HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science
 
DAILY REPORT #5093
 
PERIOD COVERED: 5am May 10 - 5am May 11, 2010 (DOY 130/09:00z-131/09:00z)
 
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               9                9      
FGS REAcq               7                7      
OBAD with Maneuver 8                8      
 
SIGNIFICANT EVENTS: (None)
 
 
 
 
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.
 
ACS/WFC3 11882
 
CCD Hot Pixel Annealing
 
This program continues the monthly anneal that has taken place every
four weeks for the last three cycles. We now obtain WFC biases and darks
before and after the anneal in the same sequence as is done for the ACS
daily monitor (now done 4 times per week). So the anneal observation
supplements the monitor observation sets during the appropriate week.
Extended Pixel Edge Response (EPER) and First Pixel Response (FPR) data
will be obtained over a range of signal levels for the Wide Field
Channel (WFC). This program emulates the ACS pre-flight ground
calibration and post-launch SMOV testing (program 8948), so that results
from each epoch can be directly compared. The High Resolution Channel
(HRC) visits have been removed since it could not be repaired during
SM4.
 
This program also assesses the read noise, bias structure, and amplifier
cross-talk of ACS/WFC using the GAIN=1.4 A/D conversion setting. This
investigation serves as a precursor to a more comprehensive study of WFC
performance using GAIN=1.4.
 
COS/FUV 11895
 
FUV Detector Dark Monitor
 
Monitor the FUV detector dark rate by taking long science exposures
without illuminating 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.
 
COS/NUV 11537
 
COS-GTO: NUV Spectra of Bright Kuiper Belt Objects
 
NUV spectra of Kuiper Belt Objects (KBOs) other than Pluto have never
yet been obtained. We seek to use COS's sensitivity to determine NUV KBO
reflectance slopes and to compare/contrast different KBO spectra by
observing two of the brightest, 2005 FY9 and 2003 EL61, across the full
NUV band. These particular KBOs are known to have some distinctive
characteristics, prominently showing solid methane (2005 FY9) and water
ice (2003 EL61) absorption in near-IR spectra. 2003 EL61 is also unique
for its elongated shape; its rapid, 3.9-hour rotation period; and the
presence of two moons.
 
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.
 
COS/NUV/FUV 11598
 
How Galaxies Acquire their Gas: A Map of Multiphase Accretion and
Feedback in Gaseous Galaxy Halos
 
We propose to address two of the biggest open questions in galaxy
formation - how galaxies acquire their gas and how they return it to the
IGM - with a concentrated COS survey of diffuse multiphase gas in the
halos of SDSS galaxies at z = 0.15 - 0.35. Our chief science goal is to
establish a basic set of observational facts about the physical state,
metallicity, and kinematics of halo gas, including the sky covering
fraction of hot and cold material, the metallicity of infall and
outflow, and correlations with galaxy stellar mass, type, and color -
all as a function of impact parameter from 10 - 150 kpc. Theory suggests
that the bimodality of galaxy colors, the shape of the luminosity
function, and the mass-metallicity relation are all influenced at a
fundamental level by accretion and feedback, yet these gas processes are
poorly understood and cannot be predicted robustly from first
principles. We lack even a basic observational assessment of the
multiphase gaseous content of galaxy halos on 100 kpc scales, and we do
not know how these processes vary with galaxy properties. This ignorance
is presently one of the key impediments to understanding galaxy
formation in general. We propose to use the high-resolution gratings
G130M and G160M on the Cosmic Origins Spectrograph to obtain sensitive
column density measurements of a comprehensive suite of multiphase ions
in the spectra of 43 z < 1 QSOs lying behind 43 galaxies selected from
the Sloan Digital Sky Survey. In aggregate, these sightlines will
constitute a statistically sound map of the physical state and
metallicity of gaseous halos, and subsets of the data with cuts on
galaxy mass, color, and SFR will seek out predicted variations of gas
properties with galaxy properties. Our interpretation of these data will
be aided by state-of-the-art hydrodynamic simulations of accretion and
feedback, in turn providing information to refine and test such models.
We will also use Keck, MMT, and Magellan (as needed) to obtain optical
spectra of the QSOs to measure cold gas with Mg II, and optical spectra
of the galaxies to measure SFRs and to look for outflows. In addition to
our other science goals, these observations will help place the Milky
Way's population of multiphase, accreting High Velocity Clouds (HVCs)
into a global context by identifying analogous structures around other
galaxies. Our program is designed to make optimal use of the unique
capabilities of COS to address our science goals and also generate a
rich dataset of other absorption-line systems
 
COS/NUV/FUV 11837
 
A Co-ordinated Chandra, Suzaku, HST Campaign for NGC3227
 
We propose a 200ksec LETGS/HRC observation of NGC3227, a bright, nearby
AGN, coordinated with Suzaku monitoring and HST UV spectra. NGC3227
seems to have a distant, dusty, 'lukewarm' Warm Absorber (WA), AND a
smaller, high ionization, WA. For these WAs an LETGS grating spectrum
will determine: ionization parameter, NH, 'b'-parameter, metal ratios
and dust-specific features. The WA location will be known from Suzaku
monitoring; together Chandra and Suzaku observations determine the mass
loss rate. A joint HST/COS UV spectrum gives absolute metallicity and
velocity and covering factor. With the WAs well characterized, NGC3227
joins two other WAs to span M BH - L/L Edd space, allowing tests of
AGN-galaxy feedback models.
 
