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Daily 3820



 
 
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Old March 21st 05, 04:58 PM
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Default Daily 3820

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3820

PERIOD COVERED: DOYs 77-79

OBSERVATIONS SCHEDULED

NIC1/NIC2/NIC3 8792

NICMOS Post-SAA calibration - CR Persistence Part 3

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/WFC/WFPC2 10424

The White Dwarf Cooling Age and Dynamical History of the Metal-Poor
Globular Cluster NGC 6397

We propose to determine the white dwarf cooling age in the nearest
metal-poor {[Fe/H]=- 2} globular cluster, NGC 6397. This globular
cluster provides the best opportunity to test the white dwarf cooling
age in such a metal-poor system and at the same time provide a
comparison with the more metal-rich cluster {M4} which we recently
successfully observed with HST. Any {or even no} age difference
between these clusters will be important in understanding the
age-metallicity relation for these systems which reflects the star
formation history in the early Galaxy. The absolute age is an
important cosmological constraint. We expect to be able to detect age
DIFFERENCES between these clusters at the 0.5 Gyr level and absolute
ages should be accurate to 1.0 Gyr. In addition, and in contrast with
M4, NGC 6397 is highly dynamically evolved, has a collapsed core, and
the distribution of its white dwarfs throughout the cluster have
almost certainly been modified by dynamical processes. We are using
N-body simulations specifically developed for this cluster to
understand these modifications and to include their effects in our
measurement of the white dwarf luminosity function and cooling age.
Among the dynamical questions we expect to answer with this proposal
a 1} what was the primordial binary frequency in NGC 6397? 2} can
we explain the high central concentration with a population of massive
white dwarfs and/or neutron stars? 3} do we see sufficient central
binaries to reverse the core collapse of the cluster?

ACS/HRC/WFC 10399

Accurate and Robust Calibration of the Extragalactic Distance Scale
with the Maser Galaxy NGC4258 II

The extragalactic distance scale {EDS} is defined by a comparison of
Cepheid Period- Luminosity {PL} relations for nearby galaxies and the
LMC, whose uncertain distance is thereby the SOLE anchor. Studies of
masers orbiting the central black hole in NGC4258 have provided the
most accurate extragalactic distance ever {7.2+/-0.5 Mpc}, and new
radio data and analysis techniques will reduce the uncertainty to
3.5% {0.07 mag} by 2005. Since this distance is well determined and
based on geometric arguments, NGC4258 can provide a much needed new
anchor for the EDS. Ultimately, the combination of an independent
measurement of H0 and measurements of CMB fluctuations {e.g., WMAP}
can be used to directly constrain cosmological parameters including
the equation of state of dark energy. In our Cycle 12 proposal, we
defined a program spanning two cycles. The Cycle 12 portion was
accepted. We have acquired WFC images and are constructing well
sampled PL relations in 3 colors {BVI}. The purpose of the Cycle 13
observations is to address systematic sources of error and is crucial
for the success of the entire program. To disentangle the effects of
reddening and metallicity, and to characterize the effects of
blending, we require 50 orbits to obtain H-band photometry
{NICMOS/NIC2} and high resolution images {ACS/HRC}.

ACS/HRC 10377

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.

ACS/HRC/WFC 10367

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.

NIC3 10337

The COSMOS 2-Degree ACS Survey NICMOS Parallels

The COSMOS 2-Degree ACS Survey NICMOS Parallels. This program is a
companion to program 10092.

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
environments.

NIC2 10176

Coronagraphic Survey for Giant Planets Around Nearby Young Stars

A systematic imaging search for extra-solar Jovian planets is now
possible thanks to recent progress in identifying "young stars near
Earth". For most of the proposed young {~ 30 Myrs} and nearby {~ 60
pc} targets, we can detect a few Jupiter-mass planets as close as a
few tens of AUs from the primary stars. This represents the first time
that potential analogs of our solar system - that is planetary systems
with giant planets having semi-major axes comparable to those of the
four giant planets of the Solar System - come within the grasp of
existing instrumentation. Our proposed targets have not been observed
for planets with the Hubble Space Telescope previously. Considering
the very successful earlier NICMOS observations of low mass brown
dwarfs and planetary disks among members of the TW Hydrae Association,
a fair fraction of our targets should also turn out to posses low mass
brown dwarfs, giant planets, or dusty planetary disks because our
targets are similar to {or even better than} the TW Hydrae stars in
terms of youth and proximity to Earth. Should HST time be awarded and
planetary mass candidates be found, proper motion follow-up of
candidate planets will be done with ground-based AOs.

