HST Daily Report #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.




Jacques :-)

Editor: www.spacepatches.info