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Daily Rpt #4987



 
 
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Old December 8th 09, 08:28 PM posted to sci.astro.hubble
Bassford, Lynn[_2_]
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Default Daily Rpt #4987

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #4987

PERIOD COVERED: 5am December 7 - 5am December 8, 2009 (DOY 341/10:00z-342/10:00z)

OBSERVATIONS SCHEDULED

ACS/WFC3 11879

CCD Daily Monitor (Part 1)

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 352 orbits (22 weeks) from 31 August
2009 to 31 January 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.

S/C 12046

COS FUV DCE Memory Dump

Whenever the FUV detector high voltage is on, count rate and current
draw information is collected, monitored, and saved to DCE memory.
Every 10 msec the detector samples the currents from the HV power
supplies (HVIA, HVIB) and the AUX power supply (AUXI). The last 1000
samples are saved in memory, along with a histogram of the number of
occurrences of each current value.

In the case of a HV transient (known as a "crackle" on FUSE), where
one of these currents exceeds a preset threshold for a persistence
time, the HV will shut down, and the DCE memory will be dumped and
examined as part of the recovery procedure. However, if the current
exceeds the threshold for less than the persistence time (a
"mini-crackle" in FUSE parlance), there is no way to know without
dumping DCE memory. By dumping and examining the histograms regularly,
we will be able to monitor any changes in the rate of "mini-crackles"
and thus learn something about the state of the detector.

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/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/STIS/CCD 11653

SAINTS - Supernova 1987A INTensive Survey

SAINTS is a program to observe SN 1987A, the brightest supernova since
1604, as it matures into the youngest supernova remnant at age 21. HST
is the essential tool for resolving SN1987A's many physical
components. A violent encounter is underway between the fastest-moving
debris and the circumstellar ring: shocks excite "hotspots." Radio,
optical, infrared and X-ray fluxes have been rising rapidly: we have
organized Australia Telescope, HST, VLT, Spitzer, and Chandra
observations to understand the several emission mechanisms at work.
Photons from the shocked ring will excite previously invisible gas
outside the ring, revealing the true extent of the mass loss that
preceded the explosion of Sanduleak -69 202. This will help test ideas
for the progenitor of SN 1987A. The inner debris, excited by
radioactive isotopes from the explosion, is now resolved and seen to
be aspherical, providing direct evidence on the shape of the explosion
itself. Questions about SN 1987A remain unanswered. A rich and
unbroken data set from SAINTS will help answer these central questions
and will build an archive for the future to help answer questions we
have not yet thought to ask.

WFC3/IR 11208

The Co-Evolution of Spheroids and Black Holes in the Last Six Billion
Years

The masses of giant black holes are correlated with the luminosities,
masses, and velocity dispersions of the bulges of their host galaxies.
This empirical correlation of phenomena on widely different scales
(from pcs to kpcs) suggests that the formation and evolution of
galaxies and central black holes are closely linked. In Cycle 13, we
have started a campaign to map directly the co-evolution of spheroids
and black-holes by measuring in observationally favorable redshift
windows the empirical correlations connecting their properties. By
focusing on Seyfert 1s, where the nucleus and the stars contribute
comparable fractions of total light, black hole mass and bulge
dispersion are obtained from Keck spectroscopy. HST is required for
accurate measurement of the non- stellar AGN continuum, the morphology
of the galaxy, and the structural parameters of the bulge. The results
at z=0.36 indicate a surprisingly fast evolution of bulges in the past
4 Gyrs (significant at the 95%CL), in the sense that bulges were
significantly smaller for a given black hole mass. Also, the large
fraction of mergers and disturbed galaxies (4+2 out of 20) identifies
gas-rich mergers as the mechanisms responsible for bulge- growth.
Going to higher redshift - where evolutionary trends should be
stronger - is needed to confirm these tantalizing results. We propose
therefore to push our investigation to the next suitable redshift
window z=0.57 (lookback-time 6 Gyrs). Fifteen objects are the minimum
number required to map the evolution of the empirical correlations
between bulge properties and black-hole mass, and to achieve a
conclusive detection of evolution (99%CL).

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/UVIS 11583

The Star Formation Rate In Nearby Elliptical Galaxies

Small amounts of star formation in normal elliptical galaxies are
suggested by several results: some surprisingly young ages from
optical line-index dating; cooling X-ray gas; and mid-IR dust
emission. Previously, it was difficult to detect low levels of star
formation, but UV imaging with WFPC3 will permit us to conclusively
identify individual O/B stars in nearby normal ellipticals by their UV
colors and magnitudes. This technique is orders of magnitude more
sensitive than previous methods, allowing detections of star formation
to levels of 1E-4 Msolar/yr. Proof of concept is provided by a very
long UV ACS observation of M87 that revealed many O/B stars. We
propose observations of four normal ellipticals where recent star
formation is likely. This will yield their star formation rates and
the locations of such activity.

WFC3/UVIS 11716

In Search of the Lost Remnant of M31 RV: Shedding Light on the New
Class of Luminous Red Transients

M31 RV is a luminous red variable star that appeared in the bulge of
M31 in 1988. During its outburst, which lasted a few months, it was
one of the brightest stars in the Local Group. Unlike a classical
nova, it was extremely cool during the eruption, and it never became
optically thin or exposed a hot, blue source. There has been renewed
interest in M31 RV recently, because of its remarkable similarities to
V838 Mon, a luminous Galactic variable star that underwent a similar
rapid expansion to become a red supergiant, and which is currently
illuminating a spectacular light echo, extensively observed by HST.
The outburst mechanism for this new class of luminous transients
remains unknown, and is one of the major current challenges to our
understanding of stellar physics.

Bond and Siegel have examined WFPC2 frames of the site of M31 RV,
obtained fortuitously in 1999 as parallel observations during
spectroscopic studies of the nucleus of M31. The explosion site shows
only a pure old population of red giants, with no obvious remnant of
M31 RV. I propose now to obtain second-epoch images of the site, in
the same filters, to determine whether there is an object in the field
that has faded or varied, and if so what its brightness and color is.
This information may provide new constraints on proposed outburst
mechanisms, such as stellar mergers or collisions, and could lead to a
spectroscopic observation in a future HST cycle.

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 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/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.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

#12113 GSAcq(1,2,1) @341/11:21:25z and REAcq(1,2,1) @341/12:18:13z
failed to RGA control with Search Radius Limit exceeded on FGS 2

Observations affected: WFC3 #17-18, Proposal #11653

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSAcq 6 5
FGS REAcq 8 7
OBAD with Maneuver 6 6

SIGNIFICANT EVENTS: (None)

 




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