HST Daily Report # 3299
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3299
PERIOD COVERED: DOY 42
OBSERVATIONS SCHEDULED
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 9229
Orbits of Pre-Main Sequence Binaries
We propose to image one ACS field containing four spectroscopically
confirmed
Ly-alpha emitters at because there are still no such objects with an
accurately
measured mass. In cycle 5 we began to map the orbits of young multiple
star
systems in Taurus using FGS3. In cycle 8 we switched to the more capable
FGS1r.
We propose to continue to observe these binary and triple systems so that
we can
establish their visual orbits. In addition to our Transfer mode
observations, we
include Position mode observations of reference field stars so that the
position
of the multiple systems’ barycenter can be located, giving the relative
masses
of the components. In addition, the Position mode data will allow us to
determine accurate parallaxes for these systems, and hence the physical,
absolute masses of the young pre-main sequence stars along with absolute
magnitudes.
WFPC2/FGS 9332
WFPC2 Observations of Astrophysically Important Visual Binaries
This is a continuation of a Cycle 7-8-9 Long-Term project. The program
consists
of annual or biannual WFPC2 or FGS observations of three visual binary
stars
that will ultimately yield fundamental astrophysical results, once their
orbits
and masses are determined. Our targets are the following: {1} Procyon
{P=41
yr},
for which our first WFPC2 images yielded an extremely accurate angular
separation of the bright F star and its very faint white-dwarf companion.
Combined with ground-based astrometry of the bright star, our observation
significantly revised downward the derived masses, and brought Procyon A
into
excellent agreement with theoretical evolutionary tracks for the first
time. The
mass of Procyon B, however, implies a completely unexpected chemical
composition
for the white dwarf, and now poses a sharp evolutionary puzzle. With the
continued monitoring proposed here, we will obtain masses to an accuracy
of
better than 1%, providing a testbed for theories of Sun-like stars and
white
dwarfs. {2} G 107-70, a close double white dwarf {P=19 yr} that promises
to add
two accurate masses to the tiny handful of white-dwarf masses that are
directly
known from dynamical measurements. {3} Mu Cas {P=21 yr}, a famous
metal-deficient G dwarf for which accurate masses will lead to the stars’
helium
contents, with cosmological implications.
FGS 9347
FGS Astrometry of the Extrasolar Planet of Epsilon Eridani
We propose observations with HST/FGS in Position Mode to determine the
astrometric elements {perturbation orbit semimajor axis and inclination}
of the
candidate extra-solar planet around the K2 V star Epsilon Eridani that
has been
detected by Doppler spectroscopy. These observations will also permit us
to
determine the actual mass of the planet by providing the sin{i} factor
which can
not be determined with the radial velocity method. High precision radial
velocity {RV} measurements spanning the years 1980.8–2000.0 for the
nearby
{3.22 pc} star Epsilon Eri show convincing variations with a period of ~
7 yrs.
These data represent a combination of six independent data sets taken
with four
different telescopes. A least squares orbital solution using robust
estimation
yields orbital parameters of period, P = 6.9 yrs, velocity K- amplitude =
19
m/s, eccentricity e = 0.6, projected companion mass M_B sin{i} = 0.83
M_Jupiter.
An estimate of the inclination yields a perturbation semi-major axis,
Alpha =
0arcs0022, easily within the reach of HST/FGS astrometry.
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.
ACS 9411
Morphologies and faint neighbors of z=4.5 Lyman Alpha Emitting Galaxies
We propose to image one ACS field containing four spectroscopically
confirmed
Ly-alpha emitters at z=4.5 in restframe UV and a narrowband filter
containing
the Ly-alpha line. These observations will {A} Reveal the morphology of
the
four
spectroscopically confirmed sources. The high equivalent widths of the
Ly-alpha
line in these four galaxies in particular and this population in general
cannot
be explained without invoking one or more of: extreme youth of the
stellar
population, zero metallicity, energetic winds or type II quasars.
