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Daily Report #5028



 
 
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Old February 8th 10, 09:42 PM posted to sci.astro.hubble
Bassford, Lynn[_2_]
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Default Daily Report #5028

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5028

PERIOD COVERED: 5am February 5 - 5am February 8, 2010 (DOY 036/10:00z-039/10:00z)

OBSERVATIONS SCHEDULED

WFC3/UV/ACS/WFC 12050

20th Anniversary of HST Launch

The 20th anniversary of HST's launch on April 24, 2010 will be a
significant milestone both in the Hubble mission and in the history of
U.S. space astronomy. Already plans are in place for many activities
surrounding this anniversary that take advantage of the "teachable
moment" afforded by this event. A new, high-impact image from Hubble
is a necessary component of this mix. We are proposing here to meet
that need with new observations of a dramatic region of the Carina
Nebula only partially observed previously with Hubble. The release of
the large mosaic of the Carina Nebula for HST's 17th anniversary was
one of the largest Hubble images ever released (Fig. 1). It contains
numerous dramatic details including the pillar containing HH 901 (Fig.
2) which was itself released as a separate detail image. What is not
widely realized, however, is that the HST data in the Carina mosaic is
limited to H-alpha only. The oxygen (502 nm) and sulfur (673 nm)
images were obtained with the MOSAIC camera at CTIO. These low
resolution images were combined with the much higher resolution HST
data to produce the final color image composite. When the full mosaic
is viewed, the loss of resolution is an acceptable compromise.
However, when zooming in on details, the effect is noticeable. We have
selected the most dramatic portion to return to with WFC3 to obtain
HST resolution in a complete filter set. In order to highlight the new
capabilities of WFC3 as well as foreshadowing the capabilities of
JWST, we will obtain a full 3-color composite in the IR channel of
WFC3 in addition

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.

WFC3/IR/S/C 11929

IR Dark Current Monitor

Analyses of ground test data showed that dark current signals are more
reliably removed from science data using darks taken with the same
exposure sequences as the science data, than with a single dark
current image scaled by desired exposure time. Therefore, dark current
images must be collected using all sample sequences that will be used
in science observations. These observations will be used to monitor
changes in the dark current of the WFC3-IR channel on a day-to-day
basis, and to build calibration dark current ramps for each of the
sample sequences to be used by Gos in Cycle 17. For each sample
sequence/array size combination, a median ramp will be created and
delivered to the calibration database system (CDBS).

WFC3/IR 11913

IR Filter Wedge Check

The position of each IR filter will be checked to verify that the
filters meet the CEI (Contract End Item) specification for image
displacement. We will observe the cluster NGC 1859 with all full-frame
IR filters using a subarray (IRSUB512) without moving the telescope.
The relative displacement of the stars in each image will be measured
from one filter to the next.

WFC3/UVIS/IR 11909

UVIS Hot Pixel Anneal

The on-orbit radiation environment of WFC3 will continually generate
new hot pixels. This proposal performs the procedure required for
repairing those hot pixels in the UVIS CCDs. During an anneal, the
two-stage thermo-electric cooler (TEC) is turned off and the
four-stage TEC is used as a heater to bring the UVIS CCDs up to ~20
deg. C. As a result of the CCD warmup, a majority of the hot pixels
will be fixed; previous instruments such as WFPC2 and ACS have seen
repair rates of about 80%. Internal UVIS exposures are taken before
and after each anneal, to allow an assessment of the procedure's
effectiveness in WFC3, provide a check of bias, global dark current,
and hot pixel levels, as well as support hysteresis (bowtie)
monitoring and CDBS reference file generation. One IR dark is taken
after each anneal, to provide a check of the IR detector.

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.

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).

COS/NUV 11894

NUV Detector Dark Monitor

The purpose of this proposal is to measure the NUV detector dark rate
by taking long science exposures with no light on the detector. The
detector dark rate and spatial distribution of counts will be compared
to pre-launch and SMOV data in order to verify the nominal operation
of the detector. Variations of count rate as a function of orbital
position will be analyzed to find dependence of dark rate on proximity
to the SAA. Dependence of dark rate as function of time will also be
tracked.

WFC3/ACS/UVIS 11877

HST Cycle 17 and Post-SM4 Optical Monitor

This program is the Cycle 17 implementation of the HST Optical
Monitoring Program.

The 36 orbits comprising this proposal will utilize ACS (Wide Field
Channel) and WFC3 (UVIS Channel) to observe stellar cluster members in
parallel with multiple exposures over an orbit. Phase retrieval
performed on the PSF in each image will be used to measure primarily
focus, with the ability to explore apparent coma, and astigmatism
changes in WFC3.

