NASA Hubble Space Telescope Daily Report # 3405

DAILY REPORT # 3405

PERIOD COVERED: DOY 196

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.

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.

STIS/CCD/MA1 9410

The Galactic Warm Ionized Medium: the First Direct Measures of its
Ionization
and Abundances

The warm ionized medium {WIM} is the dominant gaseous component of the
Galactic
halo and represents an important sink of the radiative and kinetic energy
output
of stars and supernovae, though the source of its ionization remains
unknown. We
will use stis spectroscopy of the post-AGB stars ROB 162 and ZNG 1 in the
globular clusters NGC 6397 and Messier 5 to measure directly the abundances
and
ionization states of several key metals in the Galactic WIM. These sight
lines
are unique: because the two clusters also contain pulsars with published
radio
dispersion measurements, these are the only sight lines for which we can
derive
the column densities of both HI, em and ionH2, as well as the columns of
multiple ionization stages of the important metals S, P, and Fe. We will
use the
proposed stis observations with existing use data to derive the total
gas-phase
abundances of S, P, and Fe for the material along these sight lines with no
ionization uncertainties. We will directly measure the ionization fractions
of S
and P in the WIM. We will also infer the dust content of the WIM. Our study
of
the ionization state and dust content of the WIM will provide the best yet
constraints for models of this gas. Our work will also provide the best
constraint for the fundamental “cosmic” reference abundance {averaged over
these sight lines} of the undepleted elements S and P.

ACS 9482

ACS Pure Parallel Lyman-Alpha Emission Survey {APPLES}

Ly-alpha line emission is an efficient tool for identifying young galaxies
at
high redshift, because it is strong in galaxies with young stars and little
or
no dust — properties expected in galaxies undergoing their first burst of
star- formation. Slitless spectroscopy with the ACS Wide-Field Camera and
G800L
grism allows an unmatched search efficiency for such objects over the
uninterrupted range 4 <~ z <~ 7. We propose the ACS Pure Parallel Ly-alpha
Emission Survey {“APPLES”}, to exploit this unique HST capability and so
obtain the largest and most uniform sample of high redshift Ly-alpha
emitters
yet. Parallel observations will allow this survey to be conducted with
minimal
impact on HST resources, and we will place reduced images and extracted
spectra
in the public domain within three months of observation. We aim to find ~
1000
Ly-alpha emitters, 5 times the biggest current sample of Ly-alpha emitters.
This
unprecedented sample will provide robust statistics on the populations and
evolution of Ly-alpha emitters between redshifts 4–7; a robust measurement
of
the reionization redshift completely independent of the Gunn-Peterson
trough;
spatial clustering information for Ly-alpha emitters which would let us
probe
their bias function and hence halo mass as a function of redshift; many
galaxies
at redshift exceeding 6; and lower redshift serendipitous discoveries.

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.

STIS 9615

Cycle 11 MAMA Dark Monitor

This test performs the routine monitoring of the MAMA detector dark noise.
This
proposal will provide the primary means of checking on health of the MAMA
detectors systems through frequent monitoring of the background count rate.
The
purpose is to look for evidence of change in dark indicative of detector
problem
developing.

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 9786

The Next Generation Spectral Library

We propose to continue the Cycle 10 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] lt -1.5}, low {[Fe/H] -1.5 to -0.5},
near-solar
{[Fe/H] -0.3 to 0.1}, and super-solar {[Fe/H] gt 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.

ACS/WFC 9788

A Narrow-band Snapshot Survey of Nearby Galaxies

We propose to use ACS/WFC to conduct the first comprehensive HST narrow-band
{H-alpha + [N II]} imaging survey of the central regions of nearby
bulge-dominated disk {S0 to Sbc} galaxies. This survey will cover, at high
angular resolution extending over a large field, an unprecedented number of
galaxies representing many different environments. It will have important
applications for many astrophysical problems of current interest, and it
will be
an invaluable addition to the HST legacy. The observations will be conducted
in
snapshot mode, drawing targets from a complete sample of 145 galaxies
selected
from the Palomar spectroscopic survey of nearby galaxies. Our group will
use the
data for two primary applications. First, we will search for nuclear
emission-line disks suitable for future kinematic measurements with STIS, in
order to better constrain the recently discovered relations between black
hole
mass and bulge properties. Preliminary imaging of the type proposed here
must be
done, sooner or later, if we are to make progress in this exciting new
field.
Second, we will investigate a number of issues related to extragalactic star
formation. Specifically, we will systematically characterize the properties
of H
II regions and super star clusters on all galactic scales, from
circumnuclear
regions to the large-scale disk.

