Status Report

NASA Hubble Space Telescope Daily Report # 3388

By SpaceRef Editor

June 20, 2003

Filed under Hubble Space Telescope, Space Telescope Science Institute, US

DAILY REPORT # 3388

PERIOD COVERED: DOY 170

OBSERVATIONS SCHEDULED

NICMOS 8791

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.

STIS/CCD 9100

High-Velocity Collimated Outflows and Equatorial Toroids in Cool Stars: A
Study
of V Hydrae and PI^1 Gru.

The Space Telescope Imaging Spectrograph (CCD) was used to observe the two
cool
red giant stars V Hya and PI^1 Gru that show strong observational evidence
for
the presence of high-velocity collimated outflows and equatorial toroids,
both
of which have been postulated to play significant roles in the formation of
bipolar planetary nebulae.

FOC 9340

Determination of the Distances and Masses of 3 Galactic Cepheids

We propose to continue a successful observing strategy which enabled us to
accurately measure angular separations < 10^-2” with the FOC for binaries
with
Cepheid primaries and main sequence B or A star secondaries {our accuracy
should
improve to ~10^-3” with STIS}. Once measurements are available at two
carefully
selected phases and these are combined with spectroscopic orbits, the
angular
information will enable the masses and distances for the binaries to be
determined from Newton’s laws and Euclidean geometry. The distances
determinations amount to bypassing two rungs of the cosmic distance ladder:
the
moving-cluster distance to the Hyades and main sequence fitting of clusters
containing Cepheids. The mass determinations will provide the first direct
dynamical mass measurements for Cepheids, providing sorely needed
quantitative
information on this poorly understood stage of massive star evolution.

SNAP 9356

SNAPSHOT survey of the Planetary Nebulae population of the Galactic Bulge

The spectacular structures seen in HST images of planetary nebulae {PNe} are
generally accepted as originating from hydrodynamical interactions between
stellar winds: the interacting-stellar wind model {ISW}. Traditionally, the
shaping is thought to occur after the star becomes hot enough to ionize the
PN.
But recent HST images indicate that the shaping may occur earlier, and the
newer
GISW model puts the shaping during the pre-planetary nebula evolution. The
relative importance of both models is not known: GISW shaping will account
for
some fraction of PNe, but estimates range from 15–100 during the PN phase,
especially for the youngest PNe. We here propose an HST Snapshot survey of
compact PNe in the Galactic Bulge, to test these predictions. The Bulge
provides
the only PNe population for which progenitor masses are known and nebular
ages
can be measured. In support of these HST measurements we have already
measured
velocity fields and emission line fluxes. The survey will give an unbiased
sampling of morphologies, and allow evolutionary sequences to be determined
to
test the ISW versus the GISW model. By-products of the survey will be the
determination of nebular masses, diameters and filling factors. We will also
obtain the White Dwarf mass distribution in the Bulge, and the initial-final
mass function for low-mass stars.

NICMOS 9386

Infrared Photometry of a Statistically Significant Sample of KBOs

While the discovery rate of Kuiper Belt objects is accelerating, the
physical
study of this new region of the solar system has been slowed by a lack of
basic
astrophysical data. Photometric observations of the majority of the more
than
400 known KBOs and Centaurs are rudimentary and incomplete, particularly in
the
infrared. The multicolor optical-infrared photometry that exists for a small
subset of KBOs often shows significant discrepancies between observations by
different observers. Their intrinsic faintness puts them at the practical
limits
of ground-based systems. In July 2001 we began what will be the largest
uniform
sample of optical photometry of KBOs with a WFPC2 SNAPSHOT program that will
perform accurate photometry at V, R, and I on a sample of up to 150 targets.
We
seek to greatly enhance the value of this survey by obtaining J and H
photometry
on the same sample using NICMOS. Combined optical and infrared broad band
photometry is a far more powerful tool for physical studies than is either
alone. Our sample includes objects that will be observed at thermal infrared
wavelengths by SIRTF and will be used with those data to derive the first
accurate diameters, albedos, and surface properties for a large sample of
KBOs.