FGS 11704
 
The Ages of Globular Clusters and the Population II Distance Scale
 
Globular clusters are the oldest objects in the universe whose age can
be accurately determined. The dominant error in globular cluster age
determinations is the uncertain Population II distance scale. We propose
to use FGS 1R to obtain parallaxes with an accuracy of 0.2
milliarcsecond for 9 main sequence stars with [Fe/H] < -1.5. This will
determine the absolute magnitude of these stars with accuracies of 0.04
to 0.06mag. This data will be used to determine the distance to 24
metal-poor globular clusters using main sequence fitting. These
distances (with errors of 0.05 mag) will be used to determine the ages
of globular clusters using the luminosity of the subgiant branch as an
age indicator. This will yield absolute ages with an accuracy of 5%,
about a factor of two improvement over current estimates. Coupled with
existing parallaxes for more metal-rich stars, we will be able to
accurately determine the age for globular clusters over a wide range of
metallicities in order to study the early formation history of the Milky
Way and provide an independent estimate of the age of the universe.
 
The Hipparcos database contains only 1 star with [Fe/H] < -1.4 and an
absolute magnitude error less than 0.18 mag which is suitable for use in
main sequence fitting. Previous attempts at main sequence fitting to
metal-poor globular clusters have had to rely on theoretical
calibrations of the color of the main sequence. Our HST parallax program
will remove this source of possible systematic error and yield distances
to metal-poor globular clusters which are significantly more accurate
than possible with the current parallax data. The HST parallax data will
have errors which are 10 times smaller than the current parallax data.
Using the HST parallaxes, we will obtain main sequence fitting distances
to 11 globular clusters which contain over 500 RR Lyrae stars. This will
allow us to calibrate the absolute magnitude of RR Lyrae stars, a
commonly used Population II distance indicator.
 
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/CC 11654
 
UV Studies of a Core Collapse Supernova
 
Observations of the UV spectrum of core collapse SNe hold unique
information about nucleosynthesis, the mass loss history, shock physics
and dust formation in the explosion on massive stars. This proposal aims
at a detailed study of a bright core collapse SN, discovered by any of
the many ongoing surveys, either a Type IIP, IIn or Ibc supernova. We
will address the role of circumstellar interaction and mass loss through
CNO lines in the UV, the nature of dust formation from UV line profiles
and use the UV continuum as a diagnostic of non-thermal emission from
the shock. The overall goal of our team is to achieve a better
understanding of these objects by combining HST data with complementary
ground-based observations. We have used HST to obtain UV spectra from
the explosion to the nebular phase. Over the past decade, we have
conducted studies of nearby SNe with HST, and we have published an
extensive series of papers. When Nature provides a bright candidate, HST
should be ready to respond.
 
STIS/CC 11845
 
CCD Dark Monitor Part 2
 
Monitor the darks for the STIS CCD.
 
STIS/CC 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.
 
STIS/MA1 11861
 
MAMA FUV Flats
 
This program will obtain FUV-MAMA observations of the STIS internal
Krypton lamp to construct an FUV flat applicable to all FUV modes.
 
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.
 
WFC3/IR 12051
 
Cross Calibration of NICMOS and WFC3 in the Low-Count-Rate Regime
 
NICMOS has played a key role in probing the deep near infrared regime
for a decade. It has been the only instrument available to observe faint
objects in the near infrared that are not observable from the ground.
However, the calibration of NICMOS has turned out to be difficult in the
low-count-rate regime. The NICMOS calibration team has extrapolated a
power-law to describe the apparent non-linearity in the NICMOS detectors
from measurements at ~50-5000 ADU/s to flux counts around 0.1-1 ADU/s.
Precise measurements of faint objects (such as SNe Ia at high redshift)
require us to reduce the uncertainties from this extrapolation. Here we
propose to determine the absolute zeropoint for faint objects by
cross-calibrating the WFC3 and NICMOS detectors in observations of early
type galaxies at redshifts z>1.
 
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 11595
 
Turning Out the Light: A WFC3 Program to Image z>2 Damped Lyman Alpha
Systems
 
We propose to directly image the star-forming regions of z>2 damped Lya
systems (DLAs) using the WFC3/UVIS camera on the Hubble Space Telescope.
In contrast to all previous attempts to detect the galaxies giving rise
to high redshift DLAs, we will use a novel technique that completely
removes the glare of the background quasar. Specifically, we will target
quasar sightlines with multiple DLAs and use the higher redshift DLA as
a ``blocking filter'' (via Lyman limit absorption) to eliminate all FUV
emission from the quasar. This will allow us to carry out a deep search
for FUV emission from the lower redshift DLA, shortward of the Lyman
limit of the higher redshift absorber. The unique filter set and high
spatial resolution afforded by WFC3/UVIS will then enable us to directly
image the lower redshift DLA and thus estimate its size, star- formation
rate and impact parameter from the QSO sightline. We propose to observe
a sample of 20 sightlines, selected primarily from the SDSS database,
requiring a total of 40 HST orbits. The observations will allow us to
determine the first FUV luminosity function of high redshift DLA
galaxies and to correlate the DLA galaxy properties with the ISM
characteristics inferred from standard absorption-line analysis to
significantly improve our understanding of the general DLA population.
 
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 11912
 
UVIS Internal Flats
 
This proposal will be used to assess the stability of the flat field
structure for the UVIS detector throughout the 15 months of Cycle 17.
The data will be used to generate on-orbit updates for the delta-flat
field reference files used in the WFC3 calibration pipeline, if
significant changes in the flat structure are seen.