ACS/WFC 10174

Dark-matter halos and evolution of high-z early-type galaxies

Gravitational lensing and stellar dynamics provide two complementary
methods to determine the mass distribution and evolution of luminous
and dark-matter in early-type {E/S0} galaxies. The combined study of
stellar dynamics and gravitational lensing allows one to break
degeneracies inherent to each method separately, providing a clean
probe of the internal structure of massive galaxies. Since most lens
galaxies are at redshifts z=0.1-1.0, they also provide the required
look-back time to study their structural and stellar-population
evolution. We recently analyzed 5 E/S0 lens galaxies between z=0.5 and
1.0, combining exquisite Hubble Space Telescope imaging data with
kinematic data from ground-based Keck spectroscopy, placing the first
precise constraints on the dark- matter mass fraction and its inner
slope beyond the local Universe. To expand the sample to ~30 systems
-- required to study potential trends and evolution in the E/S0 mass
profiles -- we propose to target the 49 E/S0 lens-galaxy candidates
discovered by Bolton et al. {2004} from the Sloan Digital Sky Survey
{SDSS}. With the average lens rate being 40% and some systems having a
lensing probability close to unity, we expect to discover ~20 strong
gravitational lenses from the sample. This will triple the current
sample of 9 E/S0 systems, with data in hand. With the sample of 30
systems, we will be able to determine the average slope of the
dark-matter and total mass profile of E/S0 galaxies to 10% and 4%
accuracy, respectively. If present, we can simultaneously detect 10%
evolution in the total mass slope with 95% confidence. This will
provide unprecedented constraints on E/S0 galaxies beyond the local
Universe and allow a stringent test of their formation scenarios and
the standard cosmological model.

NIC2 10169

Star Formation in Luminous Infrared Galaxies: giant HII Regions and
Super Star Clusters

Luminous Infrared Galaxies {LIRGs, LIR = 10^11-10^12Lsol} and
Ultraluminous Infrared Galaxies {LIR10^12Lsol} account for
approximately 75% of all the galaxies detected in the mid-infrared in
the redshift range z=0-1.5. In the local universe it is found that
LIRGs are predominantly powered by intense star formation {SF}.
However, the physical conditions and processes governing such dramatic
activity over scales of tens to a few hundred parsecs are poorly
known. In the last decade HST has been playing a significant role,
mainly with the discovery of super star clusters {SSCs}, and more
recently, giant HII regions. Based on observations of a few LIRGs, we
found that these giant HII regions and associated SSCs appear to be
more common in LIRGs than in normal galaxies, and may dominate the
star formation activity in LIRGs. A larger sample is required to
address fundamental questions. We propose an HST/NICMOS targeted
campaign of a volume limited sample {v5200km/s} of 24 LIRGs. This
proposal will probe the role of giant HII regions in the overall
energetics of the current star formation, their relation to SSCs, and
the dependence of star formation properties on other parameters of
LIRGs. Such detailed knowledge of the SF properties of LIRGs in the
local universe is essential for understanding galaxies at high
redshift.

NIC3 10150

NICMOS observations of A1689

The potential of galaxy clusters as ``cosmic telescopes'' has been
known for a long time, but practical results in the pre-ACS era have
been scarce due to two main problems: the uncertainty in determining
the magnification distribution of the cluster {the ``optics'' of the
instrument} and the presence of numerous bright cluster galaxies which
cover the field of view and hinder the detection of background
galaxies. We have developed techniques to solve these two problems
working with our ACS observations of A1689, the most powerful lens in
the sky, and for the first time we have been able to determine the
"specifications" of a cosmic telescope with a useful level of
precision, thanks to the detection and identification of more than 100
multiple images with reliable redshift information. We propose to
observe the high magnification region in the A1689 field in the F110W
band with a 3x3 mosaic of NIC3 pointings; the resulting image will
reach a lens-corrected limiting magnitudes of 29.5 for point sources,
surpassing in depth the UDF NICMOS observations and providing an
unique dataset with multiple scientific returns.