ACS 9401

The ACS Virgo Cluster Survey

We propose the most comprehensive imaging survey to date of low-redshift,
early-type galaxies. Our goal is to exploit the exceptional imaging
capabilities
of the ACS by acquiring deep images — in the SDSS g^ and z^ bandpasses
— for
163 E, S0, dE, dE, N and dS0 galaxies in Virgo, the nearest rich cluster.
This
extraordinary dataset would likely constitute one of the principal legacies
of
HST, and would have widespread applications for many diverse areas of
astrophysics. Our immediate scientific objectives are threefold: {1} measure
metallicities, ages and radii for the many thousands of globular clusters
{GCs}
in these galaxies, and use this information to derive the protogalactic mass
spectrum of each galaxy; {2} measure the central luminosity and color
profile of
each galaxy, and use this information to carry out a completely independent
test
of the merging hierarchy inferred from the GCs, with the aid of N-body codes
that simulate the merger of galaxies containing massive black holes; and {3}
calibrate the z^ -band SBF method, measure Virgo’s 3-D structure, and carry
out
the definitive study of the GC luminosity function’s precision as a standard
candle. Our proposed Virgo Cluster Survey will yield a database of
unprecedented
depth, precision and uniformity, and will enable us to study the record of
galaxy and cluster formation in a level of detail which will never be
possible
with more distant systems.

ACS 9480

Cosmic Shear With ACS Pure Parallels

Small distortions in the shapes of background galaxies by foreground mass
provide a powerful method of directly measuring the amount and distribution
of
dark matter. Several groups have recently detected this weak lensing by
large-scale structure, also called cosmic shear. The high resolution and
sensitivity of HST/ACS provide a unique opportunity to measure cosmic shear
accurately on small scales. Using 260 parallel orbits in Sloan textiti
{F775W}
we will measure for the first time: beginlistosetlength sep0cm
setlengthemsep0cm
setlength opsep0cm em the cosmic shear variance on scales <0.7 arcmin, em
the
skewness of the shear distribution, and em the magnification effect.
endlist Our
measurements will determine the amplitude of the mass power spectrum
sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20, and the mass density
Omega_m with s/n=4. They will be done at small angular scales where
non-linear
effects dominate the power spectrum, providing a test of the gravitational
instability paradigm for structure formation. Measurements on these scales
are
not possible from the ground, because of the systematic effects induced by
PSF
smearing from seeing. Having many independent lines of sight reduces the
uncertainty due to cosmic variance, making parallel observations ideal.

ACS 9578

Cosmic Shear With ACS Pure Parallels. Targeted Portion.

Small distortions in the shapes of background galaxies by foreground mass
provide a powerful method of directly measuring the amount and distribution
of
dark matter. Several groups have recently detected this weak lensing by
large-scale structure, also called cosmic shear. The high resolution and
sensitivity of HST/ACS provide a unique opportunity to measure cosmic shear
accurately on small scales. Using 260 parallel orbits in Sloan i {F775W} we
will
measure for the first time: the cosmic shear variance on scales <0.7
arcmin, the
skewness of the shear distribution, and the magnification effect. Our
measurements will determine the amplitude of the mass power spectrum sigma_8
Omega_m^0.5, with signal-to-noise {s/n} ~ 20, and the mass density Omega_m
with
s/n=4. They will be done at small angular scales where non-linear effects
dominate the power spectrum, providing a test of the gravitational
instability
paradigm for structure formation. Measurements on these scales are not
possible
from the ground, because of the systematic effects induced by PSF smearing
from
seeing. Having many independent lines of sight reduces the uncertainty due
to
cosmic variance, making parallel observations ideal.

WFPC2 9589

WFPC2 Decontaminations and Associated Observations Pt. 1/3

This proposal is for the monthly WFPC2 decons. Also included are instrument
monitors tied to decons: photometric stability check, focus monitor, pre-
and
post-decon internals {bias, intflats, kspots, & darks}, UV throughput check,
VISFLAT sweep, and internal UV flat check.

WFPC2 9595

WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt3/3

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

STIS 9606

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

STIS 9608

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.

ACS 9674

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.

STIS 9708

STIS Pure Parallel Imaging Program: Cycle 11

This is the default archival pure parallel program for STIS during cycle 11.

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

ACS 9984

Cosmic Shear With ACS Pure Parallels

FLIGHT OPERATIONS SUMMARY:

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

HSTAR 9058: GS Acquisition (3,2,2) @ 170/20:04:08Z resulted in FL back up
on
FGS 2 due to SSLE on FGS 3. HST was in LOS at the
time of this event.
Under investigation.

COMPLETED OPS REQs: None

OPS NOTES EXECUTED: None

                            SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq                13                        13
FGS REacq                1                          1
FHST Update              30                         30
LOSS of LOCK

SIGNIFICANT EVENTS: None

SpaceRef Editor

SpaceRef staff editor.

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