The goals of this program are to: 1) monitor the overall OTA focal
length for the purposes of maintaining focus within science tolerances
2) gain experience with the relative effectiveness of phase retrieval
on WFC3/UVIS PSFs 3) determine focus offset between the imagers and
identify any SI-specific focus behavior and dependencies

If need is determined, future visits will be modified to interleave
WFC3/IR channel and STIS/CCD focii measurements.

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/CCD 11844

CCD Dark Monitor Part 1

The purpose of this proposal is to monitor the darks for the STIS CCD.

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/UVIS 11714

Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters

Planetary nebulae (PNe) in globular clusters (GCs) raise a number of
interesting issues related to stellar and galactic evolution. The
number of PNe known in Milky Way GCs, four, is surprisingly low if one
assumes that all stars pass through a PN stage. However, it is likely
that the remnants of stars now evolving in galactic GCs leave the AGB
so slowly that any ejected nebula dissipates long before the star
becomes hot enough to ionize it. Thus there should not be ANY PNe in
Milky Way GCs--but there are four! It has been suggested that these
Pne are the result of mergers of binary stars within GCs, i.e., that
they are descendants of blue stragglers. The frequency of occurrence
of PNe in external galaxies poses more questions, because it shows a
range of almost an order of magnitude.

I propose a SNAPshot survey aimed at discovering PNe in the GC systems
of Local Group galaxies outside the Milky Way. These clusters, some of
which may be much younger than their counterparts in our galaxy, might
contain many more PNe than those of our own galaxy. I will use the
standard technique of emission-line and continuum imaging, which
easily discloses PNe. This proposal continues a WFPC2 program started
in Cycle 16, but with the more powerful WFC3. As a by-product, the
survey will also produce color-magnitude diagrams for numerous
clusters for the first time, reaching down to the horizontal branch.

WFC3/UVIS/IR 11644

A Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into
the Formation of the Outer Solar System

The eight planets overwhelmingly dominate the solar system by mass,
but their small numbers, coupled with their stochastic pasts, make it
impossible to construct a unique formation history from the dynamical
or compositional characteristics of them alone. In contrast, the huge
numbers of small bodies scattered throughout and even beyond the
planets, while insignificant by mass, provide an almost unlimited
number of probes of the statistical conditions, history, and
interactions in the solar system. To date, attempts to understand the
formation and evolution of the Kuiper Belt have largely been dynamical
simulations where a hypothesized starting condition is evolved under
the gravitational influence of the early giant planets and an attempt
is made to reproduce the current observed populations. With little
compositional information known for the real Kuiper Belt, the test
particles in the simulation are free to have any formation location
and history as long as they end at the correct point. Allowing
compositional information to guide and constrain the formation,
thermal, and collisional histories of these objects would add an
entire new dimension to our understanding of the evolution of the
outer solar system. While ground based compositional studies have hit
their flux limits already with only a few objects sampled, we propose
to exploit the new capabilities of WFC3 to perform the first ever
large-scale dynamical-compositional study of Kuiper Belt Objects
(KBOs) and their progeny to study the chemical, dynamical, and
collisional history of the region of the giant planets. The
sensitivity of the WFC3 observations will allow us to go up to two
magnitudes deeper than our ground based studies, allowing us the
capability of optimally selecting a target list for a large survey
rather than simply taking the few objects that can be measured, as we
have had to do to date. We have carefully constructed a sample of 120
objects which provides both overall breadth, for a general
understanding of these objects, plus a large enough number of objects
in the individual dynamical subclass to allow detailed comparison
between and within these groups. These objects will likely define the
core Kuiper Belt compositional sample for years to come. While we have
many specific results anticipated to come from this survey, as with
any project where the field is rich, our current knowledge level is
low, and a new instrument suddenly appears which can exploit vastly
larger segments of the population, the potential for discovery -- both
anticipated and not -- is extraordinary.

