Daily Report #4590
Cooper, Joe
DAILY REPORT # 4590
PERIOD COVERED: UT April 15, 2008 (DOY 106)
OBSERVATIONS SCHEDULED
FGS 11210
The Architecture of Exoplanetary Systems
Are all planetary systems coplanar? Concordance cosmogony makes that
prediction. It is, however, a prediction of extrasolar planetary system
architecture as yet untested by direct observation for main sequence stars
other than the Sun. To provide such a test, we propose to carry out FGS
astrometric studies on four stars hosting seven companions. Our
understanding of the planet formation process will grow as we match not only
system architecture, but formed planet mass and true distance from the
primary with host star characteristics for a wide variety of host stars and
exoplanet masses. We propose that a series of FGS astrometric observations
with demonstrated 1 millisecond of arc per-observation precision can
establish the degree of coplanarity and component true masses for four
extrasolar systems: HD 202206 {brown dwarf+planet}; HD 128311
{planet+planet}, HD 160691 = mu Arae {planet+planet}, and HD 222404AB =
gamma Cephei {planet+star}. In each case the companion is identified as such
by assuming that the minimum mass is the actual mass. For the last target, a
known stellar binary system, the companion orbit is stable only if coplanar
with the AB binary orbit.
NIC1 11117
The Search for Atmospheric Water in the Transiting Planet HD189733b
We propose to use the NICMOS camera to search for transit NIR signatures of
atmospheric water in HD189733b. While water absorption bands exist in the
optical and IR, space-based NIR signatures are uniquely positioned to offer
the best chance at detection. Using narrow band photometric filters, we will
be able to detect absorption signatures while the planet is in primary
transit. A positive detection would be the first proof of water on an
extrasolar planet. Furthermore, it would provide invaluable planetary
information, constraining the entire chemistry. As a byproduct of the high
SNR required for our primary science goal, we will be able to improve on the
value of the planetary radius, a result independent of our primary science
objective. The accurate radius estimate, together with planet structure
models, will allow constraining the planet interior and its relationship
with formation models and stellar metallicity.
NIC1/NIC2/NIC3 8795
NICMOS Post-SAA calibration - CR Persistence Part 6
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.
NIC3 11120
A Paschen-Alpha Study of Massive Stars and the ISM in the Galactic
Center
The Galactic center (GC) is a unique site for a detailed study of a
multitude of complex astrophysical phenomena, which may be common to nuclear
regions of many galaxies. Observable at resolutions unapproachable in other
galaxies, the GC provides an unparalleled opportunity to improve our
understanding of the interrelationships of massive stars, young stellar
clusters, warm and hot ionized gases, molecular clouds, large scale magnetic
fields, and black holes. We propose the first large-scale hydrogen Paschen
alpha line survey of the GC using NICMOS on the Hubble Space Telescope. This
survey will lead to a high resolution and high sensitivity map of the
Paschen alpha line emission in addition to a map of foreground extinction,
made by comparing Paschen alpha to radio emission. This survey of the inner
75 pc of the Galaxy will provide an unprecedented and complete search for
sites of massive star formation. In particular, we will be able to (1)
uncover the distribution of young massive stars in this region, (2) locate
the surfaces of adjacent molecular clouds, (3) determine important physical
parameters of the ionized gas, (4) identify compact and ultra-compact HII
regions throughout the GC. When combined with existing Chandra and Spitzer
surveys as well as a wealth of other multi-wavelength observations, the
results will allow us to address such questions as where and how massive
stars form, how stellar clusters are disrupted, how massive stars shape and
heat the surrounding medium, and how various phases of this medium are
interspersed.
NIC3 11149
Characterizing the Stellar Populations in Lyman-Alpha Emitters and Lyman
Break Galaxies at 5.7<z<7 in the Subaru Deep Field
The epoch of reionization marks a major phase transition of the Universe,
during which the intergalactic space became transparent to UV photons.
Determining when this occurred and the physical processes involved
represents the latest frontier in observational cosmology. Over the last few
years, searches have intensified to identify the population of high-redshift
(z>6) galaxies that might be responsible for this process, but the progress
is hampered partly by the difficulty of obtaining physical information
(stellar mass, age, star formation rate/history) for individual sources.
This is because the number of z>6 galaxies that have both secure
spectroscopic redshifts and high-quality infrared photometry (especially
with Spitzer/IRAC) is still fairly small. Considering that only several
photometric points are available per source, and that many model SEDs are
highly degenerate, it is crucial to obtain as many observational constraints
as possible for each source to ensure the validity of SED modeling. To
better understand the physical properties of high-redshift galaxies, we
propose here to conduct HST/NICMOS (72 orbits) and Spitzer/IRAC (102 hours)
imaging of spectroscopically confirmed, bright (z<26 mag (AB)) Ly-alpha
emitters (LAEs) and Lyman-break galaxies (LBGs) at 5.7<z<7 selected from the
Subaru Deep Field. Spectroscopic redshifts remove one critical free
parameter from SED modeling while bright source magnitudes ensure
high-quality photometric data. By making accurate determinations of stellar
masses, ages, and star-formation histories, we will specifically address the
following major questions: (1) Do LAEs and LBGs represent physically
different galaxy populations at z>6 as suggested recently? (2) Is Ly-alpha
emission systematically suppressed at z>6 with respect to continuum
emission? (i.e., are we reaching the epoch of incomplete reionization?), and
(3) Do we see any sign of abnormally young stellar population in any of the
z>6 galaxies?
WFPC2 11122
Expanding PNe: Distances and Hydro Models
We propose to obtain repeat narrowband images of a sample of eighteen
planetary nebulae {PNe} which have HST/WFPC2 archival data spanning time
baselines of a decade. All of these targets have previous high
signal-to-noise WFPC2/PC observations and are sufficiently nearby to have
readily detectable expansion signatures after a few years. Our main
scientific objectives are {a} to determine precise distances to these PNe
based on their angular expansions, {b} to test detailed and highly
successful hydrodynamic models that predict nebular morphologies and
expansions for subsamples of round/elliptical and axisymmetric PNe, and {c}
to monitor the proper motions of nebular microstructures in an effort to
learn more about their physical nature and formation mechanisms. The
proposed observations will result in high-precision distances to a healthy
subsample of PNe, and from this their expansion ages, luminosities, CSPN
properties, and masses of their ionized cores. With good distances and our
hydro models, we will be able to determine fundamental parameters {such as
nebular and central star masses, luminosity, age}. The same images allow us
to monitor the changing overall ionization state and to search for the
surprisingly non-homologous growth patterns to bright elliptical PNe of the
same sort seen by Balick & Hajian {2004} in NGC 6543. Non-uniform growth is
a sure sign of active pressure imbalances within the nebula that require
careful hydro models to understand.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.)
HSTARS: (None)
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSacq 06 06
FGS REacq 08 08
OBAD with Maneuver 26 26
SIGNIFICANT EVENTS: (None)