NASA Hubble Space Telescope Daily Report # 3659

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT # 3659

PERIOD COVERED: DOY 203

OBSERVATIONS SCHEDULED

ACS/HRC 10255

A Never Before Explored Phase Space: Resolving Close White Dwarf / Red
Dwarf Binaries

We propose an ACS Snapshot imaging survey to resolve a well-defined
sample of highly probable white dwarf plus red dwarf close binaries.
These candidates were selected from a search for white dwarfs with
infrared excess from the 2MASS database. They represent unresolved
systems {separations less than approximately 2″ in the 2MASS images}
and are distributed over the whole sky. Our HST+ACS observations will
be sensitive to a separation range {1-20 AU} never before probed by
any means. The proposed study will be the first empirical test of
binary star parameters in the post-AGB phase, and cannot be
accomplished from the ground. By resolving as few as 20 of our ~100
targets with HST, we will be able to characterize the distribution of
orbital semi-major axes and secondary star masses.

ACS/HRC/WFC 10061

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/HRC/WFC 9728

Tracing the History of Cosmic Expansion to z~2 with Type Ia Supernovae

Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating universe, an extraordinary result that needs the most
rigorous test. The case for cosmic acceleration rests on the
observation that SNe Ia at z = 0.5 are about 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
SNe Ia result attributed to grey dust or cosmic evolution of the SN Ia
peak luminosity would not show this change of sign. We have obtained a
toehold on this putative “epoch of deceleration” with SN 1997ff at z
= 1.7, and 3 more at z > 1 from our Cycle 11 program, all found and
followed by HST. However, this is too important a test to rest on just
a few objects, anyone of which could be subject to a lensed
line-of-sight or misidentification. Here we propose to extend our
measurement with observations of twelve SNe Ia in the range 1.0 < z < 1.5 or 6 such SNe Ia and 1 ultradistant SN Ia at z = 2, that will be discovered as a byproduct from proposed Treasury and DD programs. These objects will provide a much firmer foundation for a conclusion that touches on important questions of fundamental physics.

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.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration – CR Persistence Part 4

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 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 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/CCD 10023

STIS CCD Spectroscopic Flats C12

Obtain CCD flats on the STIS CCD in spectroscopic mode

STIS/CCD 10222

The Next Generation Spectral Library

We propose to complete our snapshot program to produce a Next
Generation Spectral Library of 600 stars for use in modeling the
integrated light of galaxies and clusters. This program is using the
low dispersion UV and optical gratings of STIS. The library will be
roughly equally divided among four metallicities, very low {[Fe/H] < -1.5}, low {-1.5 < [Fe/H] < -0.5}, near-solar {-0.3 < [Fe/H] < 0.1}, and super-solar {[Fe/H] > 0.2}, well-sampling the entire HR-diagram in
each bin. Such a library will surpass all extant compilations and have
lasting archival value, well into the Next Generation Space Telescope
era. Because of the universal utility and community-broad nature of
this venture, we waive the entire proprietary period.

STIS/CCD/MA1/MA2 9827

UV extinction by dust in unexplored LMC environments

The ensemble of results from studies of the UV extinction in the Milky
Way, Magellanic Clouds {MC}, M31 and M33, indicates a complex
dependence of the dust properties with environment, where starburst
activity and metallicity are relevant factors. Work in the LMC to
date, based on IUE data, has several drawbacks: a} only supergiants
could be used, b} they all have moderate extinction, c} the IUE S/N is
limited, d} the large IUE slit may include light from other sources,
such as scattered light from dust or faint companion stars, e} studies
are confined to few {extreme} environments. We propose to obtain UV
extinction curves more accurate than previous ones {from STIS spectra
of main sequence stars with higher reddening}, sampling four
environments in the LMC with different levels of star formation
activity, including the general field, hitherto unexplored. The
results will characterize the properties of dust in different
conditions, at the LMC metallicity, which is useful to interpret
integrated properties of distant galaxies, as well as GALEX upcoming
UV surveys. A complementary study is under way with FUSE in the far-UV
range. The combined results will provide insight on the properties of
small grains.

WFPC2 10071

WFPC2 CYCLE 12 Supplemental Darks Part 3/3

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.)

HSTAR 9486 – GSAcq(1,3,1) suffers Loss of Lock – recovery
successful.While review PTAS TC log from SB194O SMS processing, OTA SE
determined that this GSAcq(1,3,1), beginning at 2004.195/16:33:37,
successfully acquired FL-DV on both guide stars with Take Data flag ON
at 16:39:31. But, the Take Data flag went down within 4 seconds, the
FGSs returned to SSM control and the guide stars were acquired again,
with the Take Data flag ON at 16:41:24. No further Loss of Lock
instance was noted prior to the 17:06:07 PCPSAA. Under investigation.

HSTAR 9487 – GSAcq (3,2,3) returned to SSM control – ultimately
successful.OTA SE review of trending data revealed that FGS-2 returned
to SSM after entering Course Mode. The second attempt to enter course
mode resulted in a successful transition to Fine Lock and ultimately
successful acquisition. Under investigation.

COMPLETED OPS REQs: None

OPS NOTES EXECUTED:
1115-0 CCC IPCONFIG Connections @ 203/12:41z

                          SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq               11                         11
FGS REacq                08                         08
FHST Update            15                         15
LOSS of LOCK

SIGNIFICANT EVENTS: None