STIS/CCD/MA1/MA2 11616

The Disks, Accretion, and Outflows (DAO) of T Tau Stars

Classical T Tauri stars undergo magnetospheric accretion, power
outflows, and possess the physical and chemical conditions in their
disks to give rise to planet formation. Existing high resolution FUV
spectra verify that this spectral region offers unique diagnostics of
these processes, which have the potential to significantly advance our
understanding of the interaction of a star and its accretion disk. To
date the limited results are intriguing, with dramatic differences in
kinematic structure in lines ranging from C IV to H2 among the few
stars that have been observed. We propose to use HST/COS to survey the
disks, outflows, and accretion (the DAO) of 26 CTTS and 6 WTTS in the
FUV at high spectral resolution. A survey of this size is essential to
establish how properties of accretion shocks, winds and disk
irradiation depend on disk accretion rate. Specifically, our goals are
to (1) measure the radiation from and understand the physical
properties of the gas very near the accretion shock as a function of
accretion rate using emission line profiles of hot lines (C IV, Si IV,
N V, and He II); (2) measure the opacity, velocity, and temperature at
the base of the outflow to constrain outflow models using wind
absorption features; and (3) characterize the radiation incident on
disks and protoplanetary atmospheres using H2 line and continuum
emission and reconstructed bright Ly-alpha line emission.

WFC3/ACS/UVIS/IR 11570

Narrowing in on the Hubble Constant and Dark Energy

A measurement of the Hubble constant to a precision of a few percent
would be a powerful aid to the investigation of the nature of dark
energy and a potent "end-to end" test of the present cosmological
model. In Cycle 15 we constructed a new streamlined distance ladder
utilizing high- quality type Ia supernova data and observations of
Cepheids with HST in the near-IR to minimize the dominant sources of
systematic uncertainty in past measurements of the Hubble constant and
reduce its total uncertainty to a little under 5%. Here we propose to
exploit this new route to reduce the remaining uncertainty by more
than 30%, translating into an equal reduction in the uncertainty of
the equation of state of dark energy. We propose three sets of
observations to reach this goal: a mosaic of NGC 4258 with WFC3 in
F160W to triple its sample of long period Cepheids, WFC3/F160W
observations of the 6 ideal SN Ia hosts to triple their samples of
Cepheids, and observations of NGC 5584 the host of a new SN Ia, SN
2007af, to discover and measure its Cepheids and begin expanding the
small set of SN Ia luminosity calibrations. These observations would
provide the bulk of a coordinated program aimed at making the
measurement of the Hubble constant one of the leading constraints on
dark energy.

WFC3/ACS/IR 11563

Galaxies at z~7-10 in the Reionization Epoch: Luminosity Functions to
0.2L* from Deep IR Imaging of the HUDF and HUDF05 Fields

The first generations of galaxies were assembled around redshifts
z~7-10+, just 500-800 Myr after recombination, in the heart of the
reionization of the universe. We know very little about galaxies in
this period. Despite great effort with HST and other telescopes, less
than ~15 galaxies have been reliably detected so far at z7,
contrasting with the ~1000 galaxies detected to date at z~6, just
200-400 Myr later, near the end of the reionization epoch. WFC3 IR can
dramatically change this situation, enabling derivation of the galaxy
luminosity function and its shape at z~7-8 to well below L*,
measurement of the UV luminosity density at z~7-8 and z~8-9, and
estimates of the contribution of galaxies to reionization at these
epochs, as well as characterization of their properties (sizes,
structure, colors). A quantitative leap in our understanding of early
galaxies, and the timescales of their buildup, requires a total sample
of ~100 galaxies at z~7-8 to ~29 AB mag. We can achieve this with 192
WFC3 IR orbits on three disjoint fields (minimizing cosmic variance):
the HUDF and the two nearby deep fields of the HUDF05. Our program
uses three WFC3 IR filters, and leverages over 600 orbits of existing
ACS data, to identify, with low contamination, a large sample of over
100 objects at z~7-8, a very useful sample of ~23 at z~8-9, and limits
at z~10. By careful placement of the WFC3 IR and parallel ACS
pointings, we also enhance the optical ACS imaging on the HUDF and a
HUDF05 field. We stress (1) the need to go deep, which is paramount to
define L*, the shape, and the slope alpha of the luminosity function
(LF) at these high redshifts; and (2) the far superior performance of
our strategy, compared with the use of strong lensing clusters, in
detecting significant samples of faint z~7-8 galaxies to derive their
luminosity function and UV ionizing flux. Our recent z~7.4 NICMOS
results show that wide-area IR surveys, even of GOODS-like depth,
simply do not reach faint enough at z~7-9 to meet the LF and UV flux
objectives. In the spirit of the HDF and the HUDF, we will waive any
proprietary period, and will also deliver the reduced data to STScI.
The proposed data will provide a Legacy resource of great value for a
wide range of archival science investigations of galaxies at redshifts
z~2-9. The data are likely to remain the deepest IR/optical images
until JWST is launched, and will provide sources for spectroscopic
followup by JWST, ALMA and EVLA.

