HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5026
PERIOD
COVERED: 5am February 3 - 5am February 4, 2010 (DOY 034/10:00z-035/10:00z)
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.
NIC2/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.
STIS/CC/MA
11516
COS-GTO:
Cold ISM
With
the COS, we will be able to observe interstellar spectra in a new
regime,
translucent clouds, for atomic, ionic, and molecular lines and
bands,
and extinction curves. The COS will allow us to observe stars
with
total visual extinctions up to 10 magnitudes, and the grain size
indicator
Rv up to 4.5. In translucent clouds we expect to see the
transition
from neutral and ionized carbon to mostly C I, and then from
there,
we should expect to see carbon increasingly locked up in
molecular
form, as CO. Other species are expected to make similar
transitions,
so we should find detectable abundances of molecules such
as
H2O, OH, CS, CH2, SiO, and others; also, lower ionization fractions
of
the metallic elements - and higher depletions of those elements as
well.
Given that we expect to find higher depletions, we should see an
altered
grain size distribution, which may show up in the extinction
curves,
probably as lower far-UV extinction than in diffuse clouds.
Finally,
we will search for neutral PAHs in absorption, as diffuse bands
in
the UV, paralleling the optical DIBs (which are thought by some
scientists
to be formed by singly-ionized PAHs). In translucent clouds,
models
show that the PAHs will be neutral, not in cationic form.
STIS/CCD
11844
CCD
Dark Monitor Part 1
The
purpose of this proposal is to monitor the darks for the STIS CCD.
STIS/CCD
11846
CCD
Bias Monitor-Part 1
The
purpose of this proposal is to 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.
STIS/MA1/MA2
11857
STIS
Cycle 17 MAMA Dark Monitor
This
proposal monitors the behavior of the dark current in each of the
MAMA
detectors.
The
basic monitor takes two 1380s ACCUM darks each week with each
detector.
However, starting Oct 5, pairs are only included for weeks
that
the LRP has external MAMA observations planned. The weekly pairs of
exposures
for each detector are linked so that they are taken at
opposite
ends of the same SAA free interval. This pairing of exposures
will
make it easier to separate long and short term temporal variability
from
temperature dependent changes.
For
both detectors, additional blocks of exposures are taken once every
six
months. These are groups of five 1314s FUV-MAMA Time-Tag darks or
five
3x315s NUV ACCUM darks distributed over a single SAA-free interval.
This
will give more information on the brightness of the FUV MAMA dark
current
as a function of the amount of time that the HV has been on, and
for
the NUV MAMA will give a better measure of the short term
temperature
dependence.
WFC3/ACS/UVIS
11724
Direct
Age Determination of the Local Group dE Galaxies NGC 147 and NGC
185
The
origin of dwarf elliptical (dE) galaxies remains a mystery and the
dE
galaxies of the Local Group provide the best opportunity to study
this
galaxy class in detail. We propose to obtain ACS photometry of main
sequence
turnoff stars in the M31 dE satellites NGC 147 and NGC 185.
Because
these galaxies have little to no stars younger than 1 Gyr,
resolving
the main sequence turnoff is required to directly quantify
their
star formation histories. NGC 147 and NGC 185 are the only two dEs
for
which a clean measurement is feasible with the HST. This proposal
was
accepted in Cycle 15, but little data were taken before the failure
of
ACS. The main sequence turnoffs of NGC 147 and NGC 185 are expected
to
be at an apparent magnitude of V=29; we request F606W/F814W imaging
one
half magnitude fainter than this limit (three magnitudes fainter
than
the deepest previous dE observations). Quantifying the ratio of old
to
intermediate-age stars will allow us to discriminate between
competing
models of dE formation. On-going Keck/DEIMOS spectroscopy of
several
hundred red giant stars in each of these two dE galaxies,
coupled
with dynamical modeling and spectral synthesis, will complement
the
ACS measurement by providing information on chemical abundance
patterns,
dark matter content and internal dynamics. The proposed ACS
data
will be the first to directly quantify the onset and duration of
star
formation episodes in dE galaxies, and will thereby form the
cornerstone
in what promises to be the most comprehensive study of this
class
of galaxies.
