Status Report

NASA Hubble Space Telescope Daily Report # 3796

By SpaceRef Editor
February 14, 2005
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NASA Hubble Space Telescope Daily Report # 3796

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT       # 3796




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.


ACS short annealing test

This program aims to verify if the annealing period for ACS CCD can be
reduced from the current 12 hours to six hours.

ACS/WFC 10429

Streaming Towards Shapley: The Mass of the Richest Galaxy
Concentration in the Local Universe

The 600 km/s motion of the Local Group {LG} with respect to the cosmic
microwave background {CMB} is now known to high accuracy. However, its
precise origin remains poorly understood. The contribution to the
motion from the pull of the rich Shapley supercluster at z = 0.048 is
particularly controversial. This extreme mass concentration contains
more than 20 Abell clusters within 35 Mpc of its very rich central
cluster A3558, and is recognized as both the optically richest and the
most X-ray luminous structure in the local {z < 0.1} universe. Yet, published values for the mass of Shapley continue to differ by an order of magnitude, and recent estimates of its pull on the LG range from negligible {20 km/s} to highly significant {300 km/s or more}. Here we propose to resolve this key issue by using ACS to measure high-precision surface brightness fluctuation {SBF} distances in order to make a direct measurement of the infall towards Shapley. We will target three Shapley foreground clusters where the infall is expected to be high {possibly 1000 km/s or more}, as well as the Shapley core, in order to test the assumption that it is at rest in the CMB. Prior to ACS, the Shapley region was unreachable for SBF, but ACS doubles the distance range of the SBF method with HST, enabling the distances to be measured to the required accuracy. The proposed measurements will place a firm limit on the largest mass fluctuation in the nearby universe and finally determine its contribution to the observed CMB dipole.

NIC3/WFPC2 10403

Ultraviolet Imaging of the UDF

The Hubble Deep Field North has uninterrupted observations at
wavelengths from Far- UV through NICMOS H-band, but the UDF goes no
bluer than B-band. We propose to complete the UDF coverage with deep
ultraviolet imaging of the Ultra-Deep Field {UDF} with the ACS-SBC in
the Far-UV {1500 Angstrom} and WFPC2 in the Near-UV {F300W}. We will
reach point source limits of ABmag=28.5, a factor of ten fainter than
the GALEX ultradeep surveys. Our dataset will add to the value of the
UDF legacy, and requires the unique capabilities of HST. In the spirit
of the UDF, we submit this proposal in the Treasury category. We
request a modest allocation of observing time for a Treasury program:
62 orbits. We will provide science quality images and photometric
catalogs to enable a range of research topics by the community. The
science goals of the team are to investigate the episode of strong
star formation activity in galaxies out to z=1, through the rest-frame
FUV luminosity function and the internal color structure of galaxies.
Far-UV number counts suggest that moderate redshift {z~0.5} starbursts
are undergoing a single, rapid burst of star-formation. We will
investigate this result by measuring the faint-end slope, alpha, of
the luminosity function. We will measure the star formation properties
of moderate redshift starburst galaxies and compare their morphologies
in the UV, optical, and near-IR. This catalog of starbursts will also
be important to the astronomical community in correlating unobscured
star-formation with the sources detected in the Spitzer Space
Telescope legacy observations of the field. With the high spatial
resolution data, will set strict limits on the flux escaping in
intermediate redshift {1 < z < 2} galaxies at wavelengths below the rest-frame Lyman limit, and thus infer the contribution of star forming galaxies at z~5 to the metagalactic ionizing radiation.

ACS/HRC/WFC/WFPC 10384 2 Focus Monitor

The focus of HST is measured from WFPC2/PC and ACS/HRC images of
stars. Multiple exposures are taken in parallel over an orbit to
determine the influence of breathing on the derived mean focus.
Observations are taken of clusters with suitable orientations to
ensure stars appear in all fields.


ACS CCDs daily monitor- cycle 13 – part 1

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This programme will be
for the entire lifetime of ACS.

NIC1 10208

NICMOS Differential Imaging Search for Planetary Mass Companions to
Nearby Young Brown Dwarfs

We propose to use the differential spectral imaging capability of
HST/NICMOS {NIC1} to search for planetary mass companions. We target
the twelve most nearby {within 30 pc}, isolated {no known close
companion}, and young {< 1Gyr} brown dwarfs. All of them have spectral type L and show signs of Lithium absorption, which clearly proves their substellar nature and youth. Planetary mass companions with masses down to 6 Jupiter masses, and at separations larger than 3 A.U. are bright enough for a direct detection with HST/NICMOS using the spectral differential imaging technique in two narrow-band filters placed on and off molecular bands. The proposed project has the potential to lead to the first direct detection of a planetary mass object in orbit around a nearby brown dwarf.

