Daily 3498 Science Only

HUBBLE SPACE TELESCOPE 

DAILY REPORT    # 3498 

PERIOD COVERED: DOYs 330-331 

OBSERVATIONS SCHEDULED 

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.

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 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 0<z<1, 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.

FGS 9879 

An Astrometric Calibration of the Cepheid Period-Luminosity Relation 

We propose to measure the parallaxes of 10 Galactic Cepheid variables.
There is no other instrument on or off the earth that can consistently
deliver HST FGS level of precision for critical parallaxes. When these
parallaxes {with 1-sigma precisions of 10% or better} are added to our
recent HST FGS parallax determination of delta Cep {Benedict et al
2002}, we anticipate determining the Period-Luminosity relation zero
point with a 0.03 mag precision. In addition to permitting the test of
assumptions that enter into other Cepheid distance determination
techniques, this calibration will reintroduce Galactic Cepheids as a
fundamental step in the extragalactic distance scale ladder. A
Period-Luminosity relation derived from solar metallicity Cepheids can
be applied directly to extragalactic solar metallicity Cepheids,
removing the need to bridge with the Large Magellanic Cloud and its
associated metallicity complications.

NIC/NIC3 9865 

The NICMOS Parallel Observing Program 

We propose to continue managing the NICMOS pure parallel program.
Based on our experience, we are well prepared to make optimal use of
the parallel opportunities. The improved sensitivity and efficiency of
our observations will substantially increase the number of
line-emitting galaxies detected. As our previous work has
demonstrated, the most frequently detected line is Halpha at
0.7<z<1.9, which provides an excellent measure of current star
formation rate. We will also detect star-forming and active galaxies
in other redshift ranges using other emission lines. The grism
observations will produce by far the best available Halpha luminosity
functions over the crucial--but poorly observed--redshift range where
galaxies appear to have assembled most of their stellar mass. This key
process of galaxy evolution needs to be studied with IR data; we found
that observations at shorter wavelengths appear to have missed a large
fraction of the star-formation in galaxies, due to dust reddening. We
will also obtain deep F110W and F160W images, to examine the space
densities and morphologies of faint red galaxies. In addition to
carrying out the public parallels, we will make the fully reduced and
calibrated images and spectra available on-line, with some
ground-based data for the deepest parallel fields included.

STIS/CCD/MA1 9848 

A SNAPSHOT Survey of Sharp-Lined Early B-Type Stars 

Although spectrum synthesis studies of the UV spectra of sharp-lined
main sequence B stars provide us with some our best determinations of
the abundances of the Fe group and neutron capture elements and the
chemical evolution in our galaxy and the Magellanic Clouds, the HST
archive is virtually devoid of high resolution spectra of the bright
nearby B stars that have become to be regarded as abundance standards.
For example, there are NO observations of HR 1886, iota Her, and tau
Her, the sharpest-lined representatives {V sin i < 5 km/s} of spectral
classes B1 V, B3 IV-V and B5 IV, and only a few tiny spectral
intervals of gamma Peg {B2 IV}. Information on the abundances of the
Fe group is important for computing opacities for stellar evolution
calculations and for determining astrophysical f-values. There are no
suitable galactic standards in the HST database to compare with recent
HST/STIS observations of B stars in the Magellanic Clouds and the
likely future observations of similar objects in M31 and other nearby
galaxies. To correct this deficiency, we propose SNAPSHOT observations
with the STIS E140M and E230M gratings of 33 of the best bright
abundance standards in nearby clusters and the galactic field. Using
this data we will determine the abundances of the Fe group and heavy
elements using the technique of spectrum synthesis with LTE and NLTE
treatments. We waive the proprietary period.

