HST Daily Report #3322
DAILY REPORT # 3322
PERIOD COVERED: DOY 77
OBSERVATIONS SCHEDULED
FLIGHT OPERATIONS SUMMARY:
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 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.
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.
STIS/CCD 9378
Galaxy Dynamics at Very Large Radius using LyAlpha Absorption Lines
We propose to investigate the outer dynamics of the nearby spiral galaxy
NGC1398
at very large galactocentric radii by using the kinematical information from
Ly-alpha absorption lines in the spectra of 3 background UV-bright objects
{two
Seyferts 1 and one QSO}. It is a unique opportunity to have 3 UV-bright
objects
surrounding one single isolated spiral galaxy, and this will enable us to
measure its disk rotation up to radii several times greater than what is
possible in HI at 21cm, since the UV-bright objects lie at projected
distances
of ~ 80 to 270 kpc. At these large radii we expect to observe the turn down
from
flat rotation, and be able to determine the size of the dark matter halo and
hence measure the total mass and mass-to-light ratio of a spiral galaxy.
ACS 9463
Are OH/IR stars the youngest post-AGB stars? An ACS SNAPshot imaging survey
Essentially all well-characterized preplanetary nebulae {PPNs}– 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
propose an ACS/SNAPshot imaging survey of a large, morphologically unbiased
sample of these objects, selected using their IRAS 12-to-25micron colors.
Our
ground-based imaging study of OH/IR stars has revealed a few compact bipolar
objects, supporting our hypothesis. However since most objects remain
unresolved, HST observations are needed to determine how and when the
bipolar
geometry asserts itself. 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 PPNs, are common or rare phenomena.
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/NICMOS 9483
Origin and Evolution of IR Luminous Galaxies: Are z>=1 Dusty Starbursts and
z=0
ULIRGs the Same?
Interactions and mergers involving gas-rich galaxies are the main driving
mechanism behind the luminous IR galaxy phenomenon. However it is dangerous
to
extrapolate this model directly to high redshifts because massive spiral
progenitors may have been relatively uncommon at earlier epochs. Mergers and
interactions involving less massive but more gas-rich progenitors may have
occurred instead. We propose to test this hypothesis directly by imaging 12
FIR-selected, dusty starbursts at z~1 at sub-kpc resolution afforded by HST
in
the rest frame B and I {observed I and H} bands using ACS and NICMOS. While
studying higher redshift systems is clearly desirable, band-shifting and
surface
brightness dimming makes the investigations of tidal features and the nature
of
progenitors possible only out to z~ 1 {Hibbard & Vacca 1997}. From the
morphologies, surface brightnesses, and color distribution, we will
determine
the physical status of the starburst hosts, the history of tidal
interactions/mergers, and the nature of the progenitors. We will also test
for
the presence of hidden AGNs and for enhanced galaxy number density. Our 12
target galaxies form a complete sample of known ultraluminous and
hyperluminous
galaxies at 0.7<z<1.4 and represent the most distant and the best
statistical
set for investigating the nature and roles played by tidal interactions and
mergers in the dusty starburst phenomenon at high redshift.
NICMOS 9484
The NICMOS Parallel Observing Program
We propose to manage the default set of pure parallels with NICMOS. Our
experience with both our GO NICMOS parallel program and the public parallel
NICMOS programs in cycle 7 prepared us to make optimal use of the parallel
opportunities. The NICMOS G141 grism remains the most powerful survey tool
for
HAlpha emission-line galaxies at cosmologically interesting redshifts. It is
particularly well suited to addressing two key uncertainties regarding the
global history of star formation: the peak rate of star formation in the
relatively unexplored but critical 1<= z <= 2 epoch, and the amount of star
formation missing from UV continuum-based estimates due to high extinction.
Our
proposed deep G141 exposures will increase the sample of known HAlpha
emission-
line objects at z ~ 1.3 by roughly an order of magnitude. We will also
obtain a
mix of F110W and F160W images along random sight-lines to examine the space
density and morphologies of the reddest galaxies. The nature of the
extremely
red galaxies remains unclear and our program of imaging and grism
spectroscopy
provides unique information regarding both the incidence of obscured star
bursts
and the build up of stellar mass at intermediate redshifts. In addition to
carrying
out the parallel program we will populate a public database with calibrated
spectra
and images, and provide limited ground- based optical and near-IR data for
the
deepest parallel fields.
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/
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 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 9612
STIS CCD Hot Pixel Annealing Cycle 11
The effectiveness of the CCD hot pixel annealing process is assessed by
measuring the dark current behavior before and after annealing and by
searching
for any window contamination effects. In addition CTE performance is
examined by
looking for traps in a low signal level flat. Follows on from proposal 8906.
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
WFPC2 9676
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 9699
POMS Test Proposal: WFII backup parallel archive proposal
This is a POMS test proposal designed to simulate scientific plans.
STIS 9706
STIS Pure Parallel Imaging Program: Cycle 10
This is the default archival pure parallel program for STIS during cycle 10.
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:
0910-2 SI Console response to MCE Resets after FSW 4.8 is activated @
078/0302z
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 08 08
FGS REacq 09 09
FHST Update 11 11
LOSS of LOCK
SIGNIFICANT EVENTS: None
