Daily 3532

HUBBLE SPACE TELESCOPE

DAILY REPORT # 3532

PERIOD COVERED: DOY 15

OBSERVATIONS SCHEDULED

ACS 9440

The Composition of Io's Pele Plume

We propose to determine the composition of Io's largest volcanic
plume, Pele, with unprecedented accuracy. This will give us new
constraints on the temperatures, pressures, and magma composition of
this volcano, and thus an improved window into Io's interior. We will
use the proven Jupiter transit spectroscopy technique, which resulted
in the discovery of S_2 gas in the Pele plume, but will use exposures
that are 4 times longer than in the discovery observations. This will
allow us to accurately measure plume SO_2 abundances, seen only with
low S/N in the discovery observations, and possibly SO, in addition to
S_2, and gives the chance to discover other, currently unknown, plume
components. We will also use ACS to obtain UV and visible images of
the Pele plume in reflected light prior to Jupiter transit, to
constrain the dust abundance and particle size in the plume. This will
allow refined estimates of plume dust/gas ratios and resurfacing
rates. We will repeat the observations four times to build up S/N to
even higher levels, and to look for time variability in both dust and
gas abundance and chemistry.

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.

ACS/CCD/WFC 9978

The Ultra Deep Field with ACS

The ACS Ultra Deep Field {UDF} is a survey carried out by using
Director's Discretionary time. The main science driver are galaxy
evolution and cosmology. The primary instrument is the Advanced Camera
for Surveys but WFPC2 and NICMOS will also be used in parallel. The
data will be made public. The UDF consists of a single ultra-deep
field {410 orbits in total} within the CDF-S GOODS area. The survey
will use four filters: F435W {55 orbits}, F606W {55 orbits}, F775W
{150 orbits}, and F850LP {150 orbits}. The F435W {B} and F606W {V}
exposures will be one magnitude deeper than the equivalent HDF
filters. The F775W {I} exposure will be 1.5 magnitude deeper than the
equivalent HDF exposure. The depth in F775W and F850LP is optimized
for searching very red objects - like z=6 galaxies - at the detection
limit of the F850LP image. The pointing will be RA{J2000}=3 32 40.0
and Decl.{J2000}=-27 48 00. These coordinates may change slightly due
to guide star availability and implementation issues. We will attempt
to include in the field both a spectroscopically confirmed z=5.8
galaxy and a spectroscopically confirmed type Ia SN at z=1.3. The
pointing avoids the gaps with the lowest effective exposure on the
Chandra ACIS image of CDFS. This basic structure of the survey
represents a consensus recommendation of a Scientific Advisory
Committee to the STScI Director Steven Beckwith. A local Working Group
is looking in detail at the implementation of the survey.

ACS/HRC 10050

ACS Earth Flats

High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L-flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronographic
monitoring is required to assess the changing position of the spots.

ACS/HRC/WFC 10059

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/WFC 9722

Life in the fast lane: The dark-matter distribution in the most
massive galaxy clusters in the Universe at z0.5

We propose two-filter ACS observations of a complete sample of 12 very
X-ray luminous galaxy clusters at 0.5z0.7 as a cornerstone of a
comprehensive multi-wavelength study of the properties of the most
massive clusters in the universe. Our sample includes the famous
systems Cl0016+16 and MS0451-03; all other clusters are new
discoveries from the MACS survey. Being the counterparts of the
best-studied systems at lower and higher redshift and comprising ALL
massive clusters at 0.5z0.7 observable from Mauna Kea this sample
will become the ultimate reference for cluster studies at z0.5. HST's
unique capabilities will allow us to: 1} measure accurately the
clusters' dark matter distribution on scales from tens to more than
500/h_50 kpc from observations of strong and weak gravitational
lensing, 2} use galaxy-galaxy lensing to measure the shape, extent,
and mass content of the dark-matter halos of both cluster and field
galaxies, and 3} study the color morphology of mergers and the star
formation history of galaxies in a high-density environment. The
proposed observations are complemented by Chandra observations of all
our targets {all 12 awarded, 11 executed to date} which provide
independent constraints on the dark matter and gas distribution in the
cluster cores, as well a by extensive groundbased observations of weak
lensing on yet larger scales, galaxy dynamics, and the SZ effect.