NIC3/ACS/HRC/WFC 9803 

Deep NICMOS Images of the UDF 

The ACS Ultra Deep Field {UDF} images will greatly enhance the rich
suite of deep multi-wavelength images in the Chandra Deep Field South
{CDF--S}. We propose to complete the image set with deep near-IR
NICMOS images at 1.1 and 1.6 microns over a significant fraction of
the UDF, providing a critical link between the HST ACS and SIRTF
observations. The timely addition of the near-IR images ensures that
investigators will have images that span the spectrum from X-ray to
far IR. In recognition of the value of the near IR images this
proposal is submitted as a Treasury proposal with no proprietary
period. The proposal team will deliver science quality images,
mosaiced images covering 4.9 sq arc min, and a photometric catalog
complete to an AB mag of 28.2 in both the F110W and F160W filters. The
program also delivers a parallel extremely deep ACS field, 8' away,
that reaches to within 0.6 mag of the UDF in the same filters as the
UDF. The scientific program of the proposal team focuses on the star
formation history of the universe, evolved galaxies at high redshift,
galaxies at the epoch of reionization, and the redshift evolution of
AGNs and ULIRGs. The HDF-N is currently the only field with
spatially-coincident deep HST imaging in both the optical and near-IR.
The small size of the HDF-N means that large scale structure is the
dominant error in the results from the HDF-N. Providing observations
in a field that is spatially uncorrelated is critically important. The
UDF/CDF-S fulfills that goal. The depth of the UDF ACS imaging, and
the wealth of Great Observatory and ground based observations in the
CDF-S, make these NICMOS observations uniquely valuable. An
extraordinarily rich array of science opportunities await the
community from the NICMOS UDF data.

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/HRC/WFC/STIS/CCD 9767 

Search for Black Holes in M31 Globular Clusters 

Whether globular clusters contain a central massive black hole remains
a very controversial subject today, and yet is extremely important for
theoretical models for black hole and cluster formation. Furthermore,
the existence of intermediate-mass black holes has important
implications for supermassive black hole and galactic bulge formation,
as well as providing signatures in gravitational wave detectors. We
propose to obtain high spatial resolution, long-slit spectroscopy of
two globular clusters in M31, G78 and G280. These two clusters
represent the best ones in which to constrain a central black hole.
Most importantly, both of these clusters have long central relaxation
times, and thus confusion between a central black hole and a
collection of heavy stellar remnants is alleviated. We have considered
all globular clusters in our Galaxy and in M31; STIS observations of
these two will provide the strongest limits for a black hole in any
cluster, and better than the two claims made previously in the
literature. Combined with the data for G1, these three clusters have
the three highest central velocity dispersions for any cluster in the
Local Group and will shed light on possible connections between galaxy
and globular cluster formation.

ACS/WFC 9744 

HST Imaging of Gravitational Lenses 

Gravitational lenses offer unique opportunities to study cosmology,
dark matter, galactic structure, galaxy evolution and quasar host
galaxies. They are also the only sample of galaxies selected based on
their mass rather than their luminosity or surface brightness. While
gravitational lenses can be discovered with ground-based optical and
radio observations, converting them into astrophysical tools requires
HST. HST has demonstrated that it is the only telescope that can in
each case precisely locate the lens galaxy, measure its luminosity,
color and structure, and search for lensed images of the source host
galaxy given the typical image separations of ~1''. We will obtain
ACS/WFC V and I images and NICMOS H images of 21 new lenses never
observed by HST and NICMOS H images of 16 lenses never observed by HST
in the IR. As in previous cycles, we request that the data be made
public immediately.

STIS/MA1/MA2 9739 

Are We Missing the Dominant Sites of Star Formation in Local UV-Bright
Starbursts?

We propose to explore the ages, extinctions, and masses of young
stellar clusters in four nearby dwarf starburst galaxies {He 2-10, NGC
5253, NGC 4214, and IIZw40}. We will combine available archival data
with new, high resolution HST observations from the ultraviolet to the
infrared. All four galaxies are known from ground based radio/infrared
observations to contain highly obscured, massive stellar clusters,
which dominate the far infrared flux. Despite the fact that almost all
of the infrared flux comes from regions which are obscured at UV and
optical wavelengths, these galaxies are consistent with the well known
correlation between the UV slope {beta} and the ratio of far infrared
flux to ultraviolet flux at 1600 Angstroms. Because the UV and IR
fluxes are decoupled, this observation implies that a simple
foreground screen model, where UV photons from hot stars are
reprocessed into the infrared by local dust, is not the proper
interpretation for why these galaxies follow the beta relation. We
propose to investigate the underlying mechanisms responsible for this
observed correlation in these UV bright galaxies, and explore the
implication for high redshift starbursts.

