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Daily Report #5197



 
 
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Old October 7th 10, 03:09 PM posted to sci.astro.hubble
Cooper, Joe
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Posts: 568
Default Daily Report #5197


HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5197

PERIOD COVERED: 8:00pm October 5 - 7:59pm October 6, 2010 (DOY 279/00:00z-279/23:59z)

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

12457 - GSAcq(2,3,3) at 279/15:10:26z resulted in fine lock back-up on
FGS2.

Observations possibly affected WFC3 39-40, Proposal ID#11905


COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

Scheduled Successful
FGS GSAcq 7 7
FGS REAcq 8 8
OBAD with Maneuver 4 4

SIGNIFICANT EVENTS: (None)

OBSERVATIONS SCHEDULED:

ACS/WFC 11996

CCD Daily Monitor (Part 3)

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 308 orbits (19.25 weeks) from 21 June
2010 to 1 November 2010.

ACS/WFC3 11734

The Hosts of High Redshift Gamma-Ray Bursts

Gamma-ray bursts are the most luminous explosive events known, acting
as beacons to the high redshift universe. Long duration GRBs have
their origin in the collapse of massive stars and thus select star
forming galaxies across a wide range of redshift. Due to their bright
afterglows we can study the details of GRB host galaxies via
absorption spectroscopy, providing redshifts, column densities and
metallicities for galaxies far too faint to be accessible directly
with current technology. We have already obtained deep ground based
observations for many hosts and here propose ACS/WFC3 and WFC3
observations of the fields of bursts at z3 which are undetected in
deep ground based images. These observations will study the hosts in
emission, providing luminosities and morphologies and will enable the
construction of a sample of high-z galaxies with more detailed
physical properties than has ever been possible before.

COS/NUV/FUV 12178

Spanning the Reionization History of IGM Helium: a Highly Efficient
Spectral Survey of the Far-UV-Brightest Quasars

The reionization of IGM helium likely occurred at redshifts of z=3 to
4. Detailed studies of HeII Ly-alpha absorption toward a handful of
quasars at 2.7z3.3 confirm the potential of such IGM probes, but the
small sample and redshift range limited confidence in cosmological
inferences. The requisite unobscured sightlines to high redshift are
extremely rare; but we've cross-correlated 10, 000 z2.8 SDSS DR7 (and
other) quasars with GALEX GR4/5, to identify 630 candidates
potentially useful for HST HeII studies. Our cycle 15-16 HST trials
confirm our approach, verifying twenty new HeII quasars at
unprecedented 40% efficiency. We propose to complete the first
efficient (80% with refinements) survey for HeII quasars, via
reconnaissance (~1 orbit) COS spectra of a highly select subset of 17
SDSS/GALEX quasars at 2.7z3.8. Along with past work, this program
will yield 3-4 of the brightest far-UV HeII sightlines within each of
10-12 redshift bins spanning 2.7z3.8, enabling a community sample
suitable for detailed spectral follow-up with HST. Herein, we will
also directly obtain quality UV spectral stacks within each redshift
bin to trace the reionization history of IGM helium; such spectral
stacks average over cosmic variance and individual object pathology.
Our high-yield HeII sightline sample and spectral stacks will enable
confident conclusions about the IGM baryon density, the spectrum and
evolution of the ionizing background, the evolution of HeII opacity,
and the epoch of helium reionization.

