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Daily 3593



 
 
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Old April 16th 04, 04:27 PM
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Default Daily 3593

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3593

PERIOD COVERED: DOY 106

OBSERVATIONS SCHEDULED

ACS/HRC/WFC 10060

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/WFC 9765

The Dusty ISM Substructure in Nearby Spiral Galaxies

We propose an ACS V&I imaging snapshot survey of all nearby edge-on
spiral galaxies in order to measure the small scale structures in
their dust extinction down to the 10pc scale. Dust and molecular gas
are tightly coupled and therefore HST high resolution reddening maps
can reveal information about the cold ISM phase on a scale
inaccessible from the ground by any other means. We have recently
discovered a sudden change in dust lane properties using ground-based
data; all galaxies with rotation speeds in access of 120km/s show dust
lanes, but none of the slower rotators does. This transition may be
caused by a sudden change in the state of the multiphase ISM, and HST
resolution imaging is needed to fully quantify this effect. Analysis
will consist of full radiative transfer modeling of dust extinction
with realistic, fractal like substructure and power spectrum analysis
of the structure from the global to the 10pc scale. By observing a
sample of galaxies with a range in structural parameters we can
quantify how the cold ISM structure changes as function of radius,
rotation speed, local surface density, et cetera. This information is
duly needed with SIRTF soon providing a wealth of information on dust
absorption, but lacking the resolution to determine the small scale
distribution of the dust.

ACS/WFC/WFPC2 9822

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.

FGS 9879

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 9961

The Masses and Luminosities of Population II Stars

Very little is currently known concerning the mass-luminosity relation
{MLR} of Population II stars. However, with the advent of the
Hipparcos Catalogue, improved distances to many spectroscopic binaries
known to be Pop II systems are now available. After surveying the
literature and making reasonable estimates of the secondary masses, we
find 13 systems whose minimum separation should be larger than the
resolution limit of FGS1. Because of the expected magnitude
differences and separations, it is not possible to resolve the systems
from the ground. We therefore propose FGS observations of the sample.
In combination with the known spectroscopic orbits and Hipparcos
distances, these observations will yield up to 26 precise stellar mass
determinations of metal-poor stars, if all systems are resolved and
the relative orbits are determined. A combination of FGS data and
ground-based observations will lead to component luminosities and
effective temperatures. This program will allow for a significantly
better understanding of the Pop II main sequence, which in turn will
lead to better ages and distances of the galactic globular clusters,
and a Pop II MLR will be constructed for the first time.

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
0.7z1.9, 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.

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.

NIC1/NIC2/NIC3 9993

Cycle 12 NICMOS dark current, shading profile, and read noise
monitoring program

The purpose of this proposal is to monitor the dark current, read
noise, and shading profile for all three NICMOS detectors throughout
the duration of Cycle 12. This proposal is an essentially unchanged
continuation of PID 9636 which cover the duration of Cycle 11.

NIC2 9845

NICMOS Confirmation of a Young Planetary-Mass Companion

We have recently discovered a strong candidate for a planetary-mass
{~10 Mjup} companion to a young Sun-like star, based on near-IR
imaging and spectroscopy with the Keck and Subaru adaptive optics {AO}
systems. While the ground-based data strongly suggest that the
candidate has a very low effective temperature, and hence a very low
mass, they are not definitive. We propose to obtain NICMOS
coronagraphy to measure the companion's 1.9um water-band absorption.
This feature is a distinct signature of very cool objects and is
unobservable from the ground. The combined ground-based and
space-based data set will determine whether the companion has a very
low temperature, and hence if it is the lowest mass companion found to
date by direct imaging.

NIC3 9999

The COSMOS 2-Degree ACS Survey NICMOS Parallels

The COSMOS 2-Degree ACS Survey NICMOS Parallels. This program is a
companion to program 9822.

STIS 9783

The Ages of Nuclear Star Clusters in Early-type Spiral Galaxies

We propose to obtain STIS G430L spectra of the previously identified
nuclear star cluster in a sample of 16 spiral galaxies of early to
intermediate Hubble type. HST's spatial resolution is required to
separate the nuclear cluster from the underlying galaxy bulge.
Analysis of the spectra with population synthesis methods will reveal
the cluster ages. We will use the age distribution to constrain the
duty cycle of nuclear cluster formation. Comparison of the results to
those for a larger sample of nuclear clusters in late-type, bulgeless
galaxies will allow us to investigate possible differences between the
formation mechanisms of nuclear clusters in early and late Hubble
types. Such differences might be expected because galaxy bulges show a
dichotomy: in late Hubble types, the surface brightness profiles are
best described by an exponential, while they follow a de Vaucouleurs
law in earlier types. Although the reason for this dichotomy is still
unknown, it is plausible that galaxy bulges have different formation
mechanisms at the two ends of the Hubble sequence. We know that {1}
nuclear cluster formation is linked to the funneling of gas towards
the nucleus via gravitational torques from stellar bars, {2} a nuclear
mass concentration can make bars unstable, and {3} unstable bars can
form bulges. Therefore, the age distribution of nuclear star clusters
contains important clues to the evolution of galaxy centers and
promises new insight into the origin of the Hubble sequence.

