NASA Hubble Space Telescope Daily Report # 3378
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3378
PERIOD COVERED: DOY 156
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/MA1 9184
A Survey for Missing Baryons in Highly Ionized Intergalactic Gas at Low
Redshift.
The Space Telescope Imaging Spectrograph (CCD and MA1) was used to observe
six
additional low-z QSOs with the STIS FUV E140M echelle mode {7 km s^-1
resolution}. Combined with archival data, this will increase the sample
redshift
path by a factor of ~7 compared to the published data. With the echelle
data, we
will {1} measure the number of O VI absorbers per unit redshift {dN/dz} and
their minimum cosmological mass density with a limiting equivalent width of
W_Lambda ~50 mAngstrom , {2} examine whether the O VI absorption arises in
photoionized, collisionally ionized, or multiphase gas, and {3} study the
dependence of the O VI system properties on environment. In addition to
testing
this prediction regarding the location of the missing baryons, the data will
have applications to many other topics such as low-z LyAlpha absorbers and
the
physical properties and abundances of gas in the Milky Way halo.
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.
ACS 9400
ARE THERE YOUNG GALAXIES IN THE LOCAL UNIVERSE: THE AGE OF THE BLUE COMPACT
DWARF GALAXY I ZW 18
The question of whether there exists young galaxies in the local universe is
important for cosmology. Cold Dark matter models predict that low-mass
galaxies
could still be forming at the present epoch. In the hierarchical model of
galaxy
formation, large galaxies result from the merging of smaller structures.
These
primordial building-block galaxies are too faint and small to be studied at
high
redshifts, while we stand a much better chance of understanding them if we
can
find some local examples. One of the best candidates for being a young
nearby
galaxy forming stars for the first time at the present epoch, is the blue
compact dwarf {BCD} galaxy I Zw 18 because of its extremely low heavy
element
content {2% that of the Sun}. We propose to obtain deep $V$ and $I$ ACS
images
of I Zw 18. Our goal is to detect or put limits on the red giant branch
{RGB}
stellar population in this galaxy. If RGB stars are not detected, then we
can
set an upper limit for the age of I Zw 18 to be less than 1 Gyr. If they are
detected, I Zw 18 is not young, and the RGB tip can be used to derive its
distance and set limits on the metallicity of the pregalactic gas.
GO 9406
GD 552: The Oldest Cataclysmic Variable
A terrible puzzle has long afflicted our understanding of the evolution of
cataclysmic variables {CVs}. Angular momentum loss should grind the binaries
down to orbital periods near 1.3 hr in 2 — 4 Gyr, and then slowly drive
them
apart again. Most CVs should therefore have undergone “period bounce" long
ago,
and be evolving towards longer period, with secondaries << 0.1 M_odot.
However,
not a single post-bounce CV has been conclusively identified. Where are the
old
CVs hiding? They should be hard to find since they’re probably faint
intrinsically, and because their accretion rates may be too low to trigger
dwarf-nova eruptions. One, and only one, good candidate appears in the
Lowell
proper-motion lists. This is GD 552: noneruptive, possessing a light
secondary,
and probably the least luminous CV yet found {M_V >~ +12.5}. An accurate FGS
parallax will establish whether this object {clearly very nearby} signifies
a
large population of very old CVs. A 1200 — 10000 Angstrom spectrum would
likely
represent a pure steady-state low-dot M disk {the only one known}, and the
FUV
region would provide a measurement of T_ eff in a white dwarf long after
eruptive heating episodes have stopped. The UV observation obviously
requires
HST, and efforts to measure the parallax from the ground are thwarted by a
background star 0^ .7 distant.
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 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.
STIS 9507
STIS/UV snapshot survey of bright AGN
We propose a UV spectroscopic snapshot survey of bright AGN, quadrupling the
number of Seyferts UV spectra and adding dozens of new quasars, aimed at the
following goals: beginenumerate em Finding the relationship between the
intrinsic luminosity of the AGN and the maximum velocity {and width} of the
outflow emanating from it, and determining the frequency of outflows in
low-z
AGN as a function of luminosity. em Surveying IGM absorption line systems in
numerous new sight-lines. em Identifying promising targets for observations
with
the future highly sensitive Cosmic Origin Spectrograph. endenumerate A
35-minute
snapshot with exposures in either the G140L or G230L will yield spectra with
a
minimum S/N > 15 per resolution element at all wavelengths for all our
potential
targets. This will allow us to be sensitive to absorption lines to a
limiting
equivalent width of 0.3 Angstrom at the 3 Sigma level. In order to
facilitate
rapid observational followup, we waive the data proprietary period entirely.
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.
WFPC2 9710
POMS Test Proposal: WFII backup parallel archive proposal
This is a POMS test proposal designed to simulate scientific plans.
ACS 9714
Hubble Heritage Observations of the Sombrero Galaxy
The Hubble Heritage Team will observe the entire Sombrero Galaxy {M104, NGC
4594} with a 6-point ACS mosaic. A color composite image will be released
to the
public via the Heritage website and an STScI photo release.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.) None
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 06 06
FGS REacq 8 8
FHST Update 14 14
LOSS of LOCK
SIGNIFICANT EVENTS:
Battery 6 returned to FSW 6-battery configuration @ 156/18:01Z. SOC-1
Safing Test
successfully modified to represent 6-battery system. Preliminary Battery 6
capacity
is 65.8 Ampere hours. Battery 6 Capacity Test completed @ 156/18:24Z (OR
16980).
Successfully completed SM-4 IPA-1 Hazardous Command Test 156/10:45Z –
13:52Z using
SOC/MCCSIM/CCSPSS, CCS "B" String, and PRD S07200. The objective of this
test were
to verify the ground software including the CCS and the Mission Control
Center
Simulator (MCCSIM). All objectives were met and no issues were brought up.
Testing was conducted from the SMOR with the FOT commanding and HITT
controlling the test.
