Status Report

HST Daily Report # 3258

By SpaceRef Editor
December 6, 2002
Filed under , ,

HUBBLE SPACE TELESCOPE

DAILY REPORT # 3258

PERIOD COVERED: DOY 339

OBSERVATIONS SCHEDULED

FLIGHT OPERATIONS SUMMARY:

NICMOS 8790

NICMOS Post-SAA calibration – CR Persistence Part 1.

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.

STIS/CCD 9066

Closing in on the Hydrogen Reionization Edge of the Universe.

The Space Telescope Imaging Spectrograph (CCD) was used in parallel
constrain
the Hydrogen reionization edge in emission that marks the transition from a
neutral to a fully ionized IGM at a predicted redshifts.

FGS 9338

FGS Parallaxes of Cataclysmic Variables: Understanding Their Peculiar
Secondary
Stars

three dwarf novae. The true distances for all three objects turned out to be
substantially larger than predicted. The results for SS Cyg alone, will
challenge existing models to explain its large accretion luminosity. As part
of
that program we obtained infrared spectra to examine the spectral types of
the
secondary stars. The combination of the parallaxes, the spectra, and
existing
optical/IR photometry has revealed that the secondary stars of cataclysmic
variables {CVs} are peculiar, and are clearly affected by close-binary star
evolution. We propose a program to measure precise parallaxes for three
additional CVs {WZ Sge, RU Peg, and YZ Cnc}, whose orbital periods span a
much
larger range than explored in our previous program. This will allow us to
examine how the accretion luminosity and secondary star change with orbital
period. To do this will require 18 total HST orbits over two separate
cycles.
Twelve orbits in Cycle 10 {four per object}, and six orbits in Cycle 11
{two per
object}. Only the FGS on HST is capable of providing timely, high-precision
parallaxes on CVs of particular astrophysical interest.

ACS 9352

The Deceleration Test from Treasury Type Ia Supernovae at Redshifts 1.2 to
1.6

Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating
universe, an extraordinary result that needs a rigorous test. The case for
cosmic acceleration rests on the observation that SNe Ia at z ~ 0.5 are ~
0.25
mag fainter than they would be in a universe without acceleration. A
powerful
and straightforward way to assess the reliability of the SN Ia measurement
and
the conceptual framework of its interpretation is to look for cosmic
deceleration at z >= 1. This would be a clear signature of a mixed
dark-matter
and dark-energy universe. Systematic errors in the SN Ia result attributed
to
grey dust or cosmic evolution of the SN Ia peak luminosity would not show
this
change of sign. We have demonstrated proof of this concept with a single SN
Ia,
SN 1997ff at z = 1.7, found and followed by HST. The results suggest an
early
epoch of deceleration, but this is too important a conclusion to rest on
just
one object. Here we propose to use HST for observations of six SNe Ia in the
range 1.2 <= z <= 1.6, that will be discovered as a byproduct from proposed Treasury programs for high-latitude ACS surveys. Six objects will provide a much firmer foundation for a conclusion that touches on important questions of fundamental physics.

NICMOS 9360

Paschen-alpha Imaging of a SIRTF-Selected Nearby Galaxy Sample

We propose to carry out a NICMOS snapshot survey in the Paschen-alpha
{PAlpha}
emission line and H-band of the sample of galaxies being observed at 3.5 —
160
microns as part of SIRTF Nearby Galaxies Survey {SINGS} and a related
guaranteed
time survey of starburst galaxies. The PAlpha images, accessible only from
HST,
will be combined with groundbased HAlpha imaging to measure the extinction
in
the star-forming centers of these galaxies, and obtain robust, extinction-
corrected maps of the massive star formation rate {SFR}. The PAlpha data by
themselves will provide reliable `extinction- free’ SFRs, and a
cross-calibration of the {dust–affected} HAlpha– and UV–based SFRs. The
PAlpha–based SFR measurements will extend the SFR-vs.-gas density law
{Schmidt–law} to surface densities at least 30 times higher than what is
accessible using HAlpha–based SFR measurements alone, bridging the gap
between
normal galaxies and IR–luminous starbursts. Furthermore, the combination
of the
HST PAlpha images with the SIRTF images and spectra, as well as ancillary
ground–based UBVRIJHK images and GALEX UV images being obtained as part of
the
SINGS project, will provide a definitive study of the radiative transfer of
starlight and dust heating in star–forming galaxies. The processed NICMOS
images will be incorporated into the public SINGS Legacy Data Archive, to
enable
scores of follow-up studies by the astronomical community at large.

