HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5096
PERIOD
COVERED: 5am May 13 - 5am May 14, 2010 (DOY 133/09:00z-134/09:00z)
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
12276
- GSAcq(2,0,2) scheduled at 133/09:37:03z failed to RGA control due
to scan step limit exceeded on FGS 2.
Observations affected: Astrometry, Proposal ID#11704.
12278
- GSAcq(2,0,2) scheduled at 133/11:12:51z failed to RGA Hold (gyro
control) due to scan step limit exceeded on FGS-2.
Observations affected: Astrometry, Proposal ID#11704
12280
- Following successful REAcq(1,2,1), a Loss of Lock occurred while
guiding with FGS-1 and FGS-2 at 134/08:23:29z. The REAcq continued
guiding until Term EXP at 134/08:43:02z.
Observation possibly affected: WFC3 159 Prop#11595
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS
GSAcq
8
6
FGS
REAcq
7
7
OBAD
with Maneuver 7 7
LOSS
of LOCK
134/0823z
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
ACS/WFC
11995
CCD
Daily Monitor (Part 2)
This
program comprises basic tests for measuring the read noise and dark current of
the ACS WFC and
for
tracking the growth of hot pixels. The recorded frames are used to create bias
and dark
reference
images for science data reduction and calibration. This program will be
executed four days
per
week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To facilitate
scheduling, this program
is
split into three proposals. This proposal covers 320 orbits (20 weeks) from 1
February 2010 to 20
June
2010.
COS/NUV
11720
Detailed
analysis of carbon atmosphere white dwarfs
We
propose to obtain UV spectra for the newly discovered white dwarf stars with a
carbon-dominated
atmosphere.
Model calculations show that these stars emit most of their light in the UV
part of the
electromagnetic
spectrum and that an accurate determination of the flux in this region is
crucial
for
an accurate determination of the atmospheric parameters. It will also provide a
unique
opportunity
to test the atomic data and broadening theory in stellar conditions never met
before.
This
will play a primordial role in our path to understand the origin of these
objects as well to
obtain
a better understanding of the evolution of stars in general. The principal
objective we hope
to
achieve with these observations are 1) obtain accurate surface gravity/mass for
these stars, 2)
constrain/determine
the abundance of other elements (O, He, Mg, Ne etc.), especially oxygen, 3)
verify
the accuracy of the various theoretical atomic data used in the model
calculations, 4)
understand
the origin and evolution of carbon atmosphere white dwarfs, in particular
whether
progenitor
stars as massive as 10.5 solar masses can produce white dwarfs, rather than
supernovae.
We
propose to observe 5 objects chosen carefully to cover the range of observed
properties among
carbon
atmosphere white dwarfs (effective temperature, surface gravity, abundance of
hydrogen/helium
and
magnetic field).
FGS
11704
The
Ages of Globular Clusters and the Population II Distance Scale
Globular
clusters are the oldest objects in the universe whose age can be accurately
determined. The
dominant
error in globular cluster age determinations is the uncertain Population II
distance scale.
We
propose to use FGS 1r to obtain parallaxes with an accuracy of 0.2
milliarcsecond for 9 main
sequence
stars with [Fe/H] < -1.5. This will determine the absolute magnitude of
these stars with
accuracies
of 0.04 to 0.06mag. This data will be used to determine the distance to 24
metal-poor
globular
clusters using main sequence fitting. These distances (with errors of 0.05 mag)
will be
used
to determine the ages of globular clusters using the luminosity of the subgiant
branch as an
age
indicator. This will yield absolute ages with an accuracy 5%, about a factor of
two improvement
over
current estimates. Coupled with existing parallaxes for more metal-rich stars,
we will be able
to
accurately determine the age for globular clusters over a wide range of
metallicities in order to
study
the early formation history of the Milky Way and provide an independent
estimate of the age of
the
universe.