STIS/CCD 10018

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

STIS/CCD 10020

CCD Bias Monitor - Part 2

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 10024

STIS CCD Imaging Flats C12

Investigate flat-field stability over a bimonthly period.

STIS/CCD/MA1 9724

Towards a global understanding of accretion physics - Clues from an UV
spectroscopic survey of cataclysmic variables

Accretion inflows and outflows are fundamental phenomena in a wide
variety of astrophysical environments, such as Young Stellar Objects,
galactic binaries, and AGN. Observationally, cataclysmic variables
{CVs} are particularly well suited for the study of accretion
processes. We are currently carrying out a Cycle 11 STIS UV
spectroscopic snapshot survey of CVs to fully exploit the diagnostic
potential of these objects for our understanding of accretion physics.
While the data obtained so far are of excellent quality, the number of
targets that will be observed in Cycle 11 is too small for a
statistically significant analysis {only 19 objects out of our 149
accepted Cycle 11 snapshot targets have been observed at the time of
writing}. We propose here to extend this survey into Cycle 12,
building a homogenous database of accretion disc and wind outflow
spectra covering a wide range of mass transfer rates and binary
inclinations. We will analyze these spectra with state-of-the-art
accretion disc model spectra {SYNDISK}, testing our current knowledge
of the accretion disc structure, and, thereby, providing new insight
into the so far not well understood process of viscous dissipation. We
will use our parameterised wind model PYTHON for the analysis of the
radiation driven accretion disc wind spectra, assessing the
fundamental question whether the mass loss rate correlates with the
disc luminosity. In addition, our survey data will identify a number
of systems in which the white dwarf significantly contributes to the
UV flux, permitting an analysis of the impact of mass accretion on the
evolution of these compact stars. This survey will triple the number
of currently available high-quality accretion disc / wind outflow /
accreting white dwarf spectra, and we waive our proprietary rights to
permit a timely use of this database.

STIS/MA1 9790

Separating Activity and Accretion in T Tauri Stars

Due to their unique evolutionary state, the naked {non-accreting} T
Tauri stars {NTTS} are the only real proxies for what the underlying
magnetically active star of a classical TTS {CTTS} system looks like.
Comparative analysis then allows us to separate stellar properties
from accretion properties in CTTS. In addition, the late-type NTTS are
excellent candidates for studying rotation-activity relationships in
fully convective stars and probing the properties of turbulent
dynamos. With the limited data currently available, NTTS appear to be
very magnetically active stars with higher than expected H-alpha/X-ray
flux ratios but lower transition region fluxes relative to other
active stars. However, the data are very incomplete. We will use
HST-STIS observations of transition region line fluxes on 11 fully
convective NTTS to establish the level and structure of dynamo
generated emission in these young stars. In principal, these far
ultraviolet emission lines are sensitive diagnostics of mass accretion
onto CTTS, since accretion shocks on the stellar surface should
produce substantial emission measure at 10^5 - 10^6 K. However, it is
imperative that we first understand the emissions from NTTS before we
can use these lines to study accretion onto CTTS.

WFPC2 10070

WFPC2 CYCLE 12 Supplemental Darks Part 2/3

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

FLIGHT OPERATIONS SUMMARY:

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

COMPLETED OPS REQs:
17124-0 - FSW 2.5B EEPROM Installation @ 106/1332z
17122-0 - FSW 2.5B On-Orbit Verification (thru step E) @ 106/2126z

OPS NOTES EXECUTED: None

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 9 9
FGS REacq 5 5
FHST Update 18 18
LOSS of LOCK

SIGNIFICANT EVENTS:

Successfully completed installation of FSW 2.5b EEPROM (OR 17124 with
attached script) The FSW 2.5b EEPROM load was completed @
106/12:11:30Z, post-installation EEPROM memory dump was completed @
106/13:13:40Z and subsequently verified by FSW.

FSW 2.5b on-orbit verification continued following the EEPRO
installation (OR 17122). PN format was successfully acquired from
106/16:56Z - 17:09Z to verify the 10 Hz. Magnetic Field model. The
first FHST 1 OBAD with FHST in simultaneous Rate Control was
successfully performed @ 106/19:39Z, mapping 4 stars. The second FHST
3 OBAD with FHST 1 in simultaneous Rate Control was successfully
performed @ 106/21:15Z, mapping 6 stars. All FSW functions executed
nominally, SAC is in the process of comparing the results of both
OBADs to the FSW table dumps captured. Verification activities will
resume at ~ 107/12:58Z with Rate Control monitoring periods on FHST 2.




 




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