Comparison of
morphologies in the line and continuum would help favor or rule out some
of
these possibilties. This would also tell us whether the star-formation is
uniformly distributed or centrally concentrated or concentrated but in
many
clumps? Proximity of these galaxies {average projected physical
separation of
200 kpc, with one pair 30 kpc apart} also makes interactions likely. {B}
Extend
the luminosity function of Ly-alpha sources by 2.5 magnitudes due to
better
spatial resolution of HST and sensitivity of ACS. We will be able to
detect
sources with line flux of ~eq 2 * 10^-18 ergcm2s over 11.5 sq-arcmins {~
100
sources}. This complements the LALA {Large Area Lyman Alpha} survey which
covers
1/3 square-degree to a line sensitivity of ~eq 2 * 10^- 17. Thus we get a
picture of this patch of young universe in two ways: statistics of faint
galaxies and morphologies of relatively bright ones.
ACS 9472
A Snapshot Survey for Gravitational Lenses among z >= 4.0 Quasars
Over the last few years, the Sloan Digital Sky Survey has revolutionized
the
study of high-redshift quasars by discovering over 200 objects with
redshift
greater than 4.0, more than doubling the number known in this redshift
interval.
The sample includes eight of the ten highest redshift quasars known. We
propose
a snapshot imaging survey of a well-defined sample of 250 z > 4.0 quasars
in
order to find objects which are gravitationally lensed. Lensing models
including
magnification bias predict that at least 4% of quasars in a flux-limited
sample
at z > 4 will be multiply lensed. Therefore this survey should find of
order 10
lensed quasars at high redshift; only one gravitationally lensed quasar
is
currently known at z > 4. This survey will provide by far the best sample
to
date of high-redshift gravitational lenses. The observed fraction of
lenses can
put strong constraints on cosmological models, in particular on the
cosmological
constant Lambda. In addition, magnification bias can significantly bias
estimates of the luminosity function of quasars and the evolution
thereof; this
work will constrain how important an effect this is, and thereby give us
a
better understanding of the evolution of quasars and black holes at early
epochs, as well as constrain models for black hole formation.
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/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<z<1. We will determine the
morphological
k-correction, and the location of star formation within galaxies, using a
sample
that is likely to be nearly complete with multi-wavelength photometry and
spectroscopic redshifts. The results can be used to interpret
observations of
higher redshift galaxies by ACS.
ACS/WFPC2 9488
Cosmic Shear – with ACS Pure Parallel Observations
The ACS, with greater sensitivity and sky coverage, will extend our
ability to
measure the weak gravitational lensing of galaxy images caused by the
large
scale distribution of dark matter. We propose to use the ACS in pure
parallel
{non- proprietary} mode, following the guidelines of the ACS Default Pure
Parallel Program. Using the HST Medium Deep Survey WFPC2 database we have
measured cosmic shear at arc-min angular scales. The MDS image
parameters, in
particular the galaxy orientations and axis ratios, are such that any
residual
corrections due to errors in the PSF or jitter are much smaller than the
measured signal. This situation is in stark contrast with ground-based
observations. We have also developed a statistical analysis procedure to
derive
unbiased estimates of cosmic shear from a large number of fields, each of
which
has a very small number of galaxies. We have therefore set the stage for
measurements with the ACS at fainter apparent magnitudes and smaller, 10
arc-second scales corresponding to larger cosmological distances. We will
adapt
existing MDS WFPC2 maximum likelihood galaxy image analysis algorithms to
work
with the ACS. The analysis would also yield an online database similar to
that
in archive.stsci.edu/mds/
ACS/WFC 9575
Default {Archival} Pure Parallel Program.
The Advanced Camera for Surveys (WFC) was used to test ACS pure parallels
in
POMS.
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 9594
WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt2/3
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 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 9673
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 9706
STIS Pure Parallel Imaging Program: Cycle 10
This is the default archival pure parallel program for STIS during cycle
10.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies:
(The following are preliminary reports of potential non-nominal
performance
that will
be investigated.)
HSTAR 8927: During ZOE @ 042/21:22:04Z, GS Acquisition (2,0,2) failed.
At
AOS, in FN
format and FGS 1 was taking astrometry. The guide star
acquisition for this
observation was non-nominal, further analysis will
determine
if a repeat
observation is required.
COMPLETED OPS REQs:
NONE
OPS NOTES EXECUTED:
911-0 Limit Management During WFPC2 Decontamination (M001) (ULIMTECF) @
042/20:16z
911-0 Limit Management During WFPC2 Decontamination (M001) (ULIMTECN) @
043/06:47z
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 11 10 See Hstar # 8927
FGS REacq 3 3
FHST Update 23 23
LOSS of LOCK
SIGNIFICANT EVENTS: None