The
Hipparcos database contains only 1 star with [Fe/H] < -1.4 and an absolute
magnitude error less
than
0.18 mag which is suitable for use in main sequence fitting. Previous attempts
at main sequence
fitting
to metal-poor globular clusters have had to rely on theoretical calibrations of
the color of
the
main sequence. Our HST parallax program will remove this source of possible
systematic error and
yield
distances to metal-poor globular clusters which are significantly more accurate
than possible
with
the current parallax data. The HST parallax data will have errors which are 10
times smaller
than
the current parallax data. Using the HST parallaxes, we will obtain main
sequence fitting
distances
to 11 globular clusters which contain over 500 RR Lyrae stars. This will allow
us to
calibrate
the absolute magnitude of RR Lyrae stars, a commonly used Population II
distance
indicator.
STIS/CCD
11682
An
HST/STIS spectroscopic investigation: is Kelu-1 AB a brown dwarf - brown dwarf
binary?
We
propose to obtain resolved HST/STIS spectroscopy for the benchmark binary brown
dwarf Kelu-1 AB.
Dynamical
masses are being obtained by monitoring the orbital motion using ground-based
telescopes
with
adaptive optics. The main goal of this program is to study the Li I resonance
line at 670.8 nm
and
investigate if only one or even both components bear lithium. This observation
will be compared
to
model predictions of lithium depletion as a function of age and mass, and
including our model
independent
ground-based mass estimations, hence will provide an observational test to the
theory of
substellar
objects. Spin-offs will be the measurement of the strength of H-alpha emission,
an
indicator
of chromospheric activity in cool atmospheres, and comparing the shape of the
optical
continuum
with model spectra with different dust opacities. Thus our program will be an
important
step
towards the understanding of brown dwarf atmospheres and to establish precise
models for their
formation
and evolution.
STIS/CCD
11845
CCD
Dark Monitor Part 2
Monitor
the darks for the STIS CCD.
STIS/CCD
11847
CCD
Bias Monitor-Part 2
Monitor
the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1, and 1x1 at gain
= 4, to build
up
high-S/N superbiases and track the evolution of hot columns.
WFC3/IR
11696
Infrared
Survey of Star Formation Across Cosmic Time
We
propose to use the unique power of WFC3 slitless spectroscopy to measure the
evolution of cosmic
star
formation from the end of the reionization epoch at z>6 to the close of the
galaxy-building era
at
z~0.3.Pure parallel observations with the grisms have proven to be efficient for
identifying line
emission
from galaxies across a broad range of redshifts. The G102 grism on WFC3 was
designed to
extend
this capability to search for Ly-alpha emission from the first galaxies. Using
up to 250
orbits
of pure parallel WFC3 spectroscopy, we will observe about 40 deep (4-5 orbit)
fields with the
combination
of G102 and G141, and about 20 shallow (2-3 orbit) fields with G141 alone.
Our
primary science goals at the highest redshifts are: (1) Detect Lya in ~100
galaxies with z>5.6
and
measure the evolution of the Lya luminosity function, independent of of cosmic
variance; 2)
Determine
the connection between emission-line selected and continuum-break selected
galaxies at
these
high redshifts, and 3) Search for the proposed signature of neutral hydrogen
absorption at
re-ionization.
At intermediate redshifts we will (4) Detect more than 1000 galaxies in Halpha
at
0.5<z<1.8
to measure the evolution of the extinction-corrected star formation density
across the
peak
epoch of star formation. This is over an order-of-magnitude improvement in the
current
statistics,
from the NICMOS Parallel grism survey. (5) Trace ``cosmic downsizing" from
0.5<z<2.2;
and
(6) Estimate the evolution in reddening and metallicty in star-forming galaxies
and measure the
evolution
of the Seyfert population. For hundreds of spectra we will be able to measure
one or even
two
line pair ratios -- in particular, the Balmer decrement and [OII]/[OIII] are
sensitive to gas
reddening
and metallicity. As a bonus, the G102 grism offers the possiblity of detecting
Lya
emission
at z=7-8.8.