ACS/WFC 9789

The Distance to the Pleiades

Despite its fundamental importance to stellar astrophysics, the distance to
the
Pleiades open cluster remains in great dispute. Main-sequence fitting
results in
a distance of 132.3 +/- 1.9 pc, while the Hipparcos average parallax for
Pleaides member stars gives a distance of 116.4 +/- 2.9 pc. If the Hipparcos
distance is to be believed, our current understanding of stellar
astrophysics is
dramatically incomplete. On the other hand, it has been proposed that the
Hipparcos parallax measurement to the Pleiades suffers systematic
uncertainties
which result in the discrepancy with the main-sequence fitting technique.
The
question will remain open until an independent distance measurement to the
Pleiades cluster is performed. We will use ACS imaging to determine the
parallax
to the Pleiades to an accuracy of about 1.5%. This will resolve the current
controversy over the distance to the cluster once and for all.

NIC2 9801

Are OH/IR Stars the Youngest post-AGB stars? A NICMOS Imaging Survey

Essentially all well-characterized preplanetary nebulae {PPNe}– objects in
transition between the AGB and planetary nebula evolutionary phases – are
bipolar, whereas the mass-loss envelopes of AGB stars are strikingly
spherical.
In order to understand the processes leading to bipolar mass-ejection, we
need
to know at what stage of stellar evolution does bipolarity in the mass-loss
first manifest itself. We have recently hypothesized that most OH/IR stars
{evolved mass- losing stars with OH maser emission} are very young PPNe. We
are
conducting a multiwavelength survey program of imaging and spectroscopic
observations of such objects, using a large, morphologically unbiased sample
selected using IRAS 12-to-25 micron colors. Our ongoing HST/SNAP imaging
survey
of the optically bright half of this sample with WFPC2 and ACS is highly
succesful: 19/32 objects observed are extended with bipolar/multipolar
shapes
{remaining objects are unresolved}. Slightly more than 50% of our sample are
optically too faint or undetected but have strong near-IR counterparts — we
therefore propose a NICMOS SNAPshot imaging survey of these optically-faint
OH/IR stars. These observations are crucial for determining how and when the
bipolar geometry asserts itself. The results from our NICMOS survey
{together
with the WFPC2/ACS survey} will allow us to draw general conclusions about
the
onset of bipolar mass-ejection during late stellar evolution. Our
complementary
program of interferometric mapping of the OH maser emission in our sources
is
yielding kinematic information with spatial resolution comparable to that
in the
HST images. The HST/radio data will provide crucial input for theories of
post-AGB stellar evolution. In addition, these data will also indicate
whether
the multiple concentric rings, "searchlight beams”, and truncated
equatorial
disks recently discovered with HST in a few PPNe, are common or rare
phenomena.

ACS 9984

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.

FLIGHT OPERATIONS SUMMARY:

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

COMPLETED OPS REQs: None

OPS NOTES EXECUTED:
1133-1 – Set All CCC V/T Level 2 Limit Values @ 196/1515z
1134-1 – Adjust ACS Error Count Limit @ 196/1600z

                           SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq               13                       13
FGS REacq               4                         4
FHST Update             20                       20
LOSS of LOCK

SIGNIFICANT EVENTS:

Completed HSTUPS Release 14, Version 4 functionality testing with the
ANCC 196/12:00Z – 21:15Z. Connected to the ANCC, sent a 7-day schedule
with schedule being successfully activated. Changed various events during
week and all changes were acknowledged and confirmed. Also sent Forecast
period and acknowledged with the proper status messages. All normal
operations tasks were verified, however, the anticipated viewing of the
TUT superimposed over the TSWs did not work. Further investigation is
needed and PASSDEV will be contacted. Operations will remain on
Release 13, possible testing again next week.