COS/NUV/FUV/WFC3/UV 12248

How Dwarf Galaxies Got That Way: Mapping Multiphase Gaseous Halos and
Galactic Winds Below L*

One of the most vexing problems in galaxy formation concerns how gas
accretion and feedback influence the evolution of galaxies. In high
mass galaxies, numerical simulations predict the initial fuel is
accreted through 'cold' streams, after which AGN suppress star
formation to leave galaxies red and gas-poor. In the shallow potential
wells that host dwarf galaxies, gas accretion can be very efficient,
and "superwinds" driven either by hot gas expelled by SNe or momentum
imparted by SNe and hot-star radiation are regarded as the likely
source(s) of feedback. However, major doubts persist about the physics
of gas accretion, and particularly about SN-driven feedback, including
their scalings with halo mass and their influence on the evolution of
the galaxies. While "superwinds" are visible in X-rays near the point
of their departure, they generally drop below detectable
surface-brightness limits at ~ 10 kpc. Cold clumps in winds can be
detected as blue-shifted absorption against the galaxy's own
starlight, but the radial extent of these winds are difficult to
constrain, leaving their energy, momentum, and ultimate fate
uncertain. Wind prescriptions in hydrodynamical simulations are
uncertain and at present are constrained only by indirect
observations, e.g. by their influence on the stellar masses of
galaxies and IGM metallicity. All these doubts lead to one conclusion:
we do not understand gas accretion and feedback because we generally
do not observe the infall and winds directly, in the extended gaseous
halos of galaxies, when it is happening. To do this effectively, we
must harness the power of absorption-line spectroscopy to measure the
density, temperature, metallicity, and kinematics of small quantities
of diffuse gas in galaxy halos. The most important physical
diagnostics lie in the FUV, so this is uniquely a problem for HST and
COS. We propose new COS G130M and G160M observations of 41 QSOs that
probe the gaseous halos of 44 SDSS dwarf galaxies well inside their
virial radii. Using sensitive absorption-line measurements of the
multiphase gas diagnostics Lya, CII/IV, Si II/III/IV, and other
species, supplemented by optical data from SDSS and Keck, we will map
the halos of galaxies with L = 0.02 - 0.3 L*, stellar masses M* =
10^(8-10) Msun, over impact parameter from 15 - 150 kpc. These
observations will directly constrain the content and kinematics of
accreting and outflowing material, provide a concrete target for
simulations to hit, and statistically test proposed galactic superwind
models. These observations will also inform the study of galaxies at
high z, where the shallow halo potentials that host dwarf galaxies
today were the norm. These observations are low-risk and routine for
COS, easily schedulable, and promise a major advance in our
understanding of how dwarf galaxies came to be.

FGS 11298

Calibrating Cosmological Chronometers: White Dwarf Masses

We propose to use HST/FGS1R to determine White Dwarf {WD} masses. The
unmatched resolving power of HST/FGS1R will be utilized to follow up
four selected WD binary pairs. This high precision obtained with
HST/FGS1R simply cannot be equaled by any ground based technique. This
proposed effort complements that done by CoI Nelan in which a sample
of WDs is being observed with HST/FGS1R. This proposal will
dramatically increase the number of WDs for which dynamical mass
measurements are possible, enabling a better calibration of the WD
mass-radius relation, cooling curves, initial to final mass relations,
and ultimately giving important clues to the star formation history of
our Galaxy and the age of its disk as well as in other galaxies. {This
project is part of Subasavage's PhD thesis work at Georgia State
University.}

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 12184

A SNAP Survey for Gravitational Lenses Among z~6 Quasars

We propose a SNAP imaging survey of a complete sample of 54 quasars at
5.7 z 6.4 using HST/WFC3-IR to quantify the prevalence of strongly
lensed quasars at z~6. Gravitational lensing magnification bias,
boosted by the observed steep luminosity function of high-redshift
quasars, strongly suggest that lenses should be common amongst the
highest-redshift quasars known. However, the highest redshift strongly
lensed quasar known is only at z=4.8; but among the 59 quasars known
at z5.9, only five have been imaged with HST. Our HST images will be
sensitive to the multiple images of lensed quasar, even at small
separations and large flux ratios. Based on the current best estimate
of the quasar luminosity function, we expect to discover 2-9 strongly
lensed quasars in our entire sample, or 1-4 for the nominal SNAP
completion rate of 40%. This program will likely discover the first
quasar lenses at z~6, enabling detailed follow-up observations to
constrain lensing models, to study quasar host galaxy properties and
to probe the small-scale structure of the IGM. The measurement of or
upper limit on the lensing fraction will strongly constrain the bright
end of the quasar luminosity function, leading to important
constraints on models of quasar evolution and allowing us to better
quantify the quasar contribution to the reionization photon budget.

