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Daily Report #4946



 
 
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Old October 7th 09, 04:15 PM posted to sci.astro.hubble
Cooper, Joe
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Default Daily Report #4946

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #4946

PERIOD COVERED: 5am October 6 - 5am October 7, 2009 (DOY 279/09:00z-280/09:00z)

OBSERVATIONS SCHEDULED

COS/FUV 11592

Testing the Origin(s) of the Highly Ionized High-Velocity Clouds: A
Survey of Galactic Halo Stars at z3 kpc

Cosmological simulation predicts that highly ionized gas plays an
important role in the formation and evolution of galaxies and their
interplay with the intergalactic medium. The NASA HST and FUSE
missions have revealed high-velocity CIV and OVI absorption along
extragalactic sightlines through the Galactic halo. These highly
ionized high-velocity clouds (HVCs) could cover 85% of the sky and
have a detection rate higher than the HI HVCs. Two competing, equally
exciting, theories may explain the origin of these highly ionized
HVCs: 1) the "Galactic" theory, where the HVCs are the result of
feedback processes and trace the disk-halo mass exchange, perhaps
including the accretion of matter condensing from an extended corona;
2) the "Local Group" theory, where they are part of the local warm-hot
intergalactic medium, representing some of the missing baryonic matter
of the Universe. Only direct distance determinations can discriminate
between these models. Our group has found that some of these highly
ionized HVCs have a Galactic origin, based on STIS observations of one
star at z5.3 kpc. We propose an HST FUV spectral survey to search for
and characterize the high velocity NV, CIV, and SiIV interstellar
absorption toward 24 stars at much larger distances than any previous
searches (4d21 kpc, 3|z|13 kpc). COS will provide atomic to highly
ionized species (e.g., OI, CII, CIV, SiIV) that can be observed at
sufficient resolution (R~22, 000) to not only detect these highly
ionized HVCs but also to model their properties and understand their
physics and origins. This survey is only possible because of the high
sensitivity of COS in the FUV spectral range.

COS/FUV/ACS/WFC/WFC3/UV/ 11632 NUV The Gaseous Corona of M31

We propose to obtain ultraviolet spectroscopy of the halo of M31, to
probe for a hot corona on scales of 30-40 pc from the galaxy. We seek
to obtain absorption line spectra of O I, Mg II, Si II, C IV, and Si
IV toward bright QSOs located behind the galaxy. One of the sightlines
falls on the projection of Ibata's giant stream. All background
sources have been vetted with GALEX photometry and are therefore
bright enough for observation. If hot gas is detected with this
initial study, we will endeavor to use a grid of background sources to
map the structure and kinematics of this gas in detail. M31 is the
nearest major spiral galaxy for which such a study can be undertaken,
other than our own Milky Way. Recent studies find a substantial
population of HI high velocity clouds at distances form M31 of up to
50 kpc, and there is well documented evidence of disrupted satellites
and tidal streams. These observations will shed light on the hot
gaseous halo of M31, but also will help in interpreting QSO sightlines
at high redshift.

NIC 11413

NICMOS Mode-2 Coronagraphic Target Acquisition Test

NICMOS coronagraphy is extremely sensitive to small centering errors
which can result from imperfections in the target acquisition (TA)
process. During HST Cycle 7 the on-board (TA) process was augmented
which resulted in post-acquisition dispersions of target placements
w.r.t. the fiducial position in the occulting system with 1-sigma RSX
(a) dispersions of 0.08 mas (or ~ 1/10 pixel) between targets and (b)
repeatability of 0.04 mas for identically executed target acquisitions
of the same target. This levels of acquisition precision and accuracy
are required to enable high-contrast imaging near occulted targets of
which the system is capable. This proposal corresponds to SMOV
activity NIC-10.

NIC1 11205

The Effects of Multiplicity on the Evolution of Young Stellar Objects:
A NICMOS Imaging Study

We propose to use NICMOS to investigate the multiplicity of young
stellar objects (YSOs) in the Orion B molecular cloud. Previous
observations with the Spitzer Space Telescope have revealed a
remarkable star forming filament near the NGC 2068 reflection nebula.
The population of YSOs associated with the filament exhibit a
surprisingly wide range of circumstellar evolutionary states, from
deeply embedded protostars to T Tauri accretion disks. Many of the
circumstellar disks themselves show evidence for significant dust
evolution, including grain growth and settling and cleared inner
holes, apparently in spite of the very young age of these stars. We
will estimate the binary fraction of a representative sample of
objects in these various stages of evolution in order to test whether
companions may play a significant role in that evolution.

