HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4306
PERIOD COVERED: UT February 23,24,25, 2007 (DOY
054,055,056)
OBSERVATIONS SCHEDULED
NIC1/NIC2/NIC3 8794
NICMOS Post-SAA calibration - CR Persistence Part 5
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.
WFPC2 11093
Hubble Heritage Observations of PNe with WFPC2
This is a proposal for observation of a set of PNe using a
common WFPC2
observation sequence.
WFPC2 11092
Hubble Heritage Observations of Arp 87
The Hubble Heritage team will use a single pointing of
WFPC2 to obtain
F450W, F555W, F656N, and F814W images of Arp 87 as part of
a public
release image.
NIC3 11080
Exploring the Scaling Laws of Star Formation
As a variety of surveys of the local and distant Universe
are
approaching a full census of galaxy populations, our
attention needs to
turn towards understanding and quantifying the physical
mechanisms that
trigger and regulate the large-scale star formation rates
{SFRs} in
galaxies.
NIC1 11061
NICMOS Imaging of Grism Spectrophotometric Standards
In this program we will take imaging observations with all
3 cameras
with a range of filters of a significant number of stars
that are part
of the spectroscopic standard star project. These stars
will form the
fainter reference star backbone for programs as JWST,
Sophia, and SNAP.
With this program we will: 1. Accurately calibrate
relative brightness
of standard stars, which can be done more accurately with
photometry
than with spectroscopy. This has been proven to be vary
valuable to
straighten out the problems in the spectroscopic data
reduction and
calibrations so far. 2. Increase the number of stars over
a large
magnitude range to provide a more accurate cross check of
our count rate
dependent non-linearity correction 3. Include stars with
radically
different {very red} spectra to investigate whether the
filter curves as
measured before flight are still valid by comparing the
throughput
estimates from these stars to those used for the standard
calibration.
4. Repeat a few standard star observations from cycle 7
and post-NCS
installation SMOV, to increase the accuracy in the change
in sensitivity
measurement with just a few observations thanks to the
long baseline.
ACS/WFC 11052
Internal Flat Fields
The stability of the CCD P-flat fields will be monitored
using the
calibration lamps and a sub-sample of the filter set. High
signal
observations will be used to assess the stability of the
pixel-to-pixel
flat field structure and to monitor the position of the
dust motes.
WFPC2 11029
WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation
Anomaly
Monitor
Intflat observations will be taken to provide a linearity
check: the
linearity test consists of a series of intflats in F555W,
in each gain
and each shutter. A combination of intflats, visflats, and
earthflats
will be used to check the repeatability of filter wheel
motions.
{Intflat sequences tied to decons, visits 1-18 in prop
10363, have been
moved to the cycle 15 decon proposal xxxx for easier
scheduling.} Note:
long-exposure WFPC2 intflats must be scheduled during ACS
anneals to
prevent stray light from the WFPC2 lamps from
contaminating long ACS
external exposures.
ACS/WFC 10918
Reducing Systematic Errors on the Hubble Constant:
Metallicity
Calibration of the
Reducing the systematic errors on the Hubble constant is
still of
significance and of immediate importance to modern
cosmology. One of the
largest remaining uncertainties in the Cepheid-based
distance scale
{which itself is at the foundation of the HST Key Project
determination
of H_o} which can now be addressed directly by HST, is the
effect of
metallicity on the Cepheid Period-Luminosity relation.
Three chemically
distinct regions in M101 will be used to directly measure
and thereby
calibrate the change in zero point of the
range of metallicities that run from SMC-like, through
Solar, to
metallicities as high as the most metal-enriched galaxies
in the pure
Hubble flow. ACS for the first time offers the opportunity
to make a
precise calibration of this effect which currently
accounts for at least
a third of the total systematic uncertainty on Ho. The
calibration will
be made in the V and I bandpasses so as to be immediately
and directly
applicable to the entire HST Cepheid-based distance scale
sample, and
most especially to the highest-metallicity galaxies that
were hosts to
the Type Ia supernovae, which were then used to extend the
the distance
scale calibration out to cosmologically significant
distances.