WFC3/IR 12217

Spectroscopy of Faint T Dwarf Calibrators: Understanding the
Substellar Mass Function and the Coolest Brown Dwarfs

More than 100 methane brown dwarfs, or T dwarfs, have now been
discovered in the local field with 2MASS, SLOAN and UKIDSS, opening up
a new area of physics describing objects at 450-1400 K. However, very
few calibrator objects exist with well established ages and
metallicities. A very surprising result from the UKIDSS sample
(supported by 2MASS and SLOAN) is that the substellar mass function in
the local field appears to decline to lower masses, in marked contrast
to the rising initial mass function (IMF) observed in young clusters.
Given that such a difference between the present day IMF and the
Galactic time-averaged IMF is unlikely, it is very possible that the
apparently falling IMF is an artifact of serious errors in either T
model atmospheres or the evolutionary isochrones. We propose WFC3
spectroscopy of 4 faint T dwarf calibrators with well established ages
and metallicities in the Pleiades and Sigma Ori clusters, and 2 faint
field T dwarfs from UKIDSS for comparison. These spectra will
constitute vital calibration data for T dwarf atmospheres with a wide
range of surface gravities, which will be used to test and improve the
model atmospheres. They will also aid preparation for future
spectroscopy of the much larger numbers of field T dwarfs to soon be
found by VISTA and WISE. These new surveys will permit a more precise
measurement of the mass function and detection of even cooler objects.

WFC3/IR 12283

WFC3 Infrared Spectroscopic Parallel Survey (WISP): A Survey of Star
Formation Across Cosmic Time

We will use the unique power of WFC3 slitless spectroscopy to measure
cosmic star formation across its peak epoch. The broad, continuous,
spectral coverage of the G102 and G141 grisms provides the best
currently feasible measurement of the star formation rate continously
from 0.5z2.5, over which ground-based searches are severely limited.
Our Cycle 17 pure-parallel grism program has proven efficient for
identifying line emission from galaxies across this large fraction of
cosmic time. With less than two months of WFC3 observing completed,
our new measurments have more than doubled the sample of emission-line
galaxies that we found over the entire NICMOS Parallel Grism program.
We propose to extend this cost-effective WFC3 Survey by using 280
orbits of pure parallel grism spectroscopy in 50 deep (4-5 orbit)
fields with both G102 and G141, and 40 shallow (2-3 orbit) fields with
G141 alone. This will complete a sample of 2000-3000 emission line
galaxies in the "redshift desert" and search for serendipitous Lya
emitters at z5.5.

Our primary science goals a (1) Measure ratios of bright emission
lines ([OII], [OIII], Ha, and Hb) in a substantial fraction of these
galaxies, thereby estimating dust and metallicity evolution in a
sample of galaxies that is not biased by photometric selection. (2)
Derive an extinction-corrected Ha luminosity function, with a 20 times
larger sample than our previous NICMOS results. (3) Measure the
mass-metallicity relation at crucial intermediate redshifts, with the
support of our ongoing ground-based, follow-up, observing program (4)
Determine the spectroscopic close pair fraction in this sample, in
order to constrain hierarchal merging models (5) Uncover a new sample
of obscured AGN at these redshifts and, (6) Use the Balmer break
diagnostic to constrain the ages of continuum detected sources down to
H = 25.

As a bonus, these observations will be sensitive to Lya emission at
z5.5, taking advantage of continuous spectral coverage to observe
large volumes for luminous galaxies at the highest redshifts. Over
Cycles 17 and 18, we expect to detect 5-20 LAEs over redshifts
spanning 5.5 z 7.5. These observations will likely place the most
stringent constraint on the numbers of z6.5 Lya emitters until JWST.
We are waiving all proprietary rights to our data and will make
high-level data products available through the ST/ECF.

