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.

A surprising result has emerged from the ACS Virgo Cluster Survey
{ACSVCS}, a program to obtain ACS/WFC gz imaging for a large, unbiased
sample of 100 early-type galaxies in the Virgo Cluster. On subarcsecond
scales {i.e., <0.1"-1"}, the HST brightness profiles vary systematically
from the brightest giants {which have nearly constant surface brightness
cores} to the faintest dwarfs {which have compact stellar nuclei}.
Remarkably, the fraction of galaxy mass contributed by the nuclei in the
faint galaxies is identical to that contributed by supermassive black
holes in the bright galaxies {0.2%}. These findings strongly suggest
that a single mechanism is responsible for both types of Central Massive
Object: most likely internally or externally modulated gas inflows that
feed central black holes or lead to the formation of "nuclear star
clusters". Understanding the history of gas accretion, star formation
and chemical enrichment on subarcsecond scales has thus emerged as the
single most pressing question in the study of nearby galactic nuclei,
either active or quiescent. We propose an ambitious HST program {199
orbits} that constitutes the next, obvious step forward:
high-resolution, ultraviolet {WFPC2/F255W} and infrared {NIC1/F160W}
imaging for the complete ACSVCS sample. By capitalizing on HST's unique
ability to provide high-resolution images with a sharp and stable PSF at
UV and IR wavelengths, we will leverage the existing optical HST data to
obtain the most complete picture currently possible for the history of
star formation and chemical enrichment on these small scales. Equally
important, this program will lead to a significant improvement in the
measured structural parameters and density distributions for the stellar
nuclei and the underlying galaxies, and provide a sensitive measure of
"frosting" by young stars in the galaxy cores. By virtue of its superb
image quality and stable PSF, NICMOS is the sole instrument capable of
the IR observations proposed here. In the case of the WFPC2
observations, high-resolution UV imaging {< 0.1"} is a capability unique
to HST, yet one that could be lost at any any time.

Now that the spectrophotometric capabilities of the NICMOS grism have
been established, cycle 15 observations are needed to refine the
sensitivity estimates, to check for sensitivity loss with time, to
improve the accuracy of the linearity correction, to improve the
secondary flux standards by re-observation, and to expand the G206 data
set now that the sky subtraction technique has been shown to produce
useful fluxes for some of the fainter secondary standards. These faint
secondary IR standards will be a significant step towards establishing
flux standards for JWST, as well as for SNAP, Spitzer, and SOFIA. 1.Re-
observe the 3 primary WDs GD71, G191B2b, & GD153 twice each, once at the
beginning and once near the end of the 18 month cycle. To date, we have
only 2 observation of each star, while the corresponding STIS data set
for these primary standards ranges from 6 to 23 obs. No observations
exist for GD71 or GD153 with G206, so that the current G206 sensitivity
is defined solely by G191B2B. Purposes: Refine sensitivities, measure
sens losses. Orbits: 2 for each of 6 visits = 12 2. Re-observe WD1057 &
WD1657 plus another P041C lamp-on visit to improve the scatter in the
non-lin measurements per Fig. 8 of NIC ISR 2006-02. The WD stars require
2 orbits each, while the lamp-on test is done in one. The very faintest
and most crucial standard WD1657 has 2 good visits already, so to
substantially improve the S/N, two visits of two orbits are needed.
Include G206 for P041C in the lamp-off baseline part of that orbit.
Orbits: WD1057-2, WD1657-4, P041C-1 --> 7 3. Re-observe 9 secondary
standards to improve S/N of the faint ones and to include G206 for all
9. BD+17 {3 obs} is not repeated in this cycle. Four are bright enough
to do in one orbit: VB8, 2M0036+18, P330E, and P177D. Orbits:2*5+4=14
Grand Total orbits over 18 month cycle 15 is 12+6+14=32 {Roelof will
submit the P041C lamp-on visit in a separate program.}

We propose observations with HST/FGS to estimate the astrometric
elements {perturbation orbit semi-major axis and inclination} of
extra-solar planets orbiting six stars. These companions were originally
detected by radial velocity techniques. We have demonstrated that FGS
astrometry of even a short segment of reflex motion, when combined with
extensive radial velocity information, can yield useful inclination
information {McArthur et al. 2004}, allowing us to determine companion
masses. Extrasolar planet masses assist in two ongoing research
frontiers. First, they provide useful boundary conditions for models of
planetary formation and evolution of planetary systems. Second, knowing
that a star in fact has a plantary mass companion, increases the value
of that system to future extrasolar planet observation missions such as
SIM PlanetQuest, TPF, and GAIA.