To
identify single-line Lya emitters, we will exploit the wide 0.8--1.9um
wavelength coverage of
the
combined G102+G141 spectra. All [OII] and [OIII] interlopers detected in G102
will be reliably
separated
from true LAEs by the detection of at least one strong line in the G141
spectrum, without
the
need for any ancillary data. We waive all proprietary rights to our data and
will make
high-level
data products available through the ST/ECF.
WFC3/IR
11700
Bright
Galaxies at z>7.5 with a WFC3 Pure Parallel Survey
The
epoch of reionization represents a special moment in the history of the
Universe as it is during
this
era that the first galaxies and star clusters are formed. Reionization also
profoundly affects
the
environment where subsequent generations of galaxies evolve. Our overarching
goal is to test the
hypothesis
that galaxies are responsible for reionizing neutral hydrogen. To do so we
propose to
carry
out a pure parallel WFC3 survey to constrain the bright end of the redshift
z>7.5 galaxy
luminosity
function on a total area of 176 arcmin^2 of sky. Extrapolating the evolution of
the
luminosity
function from z~6, we expect to detect about 20 Lyman Break Galaxies brighter
than M_* at
z~8
significantly improving the current sample of only a few galaxies known at
these redshifts.
Finding
significantly fewer objects than predicted on the basis of extrapolation from
z=6 would set
strong
limits to the brightness of M_*, highlighting a fast evolution of the
luminosity function
with
the possible implication that galaxies alone cannot reionize the Universe. Our
observations
will
find the best candidates for spectroscopic confirmation, that is bright
z>7.5 objects, which
would
be missed by small area deeper surveys. The random pointing nature of the
program is ideal to
beat
cosmic variance, especially severe for luminous massive galaxies, which are
strongly clustered.
In
fact our survey geometry of 38 independent fields will constrain the luminosity
function like a
contiguous
single field survey with two times more area at the same depth. Lyman Break
Galaxies at
z>7.5
down to m_AB=26.85 (5 sigma) in F125W will be selected as F098M dropouts, using
three to five
orbits
visits that include a total of four filters (F606W, F098M, F125W, F160W)
optimized to remove
low-redshift
interlopers and cool stars. Our data will be highly complementary to a deep
field
search
for high-z galaxies aimed at probing the faint end of the luminosity function,
allowing us to
disentangle
the degeneracy between faint end slope and M_* in a Schechter function fit of
the
luminosity
function. We waive proprietary rights for the data. In addition, we commit to
release the
coordinates
and properties of our z>7.5 candidates within one month from the acquisition
of each
field.
WFC3/IR
11712
Calibration
of Surface Brightness Fluctuations for WFC3/IR
We
aim to characterize galaxy surface brightness fluctuations (SBF), and calibrate
the SBF distance
method,
in the F110W and F160W filters of the Wide Field Camera 3 IR channel. Because
of the very
high
throughput of F110W and the good match of F160W to the standard H band, we
anticipate that both
of
these filters will be popular choices for galaxy observations with WFC3/IR. The
SBF signal is
typically
an order of magnitude brighter in the near-IR than in the optical, and the
characterisitics
(sensitivity, FOV, cosmetics) of the WFC3/IR channel will be enormously more
efficient
for SBF measurements than previously available near-IR cameras. As a result,
our proposed
SBF
calibration will allow accurate distance derivation whenever an early-type or
bulge-dominated
galaxy
is observed out to a distance of 150 Mpc or more (i.e., out to the Hubble flow)
in the
calibrated
passbands. For individual galaxy observations, an accurate distance is useful
for
establishing
absolute luminosities, black hole masses, linear sizes, etc. Eventually, once a
large
number
of galaxies have been observed across the sky with WFC3/IR, this SBF
calibration will enable
accurate
mapping of the total mass density distribution in the local universe using the
data
available
in the HST archive. The proposed observations will have additional important
scientific
value;
in particular, we highlight their usefulness for understanding the nature of
multimodal
globular
cluster color distributions in giant elliptical galaxies.
