HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #4967
PERIOD
COVERED: 5am November 5 - 5am November 6, 2009 (DOY 309/10:00z-310/10:00z)
OBSERVATIONS
SCHEDULED
COS/NUV/FUV/WFC3/UV/IR
11528
COS-GTO:
Studies of the HeII Reionization Epoch
Intergalactic
Ly-alpha opacity suggests that H I was reionized at z ~ 6,
while
He II reionization was delayed to z ~ 3. Both epochs are slightly
in
disagreement with recent (WMAP-3) inferences from the CMB optical
depth,
which suggest that IGM reionization occurred at z = 10.7 (+2.7,
-2.3)
(Spergel et al. 2007). However, these two methods are sensitive to
different
ranges of ionization (neutral fractions), which allows a
partially
ionized IGM between z = 6-10 produced by early stars and black
holes.
One of the major contributions of FUSE to cosmological studies
was
the detection of He II Ly-alpha (Gunn-Peterson) absorption in the
spectra
of two AGN at redshifts z = 2.72-2.89. The He II absorption is
quite
patchy between redshifts z = 2.6 and 3.2 probably because the IGM
is
clumpy and the reionization process is affected by source
fluctuations,
spectra, and radiative transfer through the IGM.
Observations
of the He II absorption can therefore be used as
diagnostics
of the ionizing sources and radiative transport over large
(30-50
Mpc) distances through the IGM. The ionizing radiation field
appears
to be softer (higher He II/H I) in the galaxy voids. These void
regions
may be ionized by local soft sources (dwarf starburst galaxies),
or
the QSO radiation may softened by escape from AGN cores and transport
through
denser regions in the cosmic web.With COS, we will observe the
brightest
He II target, HE2347-4342, a QSO with z_em = 2.885. Our goal
is
to obtain a G130M moderate-resolution (R = 20, 000) spectrum from
1145-1450A.
Because COS has far greater throughput than either STIS or
FUSE,
we will be able to resolve and characterize the He II absorption
lines.
The region shortward of the redshifted He II (Ly-alpha)
corresponds
to z = 2.77-2.92, where He II exhibits patchy transmission
and
absorption. The ratio of He II/H I (Ly-alpha line) opacities will
provide
information on the ionizing radiation field (and ionizing
sources)
at 1 and 4 ryd. We will perform similar He II studies on three
other
targets, HS1700+6416, PKS1935-692, and Q0302-003.
WFC3/IR
11548
Infrared
Imaging of Protostars in the Orion A Cloud: The Role of
Environment
in Star Formation
We
propose NICMOS and WFC3/IR observations of a sample of 252 protostars
identified
in the Orion A cloud with the Spitzer Space Telescope. These
observations
will image the scattered light escaping the protostellar
envelopes,
providing information on the shapes of outflow cavities, the
inclinations
of the protostars, and the overall morphologies of the
envelopes.
In addition, we ask for Spitzer time to obtain 55-95 micron
spectra
of 75 of the protostars. Combining these new data with existing
3.6
to 70 micron photometry and forthcoming 5-40 micron spectra measured
with
the Spitzer Space Telescope, we will determine the physical
properties
of the protostars such as envelope density, luminosity,
infall
rate, and outflow cavity opening angle. By examining how these
properties
vary with stellar density (i.e. clusters vs. groups vs.
isolation)
and the properties of the surrounding molecular cloud; we can
directly
measure how the surrounding environment influences protostellar
evolution,
and consequently, the formation of stars and planetary
systems.
Ultimately, this data will guide the development of a theory of
protostellar
evolution.
WFC3/IR
11202
The
Structure of Early-type Galaxies: 0.1-100 Effective Radii
The
structure, formation and evolution of early-type galaxies is still
largely
an open problem in cosmology: how does the Universe evolve from
large
linear scales dominated by dark matter to the highly non-linear
scales
of galaxies, where baryons and dark matter both play important,
interacting,
roles? To understand the complex physical processes
involved
in their formation scenario, and why they have the tight
scaling
relations that we observe today (e.g. the Fundamental Plane), it
is
critically important not only to understand their stellar structure,
but
also their dark-matter distribution from the smallest to the largest
scales.
Over the last three years the SLACS collaboration has developed
a
toolbox to tackle these issues in a unique and encompassing way by
combining
new non-parametric strong lensing techniques, stellar
dynamics,
and most recently weak gravitational lensing, with
high-quality
Hubble Space Telescope imaging and VLT/Keck spectroscopic
data
of early-type lens systems. This allows us to break degeneracies
that
are inherent to each of these techniques separately and probe the
mass
structure of early-type galaxies from 0.1 to 100 effective radii.
The
large dynamic range to which lensing is sensitive allows us both to
probe
the clumpy substructure of these galaxies, as well as their
low-density
outer haloes. These methods have convincingly been
demonstrated,
by our team, using smaller pilot-samples of SLACS lens
systems
with HST data. In this proposal, we request observing time with
WFC3
and NICMOS to observe 53 strong lens systems from SLACS, to obtain
complete
multi-color imaging for each system. This would bring the total
number
of SLACS lens systems to 87 with completed HST imaging and
effectively
doubles the known number of galaxy-scale strong lenses. The
deep
HST images enable us to fully exploit our new techniques, beat down
low-number
statistics, and probe the structure and evolution of early-
type
galaxies, not only with a uniform data-set an order of magnitude
larger
than what is available now, but also with a fully-coherent and
self-consistent
methodological approach!
WFC3/UVIS
11905
WFC3
UVIS CCD Daily Monitor
The
behavior of the WFC3 UVIS CCD will be monitored daily with a set of
full-frame,
four-amp bias and dark frames. A smaller set of 2Kx4K
subarray
biases are acquired at less frequent intervals throughout the
cycle
to support subarray science observations. The internals from this
proposal,
along with those from the anneal procedure (Proposal 11909),
will
be used to generate the necessary superbias and superdark reference
files
for the calibration pipeline (CDBS).
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
FOR
DAY 302
12067
- GSAcq(1,2,1) at 302/22:12:17 lost lock shortly after achieving
FL-DV on FGS2.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq
6
6
FGS
REAcq
7
7
OBAD
with Maneuver
8
8
SIGNIFICANT
EVENTS: (None)