Status Report

NASA Hubble Space Telescope Daily Report # 3651

By SpaceRef Editor
July 12, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science




NIC2 9875

The Fundamental Plane of Massive Gas-Rich Mergers

We propose deep NICMOS H-band imaging of a carefully selected sample
of 33 luminous, late-stage galactic mergers. This program is part of a
comprehensive investigation of the most luminous mergers in the nearby
universe, the ultraluminous infrared galaxies {ULIGs}. The
high-resolution HST images will complement an extensive set of
ground-based data that include long-slit NIR spectra from a recently
approved Large VLT Programme. This unique dataset will allow us to
derive with unprecedented precision structural -and- kinematic
parameters for a large unbiased sample of objects spanning the entire
ULIG luminosity function. These data will refine the fundamental plane
of massive gas-rich mergers and enable us to answer the following
questions: {1} Do ultraluminous mergers form elliptical galaxies, and
in particular, giant ellipticals? {2} Do ULIGs evolve into optically
bright QSOs? The results from this detailed study of massive mergers
in the local universe will be relevant to understanding galaxy
formation and evolution at earlier epochs, and in particular, the
dusty sub-mm population that accounts for more than half of the star
formation at z > 1.

WFPC2 9816

Proper motion kinematics in Galactic bulge/bar fields

With this proposal we continue a successful programme to measure
proper motions in fields in the galactic bulge. We are able to reach
accuracies of ca 10km/s in transverse motion at a distance of 8kpc,
for thousands of stars per WFPC2 field. In combination with VLT
spectroscopic radial velocities and metallicity indices, we will be
able to construct a full dynamical and stellar-population model for
our Bulge. Previous fields in this programme were on the minor axis;
the fields proposed here {using first epoch observations from
1995-1998 from the archive} lie in the first quadrant, on the near
side of the Galactic bar. We also wish to establish first-epoch
observations in the 4th quadrant, where no suitable data exist so far.


The local Hubble flow and the density field within 6 Mpc

Great progress has been made recently in accurate distance
measurements of nearby galaxies beyond the Local Group based on the
luminosity of the tip of the red giant branch {TRGB}. Over the last
three years, snapshot surveys with HST have provided us with the TRGB
distances for more than a hundred nearby galaxies obtained with an
accuracy of about 10%. The local velocity field within 5 Mpc exhibits
a significant anisotropy which disagrees with a spherical
Virgo-centric flow. The local Hubble flow is very cold, with 1-D rms
deviations of ~30 km/s. Cosmological simulations with Cold Dark Matter
can only realize such low dispersions with a combination of a low mean
density of matter and a substantial component with negative pressure.
There may be a constraint on the equation of state w=-p/rho. Our
observations will concentrate on 116 galaxies whose expected distances
lie within 4 – 6 Mpc, allowing us to trace a Dark Matter distribution
in the Local Volume with twice the information currently available.
The program is a good one for SNAP mode because the order and rate
that the observations are made are not very important, as long as
there is good completion over several years.


Galaxy Evolution During Half the Age of the Universe: ACS imaging of
rich galaxy clusters

Detailed studies of nearby galaxies {z<0.05} have shown that galaxies
have very complex histories of formation and evolution involving
mergers, bursts of star formation, and morphological changes. Even so,
the global properties of the galaxies {radii, luminosities, rotation
velocities, velocity dispersions, and absorption line strengths}
follow a number of very tight {empirical} scaling relations, e.g. the
Tully-Fisher relation and the Fundamental Plane. These relations place
constraints on models for galaxy evolution. The results for nearby
galaxies rely on high signal-to-noise spectroscopy and multi-color
photometry. With the Gemini Telescopes and the Hubble Space Telescope
{HST} it is possible to carry out similar detailed studies of galaxies
at much larger redshifts, up to z~1.0, equivalent to half the age of
the Universe. We have started a project using the scaling relations
and aimed at studying the galaxy evolution over the last half of the
age of the Universe. The project is based on a large database of
spectroscopy and photometry of galaxies in 15 X-ray selected clusters
of galaxies with redshifts between 0.15 and 1.0. Spectroscopic
observations are being obtained using both Gemini Telescopes; we have
observed 6 clusters so far, covering from z=0.18 to z=0.83. We propose
to use HST/ACS to image the clusters and determine the morphologies
and measure the sizes of the galaxies. At this time we ask for 26
orbits to image four of the clusters in our sample.

