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14 Apr 2003

HUBBLE SPACE TELESCOPE

DAILY REPORT #3340

PERIOD COVERED: DOYS 101-103

Part 5 of 6

STIS/CCD/MA2 9166

Fossil Gaseous Halos of Massive Galaxies at z~1.

The Space Telescope Imaging Spectrograph (CCD and MA2) was used to
observe host galaxies of high-redshift, powerful radio sources that
are likely the progenitors of present-day gE and cD galaxies, and
therefore provide important laboratories in which to investigate the
formation of massive galaxies in the early Universe. Many
high-redshift radio galaxies exhibit giant, Ly-alpha halos. Similar
nebulae without associated radio sources have recently been
discovered in a galaxy overdensity at z = 3.09. The LyAlpha
luminosity of these halos is comparable to the total X-ray
luminosities of low--z X--ray clusters, and may reflect the hot,
cooling gas reservoir from which the galaxy/cluster is forming.

STIS/MA2 9465

The Cosmic Carbon Budget

Gaseous carbon drives the chemistry of, and is an important coolant
in interstellar clouds. In solid form, carbon is the second most
abundant element in interstellar dust, the key element contributing
to interstellar extinction, and the dominant heat source in some
interstellar clouds. Given the fundamental importance of this element
to interstellar cloud physics, it is surprising that only 8
measurements of gas- phase carbon abundances exist for neutral
clouds; 7 are in diffuse clouds where the least amount of chemistry
and dust incorporation are expected. The single measurement in a
translucent cloud suggests a C abundance that differs from the
diffuse clouds, but the measurement uncertainties make this
difference statistically insignificant. We, therefore, have no
information about carbon's behavior in translucent clouds, regions
dense enough for chemistry and dust growth to be important but low
enough extinction so that UV spectroscopy is possible {unlike for
molecular clouds}. We propose to measure total gas-phase C abundances
in 6 translucent clouds with our principal scientific goals being to
1} accurately determine the fraction of carbon in the gas and dust
phases in environments bridging the gap between diffuse and molecular
clouds 2} determine the relative depletions of C and O in neutral
clouds with known O-depletion enhancements and 3} explore how the
interstellar gas-phase C/H is related to extinction variations. 

WFPC2 9033

Measuring the mass distribution in the most distant, very X-ray
luminous galaxy cluster known

We propose to obtain a mosaic of deep HST/WFPC2 images to conduct a
weak lensing analysis of the mass distribution in the massive,
distant galaxy cluster ClJ1226.9+3332, recently discovered by us. At
z=0.888 this exceptional system is more X-ray luminous and more
distant than both MS1054.4-0321 and ClJ0152.7-1357, the previous
record holders, thus providing yet greater leverage for cosmological
studies of cluster evolution. ClJ1226.9+3332 differs markedly from
all other currently known distant clusters in that it exhibits little
substructure and may even host a cooling flow, suggesting that it
could be the first cluster to be discovered at high redshift that is
virialized. We propose joint HST and Chandra observations to
investigate the dynamical state of this extreme object. This project
will 1} take advantage of HST's superb resolution at optical
wavelengths to accurately map the mass distribution within 1.9 h^{-1}
50 Mpc via strong and weak gravitational lensing, and 2} use
Chandra's unprecedented resolution in the X-ray waveband to obtain
independent constraints on the gas and dark matter distribution in
the cluster core, including the suspected cooling flow region. As a
bonus, the proposed WFPC2 observations will allow us to test the
results by van Dokkum et al. {1998, 1999} on the properties of
cluster galaxies {specifically merger rate and morphologies} at z~0.8
from their HST study of MS1054.4-0321.

WFPC2 9710

POMS Test Proposal: WFII backup parallel archive proposal

This is a POMS test proposal designed to simulate scientific plans.

WFPC2 9676

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 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 paralell images of
random areas of the sky, following the recommendations of the 2002
Parallels Working Group.

WFPC2 9594

WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt2/3

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

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