ACS/WFC/NIC3 10196

Morphologies of a new class of rest-frame optical selected high
redshift galaxies

We have obtained deep very Js, H, Ks imaging with the VLT of two
fields with excellent optical imaging, in order to study high redshift
galaxies. Using these Near-IR images, we identified a class of
galaxies with Js – Ks color larger than 2.3. Photometric redshifts and
spectroscopic follow-up showed that their mean redshift is 2.5 +- 0.7.
These galaxies are complementary to Lyman break selected galaxies: the
overlap is minimal, and the rest-frame optical colors of the Js-Ks
selected galaxies are much redder. Their contribution to the stellar
mass density is comparable to that of Lyman breaks in our fields. SED
fits and Near-IR spectroscopy of the Js-Ks selected galaxies indicate
median ages between 1 and 2 Gyr, a factor of 3-5 older than the ages
of Lyman break galaxies estimated by similar methods. They are likely
the oldest galaxies at z=2.5, and may be evolving into the most
massive galaxies at z=0. We propose to obtain images of the
spectroscopically confirmed Js-Ks galaxies with the NICMOS/NIC3 camera
in the H band. These galaxies lie the field of MS1054-03, for which we
have excellent ground based and HST optical imaging. The increased
depth and spatial resolution of the NICMOS imaging will allow us to
determine the restframe optical morphologies of the Js – Ks galaxies,
in order to study their intensity profiles and regularity, to
decompose the largest galaxies in bulges and disks, to measure scale
lengths, and to look for evidence of merging and recent star
formation. This study would provide us unique insight into the nature
of these red galaxies, their evolutionary history and their likely
descendants at low redshift.


The Star Formation History and Metallicity Evolution of M33: A
Comprehensive Study of Disk Evolution

We will obtain deep, panchromatic imaging photometry of stellar
populations in four fields ranging from 0.5 to 4 scale lengths across
the disk of the Local Group spiral M33. The observations are designed
to detect the oldest main-sequence turnoffs in three outer disk
fields, and to reach the crowding limit in the innermost field. We
will combine the photometry data with information we already have
in-hand on abundances from stars and H II regions in M33 to derive the
star formation history and metallicity evolution of the M33 disk. The
information from our four fields will allow us to obtain {1} the ages
of the oldest disk stars and the radial variation of their ages; {2}
the radial variation of the star formation history and its nature
{e.g., constant, declining, or bursting}; and {3} the metallicity
distribution in each field and the time evolution of the metallicity
gradient. Our team, an experienced mix of photometrists,
spectroscopists, and galaxy evolution theorists, will use the results
from this program to construct a comprehensive chemo- dynamical model
for the M33 disk. This detailed study of M33 will be a key in
developing an understanding of the formation and evolution of disks
that can be applied to studies of disks at both low and high redshift,
and will also yield a wealth of information on stellar populations,
chemical evolution, and star clusters that will be of great value to
future investigators.

ACS/WFC 10188

In-Depth Study of The Antennae with NICMOS and ACS

We propose new observations of “The Antennae” {NGC 4038/39}, the
nearest and youngest example of a major disk-disk merger, with NICMOS
and ACS. The long overdue NICMOS observations will allow us to
penetrate the dust in the Overlap Region, measure the P_alpha emission
and CO band strengths of young clusters, and study supernova remnants
in heavily obscured regions using [FeII] images. The high resolution
{0.05″ pixel} ACS observations will allow us for the first time to
reliably distinguish clusters from stars based on their apparent
sizes, and to potentially identify hundreds of supernova remnants that
may control the energy balance and feedback mechanisms within the ISM
{based on [SII] images}. In conjunction with our previous WFPC2, GHRS,
and STIS observations, the new data will provide answers to
fundamental questions such as: How do these clusters form and evolve?
How quickly are they destroyed and what fraction of the field stars
were formed in clusters. How many clusters are hidden by dust? How do
the clusters and associated supernovae affect the local and global
ISM? What are the dynamical masses of the clusters, and are the
stellar IMF’s truncated? Simultaneous parallel observations will also
determine whether clusters can form in the more quiescent environment
of the inner tails. A better understanding of how mergers form
tremendous numbers of clusters and stars in the local universe will
help shed light on processes that are crucial during galaxy assembly
throughout the observable universe.