STIS/MA1/MA2 9739

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

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.

ACS/WFC 9727

Exploration of the SN Ia Hubble Diagram at z > 1.2

In the spirit of a Treasury proposal, we propose to organize, and
deliver to the astronomical community, non-proprietary follow-up
observations of ~10 Type Ia supernovae at 1<z<1.7 that are expected to
be discovered in a Cycle 12 Treasury proposal. Together with the
currently available sample, this would provide a Hubble diagram with
over 20 SNe Ia in this redshift range, where it is possible to test
the current cosmological model in the epoch of deceleration: If z ~
0.5 SNe Ia are fainter due to evolution rather than an accelerating
expansion, they should continue to get fainter at even higher
redshifts. This size sample will show trends and outliers, and permit
a more rigorous treatment of the asymmetric amplification distribution
from gravitational lensing. This is a key redshift range for the
studies of dark energy that will be done with future surveys {and
future instruments now being designed}; this dataset will lay the
ground-work for these studies by establishing the simple properties of
the supernovae in this redshift range, including magnitudes, colors,
and timescales. If considered more appropriate, this proposal could be
treated as a part of a Treasury or Director’s Discretionary program,
since the data would be available to everybody immediately, and we
would welcome others who would want to work with us on it.


The Response of the White Dwarf in WZ Sge to the Unexpected July 2001

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to
observe WZ Sge, the most extreme dwarf nova and one of the closest
known cataclysmic variables, that has undergone a superoutburst in
July 2001 after 22 years in quiescence. Because of the uniqueness of
this event, two DD proposals were approved, one to observe the
outburst itself, and another for us to observe the early decline
phase. Here it is proposed to complete our fundamental study of the
response of a dwarf nova system to an outburst by continuing our UV
coverage of this most extreme outbursting system during its decline to
quiescence. This decline is expected to take more than 3 yrs, with the
most dramatic changes occurring in the first 2 years. This
once-in-a-lifetime chance to obtain high quality, high time {and
spectral} resolution FUV data as the decline progresses into the
critical transition from the disk- dominated phase to the bare white
dwarf, provides an unique opportunity to study the response of the
emerging white dwarf, whose chemical abundances, rotation and
temperature variation with time bear the imprint of this extraordinary
gigantic accretion event.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration – CR Persistence Part 4

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.

ACS/HRC 10272

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for
supernovae {SNe}, most notably our Lick Observatory Supernova Search
{LOSS}, have found hundreds of SNe, many of them in quite nearby
galaxies {cz < 4000 km/s}. Most of the objects were discovered before
maximum brightness, and have follow-up photometry and spectroscopy;
they include some of the best-studied SNe to date. We propose to
conduct a snapshot imaging survey of the sites of some of these nearby
objects, to obtain late-time photometry that {through the shape of the
light and color curves} will help reveal the origin of their lingering
energy. The images will also provide high-resolution information on
the local environment of SNe that are far superior to what we can
procure from the ground. For example, we will obtain color-color and
color-magnitude diagrams of stars in these SN sites, to determine
their progenitor masses and constraints on the reddening. Recovery of
the SNe in the new HST images will also allow us to actually pinpoint
their progenitor stars in cases where pre-explosion images exist in
the HST archive. Use of ACS rather than WFPC2 will make our snapshot
survey even more valuable than our Cycle 9 survey. This Proposal is
complementary to our Cycle 13 archival proposal, in which we outline a
plan for using existing HST images to glean information about SN

ACS/HRC 10130

Systemic Proper Motions of the Magellanic Clouds from Astrometry with
ACS: II. Second Epoch Images