STIS/ACS/NICMOS 9430

The Role of Jets in Shaping Planetary Nebulae

Recent CO observations of several planetary nebulae {PN} suggest that
collimated
outflows may play a crucial role in the early shaping of these objects. The
idea
that jets may be the primary driver of the early development of some PN
represents a major shift in thinking about the evolution of these objects.
In
the past, the role of jets has been considered secondary to the interacting
winds scenario, the standard model of PN formation. We propose to use the
unique
capabilities of HST to access the importance of collimated outflows in the
development of the young PN PK166-06D1 {AFGL 618}. We have chosen
PK166-06D1 for
this study because it is in the early stages of PN formation – the time
during
which jets would have the greatest impact on PN development. We propose to
use
STIS, ACS, and NICMOS to characterize the collimated outflows present in
PK166-
06D1. The goals of this study are: 1} to characterize the interaction of the
jets with the surrounding AGB shell by determining the physical conditions
in
the outflows and the interaction regions, 2} to determine the structure of
the
surrounding AGB shell using deep optical imaging, 3} to investigate the
origin
of the collimated outflows by examining the central regions of the nebula.
We
require both the stability and high spatial resolution capabilities of HST
for
this project because we will be investigating the detailed structure of
compact
regions {< 1"}.

ACS 9453

The Age of the Andromeda Halo

With the advent of the ACS, we can cross a critical threshold in the study
of
galaxy formation: For the first time, we can resolve the old main sequence
stars
in the Andromeda halo, and thus directly determine the ages of the halo
stars in
a giant galaxy other than our own. As the nearest giant galaxy, Andromeda
offers
the best testing ground for understanding galaxy formation and evolution.
Resolution of its halo will tell us about its spread in age and metallicity,
thus providing a formation history. Via extensive simulations, we
demonstrate
that we can unambiguously characterize the halo population via a deep
F606W/F814W color-magnitude diagram reaching below the main sequence
turnoff.
The data will distinguish whether the halo formed quickly or through
protracted
infall and merging episodes, and would detect even a few percent trace of
intermediate age stars. Our field was carefully chosen to meet two criteria:
an
optimal stellar density ensuring adequate statistics while avoiding
overcrowding, and the inclusion of an Andromeda globular cluster matched to
the
peak halo metallicity. We also propose very brief observations in the same
two
bands of five Galactic globular clusters spanning a wide metallicity range,
thus
establishing population templates in the ACS photometric system that will be
used to calibrate and interpret the Andromeda data.

ACS/WFPC2 9481

Pure Parallel Near-UV Observations with WFPC2 within High-Latitude ACS
Survey
Fields

In anticipation of the allocation of ACS high-latitude imaging survey{s}, we
request a modification of the default pure parallel program for those WFPC2
parallels that fall within the ACS survey field. Rather than duplicate the
red
bands which will be done much better with ACS, we propose to observe in the
near-ultraviolet F300W filter. These data will enable study of the
rest-frame
ultraviolet morphology of galaxies at 0

NICMOS 9485

Completing A Near-Infrared Search for Very Low Mass Companions to Stars
within
10 pc of the Sun