WFC3/IR
11915
IR
Internal Flat Fields
This
program is the same as 11433 (SMOV) and depends on the completion
of
the IR initial alignment (Program 11425). This version contains three
instances
of 37 internal orbits: to be scheduled early, middle, and near
the
end of Cycle 17, in order to use the entire 110-orbit allocation.
In
this test, we will study the stability and structure of the IR
channel
flat field images through all filter elements in the WFC3-IR
channel.
Flats will be monitored, i.e. to capture any temporal trends in
the
flat fields and delta flats produced. High signal observations will
provide
a map of the pixel-to-pixel flat field structure, as well as
identify
the positions of any dust particles.
WFC3/IR
11926
IR
Zero Points
We
will measure and monitor the zeropoints through the IR filters using
observations
of the white dwarf standard stars, GD153, GD71 and GD191B2B
and
the solar analog standard star, P330E. Data will be taken monthly
during
Cycle 17. Observations of the star cluster, NGC 104, are made
twice
to check color transformations. We expect an accuracy of 2% in the
wide
filter zeropoints relative to the HST photometric system, and 5% in
the
medium- and narrow-band filters.
WFC3/UVIS
11594
A
WFC3 Grism Survey for Lyman Limit Absorption at z=2
We
propose to conduct a spectroscopic survey of Lyman limit absorbers at
redshifts
1.8 < z < 2.5, using WFC3 and the G280 grism. This proposal
intends
to complete an approved Cycle 15 SNAP program (10878), which was
cut
short due to the ACS failure. We have selected 64 quasars at 2.3 < z
<
2.6 from the Sloan Digital Sky Survey Spectroscopic Quasar Sample, for
which
no BAL signature is found at the QSO redshift and no strong metal
absorption
lines are present at z > 2.3 along the lines of sight. The
survey
has three main observational goals. First, we will determine the
redshift
frequency dn/dz of the LLS over the column density range 16.0 <
log(NHI)
< 20.3 cm^-2. Second, we will measure the column density
frequency
distribution f(N) for the partial Lyman limit systems (PLLS)
over
the column density range 16.0 < log(NHI) < 17.5 cm^-2. Third, we
will
identify those sightlines which could provide a measurement of the
primordial
D/H ratio. By carrying out this survey, we can also help
place
meaningful constraints on two key quantities of cosmological
relevance.
First, we will estimate the amount of metals in the LLS using
the
f(N), and ground based observations of metal line transitions.
Second,
by determining f(N) of the PLLS, we can constrain the amplitude
of
the ionizing UV background at z~2 to a greater precision. This survey
is
ideal for a snapshot observing program, because the on-object
integration
times are all well below 30 minutes, and follow-up
observations
from the ground require minimal telescope time due to the
QSO
sample being bright.
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).
WFC3/UVIS
11907
UVIS
Cycle 17 Contamination Monitor
The
UV throughput of WFC3 during Cycle 17 is monitored via weekly
standard
star observations in a subset of key filters covering 200-600nm
and
F606W, F814W as controls on the red end. The data will provide a
measure
of throughput levels as a function of time and wavelength,
allowing
for detection of the presence of possible contaminants.
WFC3/UVIS
11908
Cycle
17: UVIS Bowtie Monitor
Ground
testing revealed an intermittent hysteresis type effect in the
UVIS
detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially
found via an unexpected bowtie-shaped feature in flatfield
ratios,
subsequent lab tests on similar e2v devices have since shown
that
it is also present as simply an overall offset across the entire
CCD,
i.e., a QE offset without any discernable pattern. These lab tests
have
further revealed that overexposing the detector to count levels
several
times full well fills the traps and effectively neutralizes the
bowtie.
Each visit in this proposal acquires a set of three 3x3 binned
internal
flatfields: the first unsaturated image will be used to detect
any
bowtie, the second, highly exposed image will neutralize the bowtie
if
it is present, and the final image will allow for verification that
the
bowtie is gone.
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
10
10
FGS
REAcq
07
07
OBAD
with Maneuver 09
09
SIGNIFICANT
EVENTS: (None)