We request second epoch observations with ACS of Magellanic Cloud
fields centered on the 40 quasars in the LMC and SMC for which we have
first epoch Cycle 11 data. The new data will determine the systemic
proper motion of the Clouds. An extensive astrometric analysis of the
first epoch data shows that follow-up observations with a two year
baseline will allow us to measure the proper motion of the clouds to
within 0.022 mas/year in each of the two orthogonal directions
{assuming that we can image 25 quasars, i.e., with a realistic
Snapshot Program completion rate}. The best weighted combination of
all previous measurements has a seven times larger error than what we
expect. We will determine the proper motion of the clouds with 2%
accuracy. When combined with HI data for the Magellanic Stream this
will constrain both the mass distribution in the Galactic Halo and
theoretical models for the origin of the Magellanic Stream. Previous
measurements are too crude for such constraints. Our data will provide
by far the most accurate proper motion measurement for any Milky Way

FGS 10109

The Distance and Mass of the Neutrino-Luminous White Dwarf PG 0122+200

PG 0122+200 is a pulsating hot white dwarf that is believed to radiate
more energy as neutrinos than it does as photons. We propose to
measure with FGS the trigonometric parallax of PG 0122+200 and thereby
determine its distance, luminosity, and mass. Ongoing investigations
from the ground will infer the neutrino luminosity through its effect
on the pulsation periods, thus testing standard and non-standard
lepton theory, but the stellar mass must first be known. The pulsation
spectrum of PG 0122+200 admits two alternative seismological
interpretations, each implying a different mass, luminosity, and
distance. Measurement of an accurate distance will resolve the matter
once and for all and precisely determine the stellar mass. This
project represents the first test of lepton physics in dense {log rho
= 6} plasma and is relevant to the many areas of stellar physics in
which neutrino interactions are important, including recent theories
intended to solve the solar-neutrino problem.

WFPC2 10071

WFPC2 CYCLE 12 Supplemental Darks Part 3/3

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


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/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 coronagraphic
monitoring is required to assess the changing position of the spots.

STIS/CCD 10022

STIS CCD Hot Pixel Annealing Cycle 12

The effectiveness of the CCD hot pixel annealing process is assessed
by measuring the dark current behavior before and after annealing and
by searching for any window contamination effects. In addition CTE
performance is examined by looking for traps in a low signal level
flat. Follows on from proposal 9612.

STIS/CCD 10020

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/CCD 10018

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.


The Physics of Relativistic Jets: Chandra Imaging of Extended Jets in
Gamma-loud Blazars

Extended jets have been a key target for Chandra yet only recently has
the kpc-scale jet physics been compared to that of the inner,
parsec-scale jets. Such a comparison reveals the jet deceleration,
power dissipation, pressure gradient, and confinement mechanism —
all essential ingredients for understanding the relativistic jets that
characterize radio- loud AGN. Currently, few data exist to make this
comparison. We propose to double the sample, with Chandra observations
of 4 gamma-loud blazars: 0954+556 and 1229-021, the only 2 bright
radio jets not yet observed by Chandra; and 0208-512 and 3C 454.3,
observed in A03 with much too short exposures. We also propose HST
multi-band ACS imaging of jet knots in 0208-512, 0954+556 and 3C


Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be

HSTAR 9478: GS Acquisition (2,1,1) @ 193/15:33:55Z ended in FL backup
on FGS 2 due SSLE on FGS 1 @ 193/15:37:39Z. Under investigation.

17224-0 – Set up ACS Memory Monitor @ 191/1857z


                         SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq             26                           26
FGS REacq             22                           22
FHST Update          37                           37


Successfully set-up ACS memory monitor @ 191/18:57Z (OR 17224 with COP
20.28, Step 2). Stored commanding updated a constant term in the ACS
Filter Wheel 2 Resolver Fourier correction algorithm during the ACS
safemode recovery. This action verifies the new constant and restores
the memory monitor on Filter Wheel 2 raw resolver counts.

SpaceRef staff editor.