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.

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/ACS/NICMOS 9430 

The Role of Jets in Shaping Planetary Nebulae 

Recent CO observations of several planetary nebulae {PN} suggest that
collimated outflows may play a crucial role in the early shaping of
these objects. The idea that jets may be the primary driver of the
early development of some PN represents a major shift in thinking
about the evolution of these objects. In the past, the role of jets
has been considered secondary to the interacting winds scenario, the
standard model of PN formation. We propose to use the unique
capabilities of HST to access the importance of collimated outflows in
the development of the young PN PK166-06D1 {AFGL 618}. We have chosen
PK166-06D1 for this study because it is in the early stages of PN
formation - the time during which jets would have the greatest impact
on PN development. We propose to use STIS, ACS, and NICMOS to
characterize the collimated outflows present in PK166- 06D1. The goals
of this study are: 1} to characterize the interaction of the jets with
the surrounding AGB shell by determining the physical conditions in
the outflows and the interaction regions, 2} to determine the
structure of the surrounding AGB shell using deep optical imaging, 3}
to investigate the origin of the collimated outflows by examining the
central regions of the nebula. We require both the stability and high
spatial resolution capabilities of HST for this project because we
will be investigating the detailed structure of compact regions {<
1"}.

ACS/WFC 9419 

The Complete IMF of a Massive Young Cluster 

We propose to use the large improvement in sensitivity and wide-field
resolution provided by ACS to obtain for the first time the complete ~
0.1 M_Sun to ~ 100 M_Sun IMF of a single massive young cluster. We
will obtain BVI + nebular deep {V ~ 27} WFC photometry of six cluster
and one background pointings and we will use the auto-parallel
capacity of ACS to simultaneously acquire deep NUV+U+V photometry of
selected regions in the cluster. Special care has been taken to treat
all the complications which arise in the reduction of data for the
purpose of calculating the IMF of a young cluster. We have chosen as
our object of study N11 in the LMC because it arguably provides the
best combination of stellar mass range {> 40 O stars, with several O3
stars}, spatial resolution {1 WFC pixel = 0.0125 pc}, low extinction
{E{B-V} ~ 0.1}, crowding, background confusion, and nebular
contamination in comparison to other Galactic and Local Group
clusters. It also has the advantage of having two separate regions,
one which has already stopped forming stars and another one which is
still forming them, thus allowing us to search for differences in the
IMF between those two cases. The ACS data will be complemented with IR
ground-based observations obtained using Gemini South, for which we
already have been awarded time.

NICMOS 8790 

NICMOS Post-SAA calibration - CR Persistence Part 1. 

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.

WFPC2 10075 

WFPC2 CYCLE 12 Intflat and Viflat Sweeps and Filter Rotation Anomaly
Monitor

Using intflat observations, this WFPC2 proposal is designed to monitor
the pixel-to-pixel flatfield response and provide a linearity check.
The intflat sequences, to be done once during the year, are similar to
those from the Cycle 11 program 9597. The images will provide a backup
database in the event of complete failure of the visflat lamp as well
as allow monitoring of the gain ratios. The sweep is a complete set of
internal flats, cycling through both shutter blades and both gains.
The linearity test consists of a series of intflats in F555W, in each
gain and each shutter. As in Cycle 11, we plan to continue to take
extra visflat, intflat, and earthflat exposures to test the
repeatability of filter wheel motions.

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.

ACS/HRC/WFC 10042 

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/MA1 10034 

Cycle 12 MAMA Dark Monitor 

This test performs the routine monitoring of the MAMA detector dark
noise. This proposal will provide the primary means of checking on
health of the MAMA detectors systems through frequent monitoring of
the background count rate. The purpose is to look for evidence of
change in dark indicative of detector problem developing.

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 10017 

CCD Dark Monitor-Part 1 

Monitor the darks for the STIS CCD. 

STIS/CCD 10000 

STIS Pure Parallel Imaging Program: Cycle 12 

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