Most stars are fainter and less massive than the Sun. Nevertheless, our
knowledge of very low mass {VLM} red dwarfs and their brown dwarf cousins is
quite limited. Unknown are the true luminosity function {LF}, multiplicity
fraction, mass function, and mass-luminosity relation for red and brown
dwarfs,
though they dominate the Galaxy in both numbers and total mass. The best way
to
constrain these relations is a search for faint companions to nearby stars.
Such
a search has several advantages over field surveys, including greater
sensitivity to VLM objects and the availability of precise parallaxes from
which
luminosities and masses can be derived. We propose to complete our
four-filter
NICMOS snapshot search for companions to stars within 10 pc. With a 10 sigma
detection limit of M_J ~ 20 at 10 pc, we can detect companions between 10
and
100 AU that are at least 9 mag fainter than the empirical end of the main
sequence and at least 6.5 mag fainter than the brown dwarf Gl 229B. When
completed, our search will be the largest, most sensitive, volume-limited
search
for VLM companions ever undertaken. Our four-filter search will permit
unambiguous identification of VLM-companion candidates for follow-up
observation. Together with IR speckle and deep imaging surveys, our program
will
firmly establish the LF for VLM companions at separations of 1-1000 AU and
the
multiplicity fraction of all stars within 10 pc.

GO 9493

Revealing the nature of low luminosity radio-galaxies with imaging
polarimetry

HST imaging of low luminosity FR I radio-galaxies allowed us to isolate for
the
first time their optical nuclear emission from that of the host galaxy.
Fluxes
of these unresolved nuclear sources strongly correlate with those of the
radio-
cores, suggesting a common non-thermal origin. The picture which emerges is
that
these radio-galaxies differ in many fundamental aspects from the other
classes
of AGN as they might be lacking the substantial BLR, thermal disk emission
and
torii, usually associated to active nuclei, probably reflecting a
fundamentally
different accretion mode. On the other hand, these results support the
identification of FR I as the misoriented population of BL Lac objects. It
is
crucial at this stage to firmly establish the synchrotron origin of these
nuclear sources. A simple and direct test can be performed by measuring
their
polarization. In case of synchrotron emission we expect to detect
significant
nuclear polarization, as routinely measured in BL Lac objects, at level of
3 –
20 We thus propose to obtain imaging polarimetry of a sample formed by the 9
nearest FR I radio- galaxies.

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 9593

WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt1/3

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

STIS 9605

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD

STIS 9607

CCD Bias Monitor – Part 1

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 9633

STIS parallel archive proposal – Nearby Galaxies – Imaging and Spectroscopy

Using parallel opportunities with STIS which were not allocated by the TAC,
we
propose to obtain deep STIS imagery with both the Clear {50CCD} and
Long-Pass
{F28X50LP} filters in order to make color-magnitude diagrams and luminosity
functions for nearby galaxies. For local group galaxies, we also include
G750L
slitless spectroscopy to search for e.g., Carbon stars, late M giants and
S-type
stars. This survey will be useful to study the star formation histories,
chemical evolution, and distances to these galaxies. These data will be
placed
immediately into the Hubble Data Archive.

ACS 9647

CCD Daily Monitor Part I

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 9650

CCD Hot Pixel Annealing

Hot pixel annealing will be performed once every 4 weeks. The CCD TECs will
be
turned off and heaters will be activated to bring the WFC detector
temperature
to about +10C. The HRC temperature will reach about 30C.This state will be
held
for approximately 24 hours, after which the heaters are turned off, the TECs
turned on, and the CCDs returned to normal operating condition. To assess
the
effectiveness of this procedure, a bias and two dark images will be taken
before
and after the annealing procedure for both WFC and HRC.

STIS 9692

STIS Pure Parallel Imaging Program: Cycle 10

NICMOS 9702

NICMOS Parallel Thermal Background

NICMOS Camera 2 pure parallel exposures in the F222M and F237M filters to
establish the stability of the HST+NCS+Instrument thermal emission. This
data will be compared against the already available Camera 3 measurements
in F222M which show an increased thermal background.

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

COMPLETED OPS REQs:

16879-0 Eclipse Management, GMT 338 @338/1039z
16880-0 FSW 2.2A RAM Installation @338/1908z

OPS NOTES EXECUTED:

911-0 Limit Management during WFPC2 Decontamination @ 338/1949z 339/0536z
1054-0 B6 AFT ES Bulkhead Temp Increase @340/0409z

                            SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq                 7                         7
FGS REacq                 7                         7
FHST Update               18                       18
LOSS of LOCK

SIGNIFICANT EVENTS: None

SpaceRef staff editor.