ACS/WFC 9772

Galaxy Populations at Very Large Cluster Radii: The Outskirts of
MS1054-03 at z=0.83

We propose to use the Advanced Camera for Surveys to image four
selected fields in the outskirts of the rich, X-ray luminous cluster
MS1054-03 at z=0.83. The high-resolution and sensitivity of ACS is
required in order to study the properties of the population of
galaxies falling into the cluster for the first time. By targeting
regions of the cluster well beyond the virial radius, we will: {1}
study the transformation of infalling field spirals into cluster
early-types using, e.g., the morphology-density relation to large
radii and very low local densities; {2} determine the star-formation
histories of those field galaxies most recently accreted by the
cluster, using accurate colors, morphologies, bulge-to- disk ratios,
bulge and disk scale lengths, M/L ratios and line strengths; and {3}
measure the frequency of galaxy-galaxy mergers and interactions in the
infall region. By combining wide-field HST/ACS data with wide-field
multi-object spectroscopy from the Magellan and Keck telescopes, we
can test the predictions made by galaxy formation models, study how
field spirals become early-type cluster members, and better constrain
the formation and evolution of galaxies in both clusters and the
field.

NIC3 9846

The Origins of Sub-stellar Masses: Searching for the End of the IMF

Is there a preferred scale that defines the end of the IMF? We propose
to test this hypothesis by conducting a deep spectroscopic survey of
extremely low mass objects in the embedded young cluster associated
with NGC1333. At a distance of only 300pc, this cluster is one of the
nearest examples of a dense young cluster. We will be able to obtain
R=200 spectra and photometry for 40-60 cluster members with masses
between 5-40 Jupiter masses at an age of 1 Myr observed through
A{v}10 mag. This will enable us to estimate temperatures and
luminosities for all sources detected in the survey. We will compare
their positions in an H-R diagram to PMS evolutionary tracks in order
to estimate their ages and masses. For a solar metallicity cloud at a
temperature of 10 K, the minimum mass for fragmentation is thought to
be 10 Jupiter masses. A statistically significant sample of objects
detected below this limit would challenge the role of hierarchical
fragmentation in limiting substellar masses. The proximity of this
cluster combined with the unique sensitivity, wavelength coverage, and
multi-object spectroscopic capability of NICMOS on HST make this
experiment possible.

NIC3 9979

The Ultra Deep Field - NICMOS Parallels

This is a plan to manage the NICMOS pure parallels of the ACS Ultra
Deep Survey. We will obtain a mix of F110W and F160W images along
sight-lines within the mosaiced ACS fields of the CDF-S GOODS and GEMS
surveys, with these sight-lines enabling an examination of the space
density and morphologies of the reddest galaxies.

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.

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.

STIS/CCD 10017

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD.

STIS/CCD 10019

CCD Bias Monitor - Part 1

Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,
and 1x1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns.

STIS/CCD 10085

STIS Pure Parallel Imaging Program: Cycle 12

This is the default archival pure parallel program for STIS during
cycle 12.

STIS/CCD 9981

The Ultra Deep Field - STIS parallels

We propose to obtain slitless spectroscopy of objects in the GEMS and
GOODS area around the UDF.

WFPC2 10069

WFPC2 CYCLE 12 Supplemental Darks, Part 1/3

This dark calibration program obtains 3 dark frames every day to
provide data for monitoring and characterizing the evolution of hot
pixels.

WFPC2 10084

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 9980

The Ultra Deep Field - WFPC2 Parallels

The ACS Ultra Deep Field {UDF} is a survey carried out by using
Director's Discretionary time. The main science drivers are galaxy
evolution and cosmology. The primary instrument is the Advanced Camera
for Surveys but WFPC2, NICMOS, and STIS will also be used in pure
parallel mode. The data will be made public. The UDF consists of a
single ultra-deep field {410 orbits in total} within the CDF-S GOODS
area. We request a modification of the default pure parallel programs.
Rather than duplicate the redder bands which will be done much better
with ACS, we propose to observe in the near-ultraviolet F300W filter.
These data will enable study of the rest-frame ultraviolet morphology
of galaxies at 0z1, allowing determination of the morphological
k-correction and the location of star formation within galaxies, using
a sample that is likely to be nearly complete with multi-wavelength
photometry and spectroscopic redshifts. The results can be used to
interpret observations of higher redshift galaxies by ACS.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.) None

COMPLETED OPS REQs:
17080-2 RF Transfer Switch Scrub @ 016/16:54Z


OPS NOTES EXECUTED:
NONE

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 9 9
FGS REacq 6 6
FHST Update 15 15
LOSS of LOCK



SIGNIFICANT EVENTS:

Successfully completed bi-yearly RF Transfer Switch Scrub @ 015/16:54Z
(OR 17080-2 with attached ROP IC-06). During scheduled event, powered
ON SSA Transmitter, recorded SSAR Eb/No received from WSC, and powered
OFF SSA Transmitter. Cycled RF Transfer Switch 2 five times, powered
ON SSA Transmitter (straight-through), recorded SSAR Eb/No received
from WSC, powered OFF SSA Transmitter, started SSR recording 32 kbps
engineering data, and recorded MAR Eb/No received from WSC. Powered
OFF MA Transmitter, cycled RF Transfer Switch 1 five times, recorded
MAR Eb/No received from WSC, powered ON MA Transmitter, and stopped
SSR recording.