WFC3/IR 12286

Hubble Infrared Pure Parallel Imaging Extragalactic Survey (HIPPIES)

WFC3 has demonstrated its unprecedented power in probing the early
universe. Here we propose to continue our pure parallel program with
this instrument to search for LBGs at z~6--8. Our program, dubbed as
the Hubble Infrared Pure Parallel Imaging Extragalactic Survey
("HIPPIES"), will carry on the HST pure parallel legacy in the new
decade. We request 205 orbits in Cycle-18, which will spread over ~ 50
high Galactic latitude visits (|b|20deg) that last for 3 orbits and
longer, resulting a total survey area of ~230 square arcmin. Combining
the WFC3 pure parallel observations in Cycle-17, HIPPIES will
complement other existing and forthcoming WFC3 surveys, and will make
unique contributions to the study in the new redshift frontier because
of the randomness of the survey fields. To make full use of the
parallel opportunities, HIPPIES will also take ACS parallels to study
LBGs at z~5--6. Being a pure parallel program, HIPPIES will only make
very limited demand on the scarce HST resources, but will have
potentially large scientific returns. As in previous cycle, we waive
all proprietary data rights, and will make the enhanced data products
public in a timely manner.

(1) The WFC3 part of HIPPIES aims at the most luminous LBG population
at z~8 and z~7. As its survey fields are random and completely
uncorrelated, the number counts of the bright LBGs from HIPPIES will
be least affected by the "cosmic variance", and hence we will be able
to obtain the best constraint on the bright-end of the LBG luminosity
function at z~8 and 7. Comparing the result from HIPPIES to the
hydrodynamic simulations will test the input physics and provide
insight into the nature of the early galaxies. (2) The z~7--8
candidates from HIPPIES, most of which will be the brightest ones that
any surveys would be able to find, will have the best chance to be
spectroscopically confirmed at the current 8--10m telescopes. (3) The
ACS part of HIPPIES will produce a significant number of candidate
LBGs at z~5 and z~6 per ACS field. Combining with the existing,
suitable ACS fields in the HST archive, we will be able to utilize the
random nature of the survey to quantify the cosmic variance and to
measure the galaxy bias at z~5--6, and therefore the galaxy halo
masses at these redshifts. (4) We will also find a large number of
extremely red, old galaxies at intermediate redshifts, and the fine
spatial resolution offered by the WFC3 will enable us constrain their
formation history based on the study of their morphology, and hence
shed light on their connection to the very early galaxies in the
universe.

WFC3/UV 12019

After the Fall: Fading AGN in Post-starburst Galaxies

We propose joint Chandra and HST observations of an extraordinary
sample of 12 massive post-starburst galaxies at z=0.4-0.8 that are in
the short-lived evolution phase a few 100 Myr after the peak of
merger-driven star formation and AGN activity. We will use the data to
measure X-ray luminosities, black hole masses, and accretion rates;
and with the accurate "clocks" provided by post-starburst stellar
populations, we will directly test theoretical models that predict a
power-law decay in the AGN light curve. We will also test whether star
formation and black hole accretion shut down in lock-step, quantify
whether the black holes transition to radiatively inefficient
accretion states, and constrain the observational signatures of black
hole mergers.

WFC3/UV 12345

UVIS Long Darks Test

Darks during SMOV showed a systematically lower global dark rate as
well as lower scatter when compared to the Cycle 17 darks. Those two
sets of exposures differ in exposure time - 1800 sec during SMOV and
900 sec during Cycle 17. Hypothetically, the effect could be caused by
short-duration stray light, say ~500-sec in duration. During the
latter part of Cycle 17, operation of WFC3 was changed to additionally
block the light path to the detector with the CSM. This program
acquires a small number of darks at the longer SMOV exposure times
(1800 sec) in order to check whether the effect repeats in the new
operating mode.

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).


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