WFPC2 10890
Morphologies of the Most Extreme High-Redshift
Mid-IR-Luminous Galaxies
The formative phase of the most massive galaxies may be
extremely
luminous, characterized by intense star- and
AGN-formation. Till now,
few such galaxies have been unambiguously identified at
high redshift,
restricting us to the study of low-redshift ultraluminous
infrared
galaxies as possible analogs. We have recently discovered
a sample of
objects which may indeed represent this early phase in
galaxy formation,
and are undertaking an extensive multiwavelength study of
this
population. These objects are bright at mid-IR wavelengths
{F[24um]>0.8mJy}, but deep ground based imaging
suggests extremely faint
{and in some cases extended} optical counterparts
{R~24-27}. Deep K-band
images show barely resolved galaxies. Mid-infrared
spectroscopy with
Spitzer/IRS reveals that they have redshifts z ~ 2-2.5,
suggesting
bolometric luminosities ~10^{13-14}Lsun! We propose to
obtain deep ACS
F814W and NIC2 F160W images of these sources and their
environs in order
to determine kpc-scale morphologies and surface photometry
for these
galaxies. The proposed observations will help us determine
whether these
extreme objects are merging systems, massive obscured
starbursts {with
obscuration on kpc scales!} or very reddened {locally
obscured} AGN
hosted by intrinsically low-luminosity galaxies.
WFPC2 10871
Observations of the Galilean Satellites in Support of the
New Horizons
Flyby
On February 28 2007 the New Horizons {NH} spacecraft will
fly by Jupiter
on its way to Pluto, and will conduct an extensive series
of
observations of the Jupiter system, including the Galilean
satellites.
We propose HST observations to support and complement the
New Horizons
observations in four ways: 1} Determine the distribution
and variability
of Io's plumes in the two weeks before NH closest
approach, to look for
correlations with Io- derived dust streams that may be
detected by New
Horizons, to understand the origin of the dust streams; 2}
Imaging of
SO2 and S2 gas absorption in Io's plumes in Jupiter
transit, which
cannot be done by NH; 3} Color imaging of Io's surface to
determine the
effects of the plumes and volcanos seen by New Horizons on
the surface-
New Horizons cannot image the sunlit surface in color due
to saturation;
4} Imaging of far-UV auroral emissions from the
atmospheres of Io,
Europa, and Ganymede in Jupiter eclipse, near-
simultaneously with
disk-integrated NH UV spectra, to locate the source of the
UV emissions
seen by NH and use the response of the satellite
atmospheres to the
eclipse to constrain production mechanisms.
ACS/SBC 10862
Comprehensive Auroral Imaging of Jupiter and Saturn during
the
International Heliophysical Year
A comprehensive set of observations of the auroral
emissions from
Jupiter and Saturn is proposed for the International
Heliophysical Year
in 2007, a unique period of especially concentrated
measurements of
space physics phenomena throughout the solar system. We
propose to
determine the physical relationship of the various auroral
processes at
Jupiter and Saturn with conditions in the solar wind at
each planet.
This can be accomplished with campaigns of observations,
with a sampling
interval not to exceed one day, covering at least one
solar rotation.
The solar wind plasma density approaching Jupiter will be
measured by
the New Horizons spacecraft, and a separate campaign near
opposition in
May 2007 will determine the effect of large-scale
variations in the
interplanetary magnetic field {IMF} on the Jovian aurora
by
extrapolation from near-Earth solar wind measurements. A
similar Saturn
campaign near opposition in Jan. 2007 will combine
extrapolated solar
wind data with measurements from a wide range of locations
within the
Saturn magnetosphere by Cassini. In the course of making
these
observations, it will be possible to fully map the auroral
footprints of
Io and the other satellites to determine both the local
magnetic field
geometry and the controlling factors in the
electromagnetic interaction
of each satellite with the corotating magnetic field and
plasma density.