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}.

We propose to take full advantage of the recently commissioned
coronagraphic polarimetry modes of ACS and NICMOS to obtain imaging
polarimetry of circumstellar debris disks that were imaged previously by
the HST coronagraphs, but without the polarizers. It is well established
that stars form in gas-rich protostellar disks, and that the planets of
our solar system formed from a circum-solar disk. However, the
connection between the circumstellar disks that we observe around other
stars and the processes of planet formation is still very uncertain.
Mid-IR spectral studies have suggested that disk grains are growing in
the environments of young stellar objects during the putative
planet-formation epoch. Furthermore, structures revealed in well
resolved images of circumstellar disks suggest gravitational influences
on the disks from co-orbital bodies of planetary mass. Unfortunately,
existing imaging data provides only rudimentary information abou the
disk grains and their environments. Our proposed observations, which can
be obtained only with HST, will enable us to quantitatively determine
the sizes of the grains and optical depths as functions of their
location within the disks {i.e., detailed tomography}. Armed with these
well-determine physical and geometrical systemic parameters, we will
develop a set of self- consistent models of disk structures to
investigate possible interactions between unseen planets and the disks
from which they formed. Our results will also calibrate models of the
thermal emission from these disks, that will in turn enable us to infer
the properties of other debris disks that cannot be spatially resolved
with current or planned instruments and telescopes.

We propose to obtain NIC3/F160W imaging of three new IRAC-selected
galaxy clusters at 1.3 < z < 1.5. In combination with deep ACS/F850LP
images being obtained in Cycle 14, the resulting precision photometry in
a rest ~U - R color will allow us to construct color- magnitude diagrams
which can be used to measure the slope and scatter in the red sequence
galaxies, thereby constraining the history of star formation in the
early-type galaxies. The number of morphologically-selected early-type
galaxies more luminous than L* will allow us to test the predictions of
the hierarchical merging scenario for galaxy formation in clusters at
the highest available redshifts in galaxy clusters.

Previous WFPC2 observations have led to the serendipitous discovery of
an extended, highly-collimated, ``pulsed" bipolar jet emanating from a
compact planetary nebula, He 2- 90. Subsequently, an average proper
motion of the knots in the jet was measured, which together with radial
velocities, enabled us to characterise the basic physical properties of
the jet. The knotty jet in He 2-90 resembles other prominent examples of
pulsed jets in young stellar objects or symbiotic stars, but is probably
by far the best example yet of a non-relativistic, symmetric, jet in a
``clean" astrophysical environment. The formation {acceleration and
collimation} of jets is not fully understood, specially in the case of
jets in dying stars. We now propose to re-image He 2-90 with WFPC2 and
exploit the factor 3.5 longer time baseline now available from the
first-epoch observations in September 1999, in order to measure the
proper motion of individual knots in the jet with unprecedented
accuracy. These data will enable us to characterise the ejection history
of the source, specially deviations from a constant period {latter is
related to the binary period of the system}, e.g., due to instabilities
in the accretion mechanism. We will also be able to test if the ejection
mechanism is symmetric: any deviation in the ejection history of the
knots in the opposing jet beams, will indicate a magnetic field
structure and/or the accretion disk which is not symmetric across the
equatorial plane. We will also carry out deep imaging with the ACS/WFC
camera in order to determine the shapes/sizes of a large number of
knots. The shapes/sizes of the knots, and changes with distance from the
source probe the strength of the magnetic field inside the jet. HRC
imaging of the central source and jet on sub-arcsecond scales will be
carried out to probe the magnetic field close to the jet source, and
deviations from linearity in the jet-beam which may result from
instabilities in the magnetic field. These data will allow us to
significantly improve our existing 2- dimensional MHD model of the
He2-90 jet, and/or provide impetus for new 3-dimensional models.

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.

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.