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.

COS/NUV/FUV 11522

COS-GTO: Star Formation/Lyman-Alpha

A sample of 20 star-forming galaxies will be observed with COS G130M.
The galaxies were selected from the Kitt Peak International
Spectroscopic Survey (KISSR) data release and cover a broad range of
luminosity, oxygen abundance, and reddening. The goal of the program
is to characterize the Lyman-alpha properties and establish
correlations with fundamental galaxy properties. Each galaxy will be
observed for one orbit.

COS/NUV/FUV/WFC3/UVI 11520 S/IR

COS-GTO: QSO Absorbers, Galaxies and Large-Scale Structures in the
Local Universe

This is a program to probe the large scale structure of baryons in the
universe, including addressing questions of baryon fraction, physical
conditions and relationships between absorbers and large-scale
structures of galaxies. Besides these specific goals, this proposed
GTO program also probes a large enough total path length in Ly alpha
and OVI to add significantly to what STIS/FUSE has already observed.
Several Galactic High Velocity Cloud Complexes also are probed by
these sightlines, particularly the M Complex. The total path length of
this proposed program for Ly alpha large-scale structure surveys is
delta_z~5.5.

We have selected a variety of targets to address these questions,
under the following subcategories:

1. Target 8 bright BL Lac objects to search for low contrast Ly alpha
absorbers from the warm- hot interstellar medium (WHIM).

2. Ly alpha cloud sizes: The targets are a bright AGN pair which yield
tangential distance separations of 100--500 kpc at z=0.01--0.05, where
galaxy surveys are excellent. This pair has two filaments and two
voids in this distance range.

3. Probes of starburst outflows: The targets are bright AGN, = 100
kpc in projection out of the minor axis of nearby starburst galaxies.

4. A large galaxy's gaseous halo: Three probes of the kinematics and
metallicity of a single L* galaxy halo. These observations includes
G130M, G160M exposures at SNR~20 and G285M at 2850A and SNR~10 for
MgII. The 2L* galaxy, ESO 157-G049 (cz=1678 km/s), being probed by
these sightlines has an available H I 21cm map from ATCA, H alpha
imaging from CTIO and long- slit spectra from MSSSO.

5. Dwarf galaxy winds: These targets probe the kinematics and
metallicities of outflows from active and inactive (in terms of star
formation) dwarfs.

WFC3/ACS/IR 11142

Revealing the Physical Nature of Infrared Luminous Galaxies at
0.3z2.7 Using HST and Spitzer

We aim to determine physical properties of IR luminous galaxies at
0.3z2.7 by requesting coordinated HST/NIC2 and MIPS 70um
observations of a unique, 24um flux-limited sample with complete
Spitzer mid-IR spectroscopy. The 150 sources investigated in this
program have S(24um) 0.8mJy and their mid-IR spectra have already
provided the majority targets with spectroscopic redshifts
(0.3z2.7). The proposed 150~orbits of NIC2 and 66~hours of MIPS 70um
will provide the physical measurements of the light distribution at
the rest-frame ~8000A and better estimates of the bolometric
luminosity. Combining these parameters together with the rich suite of
spectral diagnostics from the mid-IR spectra, we will (1) measure how
common mergers are among LIRGs and ULIRGs at 0.3z2.7, and establish
if major mergers are the drivers of z1 ULIRGs, as in the local
Universe, (2) study the co-evolution of star formation and blackhole
accretion by investigating the relations between the fraction of
starburst/AGN measured from mid-IR spectra vs. HST morphologies,
L(bol) and z, and (3) obtain the current best estimates of the far-IR
emission, thus L(bol) for this sample, and establish if the relative
contribution of mid-to-far IR dust emission is correlated with
morphology (resolved vs. unresolved).

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)

HSTARS:

#12182 GSAcq(1,2,1) @038/17:33:41z and REAcq(1,2,1) @038/20:45:04z
failed to RGA Hold (Gyro Control) due to search radius limit exceeded
on FGS-2

Observations affected: WFC3 #191-192 & #195-197 Proposal #12050

#12183 REAcq(1,2,1) at 038/19:09:13z failed to RGA Hold (gyro control)
due to scan step limit exceeded on FGS-1.

Observations affected: WFC3 #193-194 Proposal #12050

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSAcq 21 20
FGS REAcq 24 22
OBAD with Maneuver 17 10

SIGNIFICANT EVENTS: (None)

 




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