WFC3/UVI
11595
Turning
out the Light: A WFC3 Program to Image z>2 Damped Lyman Alpha Systems
We
propose to directly image the star-forming regions of z>2 damped Lya systems
(DLAs) using the
WFC3/UVIS
camera on the Hubble Space Telescope. In contrast to all previous attempts to
detect the
galaxies
giving rise to high redshift DLAs, we will use a novel technique that
completely removes
the
glare of the background quasar. Specifically, we will target quasar sightlines
with multiple
DLAs
and use the higher redshift DLA as a ``blocking filter'' (via Lyman limit
absorption) to
eliminate
all FUV emission from the quasar. This will allow us to carry out a deep search
for FUV
emission
from the lower redshift DLA, shortward of the Lyman limit of the higher
redshift absorber.
The
unique filter set and high spatial resolution afforded by WFC3/UVIS will then
enable us to
directly
image the lower redshift DLA and thus estimate its size, star-formation rate
and impact
parameter
from the QSO sightline. We propose to observe a sample of 20 sightlines,
selected
primarily
from the SDSS database, requiring a total of 40 HST orbits. The observations
will allow us
to
determine the first FUV luminosity function of high redshift DLA galaxies and
to correlate the
DLA
galaxy properties with the ISM characteristics inferred from standard
absorption-line analysis
to
significantly improve our understanding of the general DLA population.
WFC3/UVI
11605
Obtaining
the Missing Links in the Test of Very Low Mass Evolutionary Models with HST
We
are proposing for spatially resolved ACS+HRC observations of 11 very low mass
binaries spanning
late-M,
L and T spectral types in order to obtain precise effective temperature
measurements for
each
component. All of our targets are part of a program in which we are measuring
dynamical masses
of
very low-mass binaries to an unprecedented precision of 10% (or better).
However, without precise
temperature
measurements, the full scientific value of these mass measurements cannot be
realized.
Together,
mass and temperature measurements will allow us to distinguish between brown
dwarf
evolutionary
models that make different assumptions about the interior and atmospheric
structure of
these
ultra-cool objects. While dynamical masses can be obtained from the ground in
the near-IR,
obtaining
precise temperatures require access to optical data which, for these
sub-arcsecond
binaries,
can only be obtained from space with Hubble.
WFC3/UVI
11643
A
Timeline for Early-Type Galaxy Formation: Mapping the Evolution of Star
Formation, Globular
Clusters,
Dust, and Black Holes
While
considerable effort has been devoted to statistical studies of the origin of
the red sequence
of
galaxies, there has been relatively little direct exploration of galaxies
transforming from late
to
early types. Such galaxies are identified by their post-starburst spectra,
bulge-dominated,
tidally-disturbed
morphologies, and current lack of gas. We are constructing the first detailed
timeline
of their evolution onto the red sequence, pinpointing when star formation ends,
nuclear
activity
ceases, globular clusters form, and the bulk of the merging progenitors' dust
disappears.
Here
we propose to obtain HST and Chandra imaging of nine galaxies, whose wide range
of
post-starburst
ages we have precisely dated with a new UV-optical technique and for which we
were
awarded
Spitzer time. We will address 1) whether the black hole-bulge mass relation
arises from
nuclear
feedback, 2) whether the bimodality of globular cluster colors is due to young
clusters
produced
in galaxy mergers, and 3) what happens to the dust when late types merge to
form an early
type.
WFC3/UVI
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<BR>and
dark frames. A smaller set of 2Kx4K subarray biases are acquired at less
frequent
intervals<BR>throughout
the cycle to support subarray science observations. The internals from this
proposal,<BR>along
with those from the anneal procedure (11909), will be used to generate the
necessary
superbias<BR>and superdark reference files for the calibration pipeline
(CDBS).