FGS 10106

An Astrometric Calibration of the Cepheid Period-Luminosity Relation

We propose to measure the parallaxes of 10 Galactic Cepheid variables.
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.

FGS 10104

Calibrating the Mass-Luminosity Relation at the End of the Main
Sequence

We propose to use HST-FGS1R to calibrate the mass-luminosity relation
{MLR} for stars less massive than 0.2 Msun, with special emphasis on
objects near the stellar/brown dwarf border. Our goals are to
determine M_V values to 0.05 magnitude, masses to 5 than double the
number of objects with masses determined to be less than 0.20 Msun.
This program uses the combination of HST-FGS3/FGS1R at optical
wavelengths and ground-based infrared interferometry to examine
nearby, subarcsecond binary systems. The high precision measurements
with HST-FGS3/FGS1R {to 1 mas in the separations} for these faint
targets {V = 10--15} simply cannot be equaled by any ground based
technique. As a result of these measurements, we are deriving high
quality luminosities and masses for the components in the observed
systems, and characterizing their spectral energy distributions from
0.5 to 2.2 Mum. Several of the objects included have M 0.1 Msun,
placing them at the very end of the stellar main sequence. Three of
the targets are brown dwarf candidates, including the current low mass
record holder, GJ 1245C, with a mass of 0.062 +/- 0.004 Msun. The
payoff of this proposal is high because all 10 of the systems selected
have already been resolved with HST- FGS3/FGS1R during Cycles 5--10
and contain most of the reddest objects for which masses can be
determined.

ACS/WFC/WFPC2 10092

The COSMOS 2-Degree ACS Survey

We will undertake a 2 square degree imaging survey {Cosmic Evolution
Survey -- COSMOS} with ACS in the I {F814W} band of the VIMOS
equatorial field. This wide field survey is essential to understand
the interplay between Large Scale Structure {LSS} evolution and the
formation of galaxies, dark matter and AGNs and is the one region of
parameter space completely unexplored at present by HST. The
equatorial field was selected for its accessibility to all
ground-based telescopes and low IR background and because it will
eventually contain ~100, 000 galaxy spectra from the VLT-VIMOS
instrument. The imaging will detect over 2 million objects with I 27
mag {AB, 10 sigma}, over 35, 000 Lyman Break Galaxies {LBGs} and
extremely red galaxies out to z ~ 5. COSMOS is the only HST project
specifically designed to probe the formation and evolution of
structures ranging from galaxies up to Coma-size clusters in the epoch
of peak galaxy, AGN, star and cluster formation {z ~0.5 to 3}. The
size of the largest structures necessitate the 2 degree field. Our
team is committed to the assembly of several public ancillary datasets
including the optical spectra, deep XMM and VLA imaging, ground-based
optical/IR imaging, UV imaging from GALEX and IR data from SIRTF.
Combining the full-spectrum multiwavelength imaging and spectroscopic
coverage with ACS sub-kpc resolution, COSMOS will be Hubble's ultimate
legacy for understanding the evolution of both the visible and dark
universe.

FLIGHT OPERATIONS SUMMARY:

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

HHSTAR 9745 NICMOS 663 Mech PAM sensor not enabled @03/20/05 11:18 on
day 080/03:18:38 the SIC&dh received a NICMOS 663 status buffer
message. P = 0, T = 62270. The description was An attempt to move the
Pam X-tilt, Y-tilt or Focus mechanism was made without enabling limits
checking of the Pam sensor. Under investigation.

COMPLETED OPS REQs:
17406-0 -Configure NICMOS PAM @ 080/0724z

OPS NOTES EXECUTED:
1320-1 - One Time Cleanup of SI Limits @ 079/2011z
1321-1 - SI Limits Management @ 079/2020z

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS Gsacq 27 27
FGS Reacq 21 21
FHST Update 38 38
LOSS of LOCK

SIGNIFICANT EVENTS:

NICMOS was successfully transitioned from SAA-Operate to Boot, then
transitioned back up to SAA-Operate around 080/00:10 UT. The
transition from Boot to SAA-Operate activated the NICMOS flight
software version 4.0Ce, which was loaded into EEPROM via realtime
commanding during days 067 through 069.



 




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