Also in the course of making these observations, the
auroral emission
properties will be compared with the properties of the
near-IR
ionospheric emissions {from ground-based observations} and
non thermal
radio emissions, from ground-based observations for
Jupiter?s decametric
radiation and Cassini plasma wave measurements of the
Saturn Kilometric
Radiation {SKR}.
ACS/SBC 10810
The Gas Dissipation Timescale: Constraining Models of
Planet Formation
We propose to constrain planet-formation models by
searching for
molecular hydrogen emission around young {10-50 Myr}
solar-type stars
that have evidence for evolved dust disks. Planet
formation models show
that the presence of gas in disks is crucial to the
formation of BOTH
giant and terrestrial planets, influences dust dynamics,
and through
tidal interactions with giant planets leads to orbital
migration.
However, there is a lack of systematic information on the
presence and
lifetime of gas residing at planet-forming radii. We will
use a newly
identified broad continuum emission feature of molecular
hydrogen at
1600 Angstrom to search for residual gas within an orbital
radius of
5-10 AU around young stars that have evolved beyond the
optically thick
T Tauri phase. These observations will enable the most
sensitive probe
to date of remant gas in circumstellar disks, detecting
surfaces
densites of ~0.0001 g/cm^2, or less than 10^-5 of the
theoretical
"mininum mass" solar nebula from which our solar
system is thought to
have formed. Our observations are designed to be
synergistic with
ongoing searches for gas emission that is being performed
using the
Spitzer Space Telescope in that the proposed HST
observations are ~100
times more sensitive and will have 50 times higher angular
resolution.
These combined studies will provide the most comprehensive
view of
residual gas in proto-planetary disks and can set
important constraints
on models of planet formation.
NIC2 10808
Morphologies of spectroscopically-confirmed "red and
dead" galaxies at
z~2.5
Using a combination of wide-field near-infrared imaging
and very deep
follow-up near-infrared spectroscopy we have identified a
population of
massive "red and dead" galaxies at z~2.5. The
galaxies lack emission
lines and have strong Balmer/4000 Angstrom breaks,
demonstrating
directly that they have evolved stellar populations. These
objects are
very likely progenitors of massive ellipticals today and
may be
descendants of the first generation of galaxies. We
propose to image 10
of these objects with the NIC2 camera to determine their
morphologies.
The goals are to 1} determine whether they have the sizes
of present-day
early-types or are more compact, as predicted by models,
2} determine
the morphology, using visual classification and
quantitative methods,
and 3} constrain the evolution of the Kormendy relation
from z~2.5 to
the present. These observations will show whether the
oldest and most
massive galaxies at z~2.5 were already fully formed or
still in the
process of assembly.
NIC2, ACS/WFC 10802
SHOES-Supernovae, HO, for the Equation of State of Dark
energy
The present uncertainty in the value of the Hubble
constant {resulting
in an uncertainty in Omega_M} and the paucity of
redshifts exceeding 1 are now the leading obstacles to
determining the
nature of dark energy. We propose a single, integrated set
of
observations for Cycle 15 that will provide a 40%
improvement in
constraints on dark energy. This program will observe
known Cepheids in
six reliable hosts of
uncertainty in H_0 by a factor of two because of the
smaller dispersion
along the instability strip, the diminished extinction,
and the weaker
metallicity dependence in the infrared. In parallel with
ACS, at the
same time the NICMOS observations are underway, we will
discover and
follow a sample of
measurements, along with prior constraints from WMAP, will
provide a
great improvement in HST's ability to distinguish between
a static,
cosmological constant and dynamical dark energy. The
Hubble Space
Telescope is the only instrument in the world that can
make these IR
measurements of Cepheids beyond the Local Group, and it is
the only
telescope in the world that can be used to find and follow
supernovae at
z > 1. Our program exploits both of these unique
capabilities of HST to
learn more about one of the greatest mysteries in science.