ACS/HRC 10185

When does Bipolarity Impose itself on the Extreme Mass Outflows from
AGB Stars? An ACS SNAPshot Survey

Essentially all well-characterized preplanetary nebulae {PPNe} —
objects in transition between the AGB and planetary nebula
evolutionary phases – are bipolar, whereas the mass-loss envelopes of
AGB stars are strikingly spherical. In order to understand the
processes leading to bipolar mass-ejection, we need to know at what
stage of stellar evolution does bipolarity in the mass-loss first
manifest itself? Our previous SNAPshot surveys of a PPNe sample {with
ACS & NICMOS} show that roughly half our targets observed are
resolved, with well-defined bipolar or multipolar morphologies.
Spectroscopic surveys of our sample confirm that these objects have
not yet evolved into planetary nebulae. Thus, the transformation from
spherical to aspherical geometries has already fully developed by the
time these dying stars have become preplanetary nebulae. From this new
and surprising result, we hypothesize that the transformation to
bipolarity begins during the very late AGB phase, and happens very
quickly, just before, or as the stars are evolving off the AGB. We
propose to test this hypothesis quantitatively, through a SNAPshot
imaging survey of very evolved AGB stars which we believe are nascent
preplanetary nebulae; with our target list being drawn from published
lists of AGB stars with detected heavy mass-loss {from millimeter-wave
observations}. This survey is crucial for determining how and when the
bipolar geometry asserts itself. Supporting kinematic observations
using long-slit optical spectroscopy {with the Keck}, millimeter and
radio interferometric observations {with OVRO, VLA & VLBA} are being
undertaken. The results from this survey {together with our previous
work} will allow us to draw general conclusions about the onset of
bipolar mass-ejection during late stellar evolution, and will provide
crucial input for theories of post-AGB stellar evolution. Our survey
will produce an archival legacy of long-standing value for future
studies of dying stars.

ACS/HRC 10182

Towards a Comprehensive Understanding of Type Ia Supernovae: The
Necessity of UV Observations

Type Ia supernovae {SNe Ia} are very important to many diverse areas
of astrophysics, from the chemical evolution of galaxies to
observational cosmology which led to the discovery of dark energy and
the accelerating Universe. However, the utility of SNe Ia as
cosmological probes depends on the degree of our understanding of SN
Ia physics, and various systematic effects such as cosmic chemical
evolution. At present, the progenitors of SNe Ia and the exact
explosion mechanisms are still poorly understood, as are evolutionary
effects on SN Ia peak luminosities. Since early-time UV spectra and
light curves of nearby SNe Ia can directly address these questions, we
propose an approach consisting of two observational components: {1}
Detailed studies of two very bright, young, nearby SNe Ia with HST UV
spectroscopy at 13 epochs within the first 1.5 months after discovery;
and {2} studies of correlations with luminosity for five somewhat more
distant Hubble-flow SNe Ia, for which relative luminosities can be
determined with precision, using 8 epochs of HST UV spectroscopy
and/or broad-band imaging. The HST data, along with extensive
ground-based optical to near-IR observations, will be analyzed with
state-of-the-art models to probe SN Ia explosion physics and constrain
the nature of the progenitors. The results will form the basis for the
next phase of precision cosmology measurements using SNe Ia, allowing
us to more fully capitalize on the substantial past {and future}
investments of time made with HST in observations of high-redshift SNe

NIC2 10173

Infrared Snapshots of 3CR Radio Galaxies

Radio galaxies are an important class of extragalactic objects: they
are one of the most energetic astrophysical phenomena and they provide
an exceptional probe of the evolving Universe, lying typically in high
density regions but well-represented across a wide redshift range. In
earlier Cycles we carried out extensive HST observations of the 3CR
sources in order to acquire a complete and quantitative inventory of
the structure, contents and evolution of these important objects.
Amongst the results, we discovered new optical jets, dust lanes,
face-on disks with optical jets, and revealed point-like nuclei whose
properties support FR-I/BL Lac unified schemes. Here, we propose to
obtain NICMOS infrared images of 3CR sources with z<0.3 as a major enhancement to an already superb dataset. We aim to deshroud dusty galaxies, study the underlying host galaxy free from the distorting effects of dust, locate hidden regions of star formation and establish the physical characteristics of the dust itself. We will measure frequency and spectral energy distributions of point-like nuclei, expected to be stronger and more prevalent in the IR, seek spectral turnovers in known synchrotron jets and find new jets. We will strongly test unified AGN schemes and merge these data with existing X-ray to radio observations. The resulting database will be an incredibly valuable resource to the astronomical community for years to come.

