galaxy morphologies
{i.e.
sizes and shapes, bulge-disk decompositions, asymmetry parameters}, and
with
measurements of cluster masses via weak lensing. Major advantages unique
to the
EDisCS project include: {i} uniform selection of clusters; {ii} large
enough
sample sizes to characterize the substantial cluster-to-cluster variation
in
galaxy populations; {iii} large quantities of high quality data from 8m
telescopes; {iv} uniform measurements of morphologies, spectroscopic and
photometric redshifts, SEDs, star-formation/AGN activities, and internal
kinematics; {v} optical selection of clusters to complement the X-ray
selection
of almost all high-z clusters in the ACS GTO programs; {vi} forefront
numerical
simulations designed specifically to allow physical interpretation of
observed
differences between the high-z and local clusters.
ACS 9420
Intensive Coverage of the Eta Carinae Event in 2003
For a variety of reasons, HST can provide a very special and unique data
set
when Eta Car experiences its next spectroscopic event in mid-2003.
Explaining
the phenomenon is only part of the motivation. This star and its ejecta
have
unique characteristics that make them important for several branches of
astrophysics; and when a spectroscopic event occurs, it’s like varying
the
parameters in an experiment {or rather, set of experiments}. The 2003
event
will
be the last chance in the forseeable future to obtain such a data set.
Eta
Carinae has extreme parameters; it is mysterious in surprisingly basic
ways; and
HST/STIS can gather useful data on it at a terrific rate. As we explain
below,
the proposed data set will be valuable in several independent ways: It
will
help
solve a specific set of current problems, it will constitute a large and
unique
archival data base for both stellar and nebular astrophysics, and it will
be
well-suited for educational uses.
ACS/HRC 9391
High-Resolution Imaging of Pluto’s Surface
We will collect a series of observations with the ACS/HRC from which we
will
derive a two-color global map of Pluto’s surface. We will image Pluto at
F435W
and F555W, wavelengths that have been extensively studied from the ground
over
the past 50 years. The maps will provide albedos with accurate error
determinations down to 52 degrees South latitude. These observations will
provide a second epoch of HST mapping of the active surface of Pluto as
it
continues to recede from the Sun and will provide an important context
for
other
detailed studies of Pluto.
FGS1R 9408
Calibrating the Mass-Luminosity Relation at the End of the Main Sequence
We propose to use HST-FGS1R to calibrate the mass-luminosity relation
{MLR} for
stars less massive than 0.2 Msun, with special emphasis on objects near
the
stellar/brown dwarf border. Our goals are to determine M_V values to 0.05
magnitude, masses to 5 than double the number of objects with masses
determined
to be less than 0.20 Msun. This program uses the combination of
HST-FGS3/FGS1R
at optical wavelengths and ground-based infrared interferometry to
examine
nearby, subarcsecond binary systems. The high precision measurements with
HST-FGS3/FGS1R {to 1 mas in the separations} for these faint targets {V =
10–15} simply cannot be equaled by any ground based technique. As a
result of
these measurements, we are deriving high quality luminosities and masses
for the
components in the observed systems, and characterizing their spectral
energy
distributions from 0.5 to 2.2 Mum. Several of the objects included have M
< 0.1
Msun, placing them at the very end of the stellar main sequence. Three of
the
targets are brown dwarf candidates, including the current low mass record
holder, GJ 1245C, with a mass of 0.062 +/- 0.004 Msun. The payoff of this
proposal is high because all 10 of the systems selected have already been
resolved with HST- FGS3/FGS1R during Cycles 5–10 and contain most of the
reddest objects for which masses can be determined.
NICMOS/STIS CCD 9405
The Origin of Gamma-Ray Bursts
The rapid and accurate localization of gamma-ray bursts {GRBs} promised
by a
working HETE-2 during the coming year may well revolutionize our ability
to
study these enigmatic, highly luminous transients. We propose a program
of HST
and Chandra observations to capitalize on this extraordinary opportunity.
We
will perform some of the most stringent tests yet of the standard model,
in
which GRBs represent collimated relativistic outflows from collapsing
massive
stars. NICMOS imaging and STIS CCD spectroscopy will detect broad atomic
features of supernovae underlying GRB optical transients, at luminosities
more
than three times fainter than SN 1998bw. UV, optical, and X-ray
spectroscopy
will be used to study the local ISM around the GRB. Chandra spectroscopy
will
investigate whether the GRB X-ray lines are from metals freshly ripped
from the
stellar core by the GRB. HST and CTIO infra-red imaging of the GRBs and
their
hosts will be used to determine whether `dark’ bursts are the product of
unusually strong local extinction; imaging studies may for the first time
locate
the hosts of `short’ GRBs. Our early polarimetry and late-time broadband
imaging
will further test physical models of the relativistic blast wave that
produces
the bright GRB afterglow, and will provide unique insight into the
influence of
the GRB environment on the afterglow.
STIS 9049
Boron in G64-12: Higher Big Bang Lithium or Signature of the Nu-Process?