ACS/WFC 10798
Dark Halos and Substructure from Arcs & Einstein Rings
The surface brightness distribution of extended
gravitationally lensed
arcs and Einstein rings contains super-resolved
information about the
lensed object, and, more excitingly, about the smooth and
clumpy mass
distribution of the lens galaxies. The source and lens
information can
non-parametrically be separated, resulting in a direct
"gravitational
image" of the inner mass-distribution of
cosmologically-distant galaxies
{Koopmans 2005; Koopmans et al. 2006 [astro-ph/0601628]}.
With this goal
in mind, we propose deep HST ACS-F555W/F814W and
NICMOS-F160W WFC
imaging of 20 new gravitational-lens systems with
spatially resolved
lensed sources, of the 35 new lens systems discovered by
the Sloan Lens
ACS Survey {Bolton et al. 2005} so far, 15 of which are
being imaged in
Cycle-14. Each system has been selected from the SDSS and
confirmed in
two time- efficient HST-ACS snapshot programs {cycle
13&14}.
High-fidelity multi-color HST images are required {not
delivered by the
420s snapshots} to isolate these lensed images {properly
cleaned,
dithered and extinction-corrected} from the lens galaxy
surface
brightness distribution, and apply our "gravitational
maging" technique.
Our sample of 35 early-type lens galaxies to date is by
far the largest,
still growing, and most uniformly selected. This minimizes
selection
biases and small-number statistics, compared to smaller,
often
serendipitously discovered, samples. Moreover, using the
WFC provides
information on the field around the lens, higher S/N and a
better
understood PSF, compared with the HRC, and one retains
high spatial
resolution through drizzling. The sample of galaxy mass
distributions -
determined through this method from the arcs and Einstein
ring HST
images - will be studied to: {i} measure the smooth mass
distribution of
the lens galaxies {dark and luminous mass are separated
using the HST
images and the stellar M/L values derived from a joint
stellar-dynamical
analysis of each system}; {ii} quantify statistically and
individually
the incidence of mass-substructure {with or without
obvious luminous
counter- parts such as dwarf galaxies}. Since dark-matter
substructure
could be more prevalent at higher redshift, both results
provide a
direct test of this prediction of the CDM hierarchical
structure-formation model.
NIC3 10792
Quasars at Redshift z=6 and Early Star Formation History
We propose to observe four high-redshift quasars {z=6} in
the NIR in
order to estimate relative Fe/Mg abundances and the
central black hole
mass. The results of this study will critically constrain
models of
joint quasar and galaxy formation, early star formation,
and the growth
of supermassive black holes. Different time scales and
yields for
alpha-elements {like O or Mg} and for iron result into an
iron
enrichment delay of ~0.3 to 0.6 Gyr. Hence, despite the
well-known
complexity of the FeII emission line spectrum, the ratio
iron/alpha -
element is a potentially useful cosmological clock. The
central black
hole mass will be estimated based on a recently revised
back hole mass -
luminosity relationship. The time delay of the iron
enrichment and the
time required to form a supermassive black hole {logM>8
Msol, tau
~0.5Gyr} as evidenced by quasar activity will be used to
date the
beginning of the first intense star formation, marking the
formation of
the first massive galaxies that host luminous quasars, and
to constrain
the epoch when supermassive black holes start to grow by
accretion.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
10713 - GSAcq(1,3,3) Failed to RGA hold @056/0110z
At
AOS, 01:23:45, noticed that GSAcq scheduled at 01:09:53 had failed.
The
only indication present was an ESB MSG a0a (FGS Fine Lock failed -
Timed
out waiting for fine lock)
OBAD
RSS was 8.12
The
REacq(1,3,3) scheduled at 02:43:01 also failed. Observed FGS 1
during
Reacq, FGS 1 never achieved fine lock. Maximum observed PMT
counts
was approximately 15.
OBAD
RSS wa 5.90 a-s
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS GSacq 21
20
FGS REacq 18
17
OBAD with Maneuver 68
68
SIGNIFICANT EVENTS: (None)