NIC1/NIC2/NIC3 11947

Extended Dark Monitoring

This program takes a series of darks to obtain darks (including
amplifier glow, dark current, and shading profiles) for all three
cameras in the read-out sequences used in Cycle 17. A set of 12 orbits
will be observed every two months for a total of 72 orbits for a 12
month Cycle 17. This is a continuation of Cycle 16 program 11330
scaled down by ~80%.

The first orbit (Visit A0) should be scheduled in the NICMOS SMOV
after the DC Transfer Test (11406) and at least 36h before the Filter
Wheel Test (11407). Data download using fast track.

The following 28 orbits (visit A1-N2) should be scheduled AFTER the
SMOV Proposal 11407 (Filter Wheel Test). This is done in order to
monitor the dark current following an adjustment of the NCS set-point.
These visits should be executed until the final temperature is reached
during SMOV.

NIC1/NIC2/NIC3 8795

NICMOS Post-SAA Calibration - CR Persistence Part 6

This is a new procedure proposed to alleviate the CR-persistence
problem of NICMOS. Dark frames will be obtained immediately upon
exiting the SAA contour 23, and every time a NICMOS exposure is
scheduled within 50 minutes of coming out of the SAA. The darks will
be obtained in parallel in all three NICMOS cameras. The post-SAA
darks will be non-standard reference files available to users with a
'Use After' date/time mark. The keyword 'UseAfter=date/time' will also
be added to the header of each post-SAA dark frame. The keyword must
be populated with the time, in addition to the date, because HST
crosses the SAA ~8 times per day, so each post-SAA dark will need to
have the appropriate time specified, for users to identify the ones
they need. Both the raw and processed images will be archived as
post-SAA darks. Generally we expect that all NICMOS
science/calibration observations started within 50 minutes of leaving
an SAA will need such MAPs to remove the CR persistence from the
science images. Each observation will need its own CRMAP, as different
SAA passages leave different imprints on the NICMOS detectors.

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/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 11849

STIS CCD Hot Pixel Annealing

This purpose of this activity is to repair radiation induced hot pixel
damage to the STIS CCD by warming the CCD to the ambient instrument
temperature and annealing radiation-damaged pixels.

Radiation damage creates hot pixels in the STIS CCD Detector. Many of
these hot pixels can be repaired by warming the CCD from its normal
operating temperature near -83 deg. C to the ambient instrument
temperature (~ +5 deg. C) for several hours. The number of hot pixels
repaired is a function of annealing temperature. The effectiveness of
the CCD hot pixel annealing process is assessed by measuring the dark
current behavior before and after annealing and by searching for any
window contamination effects.

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/UVI/IR 11557

The Nature of Low-Ionization BAL QSOs

The rare subclass of optically-selected QSOs known as low-ionization
broad absorption line (LoBAL) QSOs show signs of high-velocity gas
outflows and reddened continua indicative of dust obscuration. Recent
studies show that galaxies hosting LoBAL QSOs tend to be ultraluminous
infrared systems that are undergoing mergers, and that have dominant
young ( 100 Myr) stellar populations. Such studies support the idea
that LoBAL QSOs represent a short- lived phase early in the life of
QSOs, when powerful AGN-driven winds are blowing away the dust and gas
surrounding the QSO. If so, understanding LoBALs would be critical in
the study of phenomena regulating black hole and galaxy evolution,
such as AGN feedback and the early stages of nuclear accretion. These
results, however, come from very small samples that may have serious
selection biases. We are therefore taking a more aggressive approach
by conducting a systematic multiwavelength study of a volume limited
sample of LoBAL QSOs at 0.5 z 0.6 drawn from SDSS. We propose to
image their host galaxies in two bands using WFC3/UVIS and WFC3/IR to
study the morphologies for signs of recent tidal interactions and to
map their interaction and star forming histories. We will thus
determine whether LoBAL QSOs are truly exclusively found in young
merging systems that are likely to be in the early stages of nuclear
accretion.

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.

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 7 7
FGS REAcq 7 7
OBAD with Maneuver 5 5

SIGNIFICANT EVENTS: (None)


 




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