Daily # 4306

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 Cepheid PL Relation

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 Cepheid
PL relation over a 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 Type Ia supernovae at
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 Type Ia supernovae with NICMOS, reducing the
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 Type Ia supernovae at z 1. Together,
these 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 {logM8 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)