The extremely metal-poor { Fe/H ~ -3.3 } star G64-12 shows a remarkable
lithium
{Li} abundance that is about 2 times larger than those seen in other warm
metal-poor stars, from which the Big Bang Li abundance is inferred. This
star’s
enhanced Li has resulted from either 1. Galactic Li enrichment from a
lower Big
Bang value, or 2. stellar depletion from a higher Big Bang value, with
significant cosmological implications. We argue against two of the three
prominent mechanisms of Galactic Li enrichment, leaving the theoretical
Nu-process in Type II supernovae as the sole viable mechanism. This
mechanism’s
crisp signature is the concomitant production of copious amounts of boron
{B};
if the Nu-process enriched the material out which G64-12 formed with the
extra
Li observed today, then this star should also exhibit a large detectable
B
overabundance. B in G64-12 can only be observed from space, using
HST/STIS. If
this star’s STIS-based B abundance lies above the established B-Fe trend,
this
would be the first observational evidence for the Nu-process. But if its
B
abundance lies near the B-Fe trend, this would provide direct evidence
that
G64-12 is an elusive fossil of a Big Bang Li abundance about 0.3 dex
above
currently favored values, providing consistency in standard Big Bang
Nucleosynthesis between Li and D {but not 4He}. EITHER RESULT would be of
fundamental importance to Astronomy.
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 9606
CCD Dark Monitor-Part 2
Monitor the darks for the STIS CCD.
STIS 9447
Characterizing the Atmosphere of an Extrasolar Planet
HD 209458 b is the first extrasolar planet known to transit the disk of
its
parent star. Precise measurement of both the photometric transit curve
and the
radial velocity orbit has allowed for an accurate estimation of the mass,
radius, average density, and surface gravity. Numerous theoretical
investigations of the planetary atmospheres have been presented in the
literature, but no data capable of addressing these has yet been
published. We
propose to use the method of transmission spectroscopy to constrain
greatly
models of the planetary atmosphere. We will use STIS to disperse the
stellar
flux over a large number of detector pixels. The photometric signal is
produced
by summing the counts over a desired band. For each of twelve bands
spanning the
UV to the near-IR, we will obtain sufficient precision to detect
variations in
the transit depth greater than 5 X 10^-5. We have already made a
detection of
the sodium absorption signature in the planetary atmosphere. With these
new
data, we will be able to detect, if present, absorption due to Rayleigh
scattering, water bands, and/or strong alkali metal lines. These
observations
will allow us to determine the broad characteristics of the planetary
atmosphere. For example, we will be able to distinguish between models
with a
high cloud deck, and those with no clouds but reduced chemical
abundances.
STIS 9633
STIS parallel archive proposal – Nearby Galaxies – Imaging and
Spectroscopy
Using parallel opportunities with STIS which were not allocated by the
TAC, we
propose to obtain deep STIS imagery with both the Clear {50CCD} and
Long-Pass
{F28X50LP} filters in order to make color-magnitude diagrams and
luminosity
functions for nearby galaxies. For local group galaxies, we also include
G750L
slitless spectroscopy to search for e.g., Carbon stars, late M giants and
S-type
stars. This survey will be useful to study the star formation histories,
chemical evolution, and distances to these galaxies. These data will be
placed
immediately into the Hubble Data Archive.
STIS 9708
STIS Pure Parallel Imaging Program: Cycle 11
This is the default archival pure parallel program for STIS during cycle
11.
WF/PC-2 9142
The Structure and Physics of Extragalactic Jets.
The WF/PC-2 was used to perform an ongoing investigation into the physics
of
jets. It is proposed to obtain polarimetry of the jets of 3C 264 and 3C
78.
WFPC2 9710
POMS Test Proposal: WFII backup parallel archive proposal
This is a POMS test proposal designed to simulate scientific plans.
WFPC2 9709
POMS Test Proposal: WFII parallel archive proposal
This is the generic target version of the WFPC2 Archival Pure Parallel
program.
The program will be used to take parallel images of random areas of the
sky,
following the recommendations of the 2002 Parallels Working Group.
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.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTAR 9048: GS Acquisition (1,3,1) @ 151/10:15:20Z resulted in FL backup
(3,0,3) using
FGS 3 due to SSLE on primary FGS 1. FHST Map @
151/10:23:36Z showed RSS – 11.000
arcsec three axes errors. Under investigation.
HSTAR 9049: GS Acquisition (2,3,2) @ 151/12:55:17Z failed to RGA control
due to SRLE on
primary FGS 2. This acquisition used the same
star
that caused the failure in
HSTARs 9046, 9043, and 9039. Under investigation.
HSTAR 9050: GS Acquisition (2,1,2) @ 152/15:56:27Z resulted in FL backup
on FGS 2 due to SSLE
on FGS 1. Prior FHST FM updates (U1,2FM) showed
attitude errors of 26.691, 33.146,
and -2.084. Under investigation.
COMPLETED OPS REQs: NONE
OPS NOTES EXECUTED:
910-2 SI Console response to MCE Resets after FSW 4.8 is activated @
150/16:30z
1116-0 Change Limits MAMA1 Threshold Voltage @ 150/17:26z
1114-1 Change Limits MAMA2 Threshold Voltage @ 150/17:40z
1112-1 Adjust Recharge Ratio Limits for High Sun DOY 2003/136-150, @
150/20:30z
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 18 17 See Hstar
# 9049
FGS REacq 23 23
FHST Update 36 36
LOSS of LOCK
SIGNIFICANT EVENTS:
Conducted SM-4 Aft Flight Deck Command testing 150/11:20Z –
17:10Z. Testing was
mostly successful, another run will be required after further
investigation
by DMS
and HITT and script modifications are completed. Testing was delayed by
data
dropouts requiring IPNOC disabling and re-enabling CD3 and the need to
fall
back
to an earlier PSS release to assist in troubleshooting.
Preliminary testing of VEST SIMSS Box #2 scheduled 153/11:00Z – 16:00Z
with
GDOC, SOC,
HITT, and CCS using CCS "B" String with CCS Release 4.0.2.2 and PRD
O06100R1T. The
purpose of this testing is to verify the command and telemetry data
configuration
between the SOC and STOCC via the VEST SIMSS interface.