NIC1 10143

Ultracool companions to the nearest L dwarfs

We propose to conduct the most sensitive survey to date for low mass
companions to nearby L dwarfs. We will use NICMOS to image targets
drawn from a volume-complete sample of 70 L dwarfs within 20 parsecs.
The combination of infrared imaging and proximity will allow us to
search for T dwarf companions at separations as small as 1.6 AU. This
is crucial, since no ultracool binaries are currently known with
separations exceeding 15 AU. Only 10 dwarfs in this sample have
previous HST observations primarily at optical wavelengths. With the
increased sensitivity of our survey, we will provide the most
stringent test to date of brown dwarf models which envisage formation
as ejected stellar embryos. In addition, our observations will be
capable of detecting binaries with mass ratios as low as 0.3, and will
therefore also test the apparent preference for equal-mass ultracool
binaries. Finally, our observations offer the best prospect to date of
detecting companions significantly cooler than the coolest t dwarf
currently known.

ACS/WFC 10135

Unveiling the Progenitors and Physics of Cosmic Explosions

GRBs and XRFs are clearly highly asymmetric explosions and require a
long-lived power source {central engine}. In contrast, nearby
core-collapse events are essentially spherical explosions. However,
the failure of spherical neutrino driven collapses has led to the idea
that asymmetric energy release is essential for the explosion. The
recent finding of a Type Ic SN in GRB 030329, the association of the
low energy event GRB 980425 with SN 1998bw, the theoretical
development discussed above and the rise of collapsar models make it
timely to consider whether all these explosions contain engines. Given
the uncertainties in theoretical modeling it is clear that
observations are needed to guide models. A priori there is little
reason to expect connection between the ultra- relativistic jet that
powers the GRB and the explosive nucleosynthesis of the ~0.5 solar
masses of Nickel-56 that powers the accompanying supernova. We propose
a comprehensive program of ACS photometric searches {and measurements}
for SNe associated with GRBs and XRFs. In concert, we will undertake
ground-based spectroscopy to determine velocity widths, and measure
engine parameters from pan- chromatic afterglow observations. Our goal
is to produce a comprehensive database of engine and SN physical
parameters against which theoretical modeling will be guided.

WFPC2 10132

UV Confirmation of New Quasar Sightlines Suitable for the Study of
Intergalactic Helium

The reionization of intergalactic helium is thought to have occurred
between redshifts of about 3 and 4. The study of HeII Lyman-alpha
absorption towards a half-dozen quasars at 2.7 < z < 3.5 demonstrates the great potential of such probes of the IGM, but the current critically-small sample limits confidence in resulting cosmological inferences. The requisite unobscured quasar sightlines to high-redshift are extremely rare, especially due to severe absorption in random intervening Lyman-limit systems, but SDSS provides hundreds of bright, new quasars at such redshifts potentially suitable for HeII studies. Our cycle 13 SNAP program proposes to verify the UV detectability of 40 new, bright, z > 2.9 SDSS quasars, but with special
emphasis on extending helium studies to the highest redshift
sightlines. Our proposed approach has already proven successful, and
additional sightlines will enable follow-up spectal observations to
measure the spectrum and evolution of the ionizing background
radiation, the density of intergalactic baryons, and the epoch of
reionization of the IGM.

FGS 10103

FGS Astrometry of a Star Hosting an Extrasolar Planet: The Mass of

We propose observations with HST/FGS to determine the astrometric
elements {perturbation orbit semimajor axis and inclination} produced
by the outermost extra-solar planet orbiting the F8V star Upsilon
Andromedae. These observations will permit us to determine the actual
mass of the planet by providing the presently unknown sin i factor
intrinsic to the radial velocity method which discovered this object.
An inclination, i = 30degrees, within the range of one very low
precision determination using reanalyzed HIPPARCOS intermediate data
products, would produce the observed radial velocity amplitude, K = 66
ms with a companion mass of ~8 M_Jupiter. Such a mass would induce in
Upsilon Andromedae a perturbation semi-major axis, Alpha = 0arcs0012,
easily within the reach of HST/FGS fringe tracking astrometry. The
proposed observations will yield a planetary mass, rather than, as
previous investigations have done, only suggest a planetary mass


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



  • 1297-0  Bay 6 Aft ES Bulkhead Temperature Increase @ 042/1045z
  • 1298-0  OTA Fitting Temperature Limit Change @ 042/1503z
  • 1299-0  Main Ring and Bay 6 Upper Limit Change @ 042/2130z
  • 1300-0  Tan Link-1 Temperature Limit change @ 042/2344z
  • 1301-0  B7 Hnycmb Dr INT Temp1 and Tunnl Structure Temp Limit Change @043/0117z
  • 1302-0  Raise TB5TNSTR Upper Temperature Limit @ 043/0712z
  • 0916-0  Tabulation of Slew Attitude Error (Miss-distance) @ 045/0039z

                            SCHEDULED     SUCCESSFUL    FAILURE TIMES 
 FGS Gsacq                  21                      21 
 FGS Reacq                  26                      26 
 FHST Update               42                      42 


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