HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT #5176

 

PERIOD COVERED: 5am September 7 - 5am September 8, 2010 (DOY 250/09:00z-251/09:00z)

 

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               04           04

FGS REAcq               11           11

OBAD with Maneuver 04           04

 

SIGNIFICANT EVENTS: (None)

 

 

OBSERVATIONS SCHEDULED:

 

ACS/WFC 12210

 

SLACS for the Masses: Extending Strong Lensing to Lower Masses and

Smaller Radii

 

Strong gravitational lensing provides the most accurate possible

measurement of mass in the central regions of early-type galaxies

(ETGs). We propose to continue the highly productive Sloan Lens ACS

(SLACS) Survey for strong gravitational lens galaxies by observing a

substantial fraction of 135 new ETG gravitational-lens candidates with

HST-ACS WFC F814W Snapshot imaging. The proposed target sample has been

selected from the seventh and final data release of the Sloan Digital

Sky Survey, and is designed to complement the distribution of previously

confirmed SLACS lenses in lens-galaxy mass and in the ratio of Einstein

radius to optical half-light radius. The observations we propose will

lead to a combined SLACS sample covering nearly two decades in mass,

with dense mapping of enclosed mass as a function of radius out to the

half-light radius and beyond. With this longer mass baseline, we will

extend our lensing and dynamical analysis of the mass structure and

scaling relations of ETGs to galaxies of significantly lower mass, and

directly test for a transition in structural and dark-matter content

trends at intermediate galaxy mass. The broader mass coverage will also

enable us to make a direct connection to the structure of well-studied

nearby ETGs as deduced from dynamical modeling of their line-of-sight

velocity distribution fields. Finally, the combined sample will allow a

more conclusive test of the current SLACS result that the intrinsic

scatter in ETG mass-density structure is not significantly correlated

with any other galaxy observables. The final SLACS sample at the

conclusion of this program will comprise approximately 130 lenses with

known foreground and background redshifts, and is likely to be the

largest confirmed sample of strong-lens galaxies for many years to come.

 

COS/FUV 11686

 

The Cosmological Impact of AGN Outflows: Measuring Absolute Abundances

and Kinetic Luminosities

 

AGN outflows are increasingly invoked as a major contributor to the

formation and evolution of supermassive black holes, their host

galaxies, the surrounding IGM, and cluster cooling flows. Our HST/COS

proposal will determine reliable absolute chemical abundances in six AGN

outflows, which influences several of the processes mentioned above. To

date there is only one such determination, done by our team on Mrk 279

using 16 HST/STIS orbits and 100 ksec of FUSE time. The advent of COS

and its high sensitivity allows us to choose among fainter objects at

redshifts high enough to preclude the need for FUSE. This will allow us

to determine the absolute abundances for six AGN (all fainter than Mrk

279) using only 40 HST COS orbits. This will put abundances studies in

AGN on a firm footing, an elusive goal for the past four decades. In

addition, prior FUSE observations of four of these targets indicate that

it is probable that the COS observations will detect troughs from

excited levels of C III. These will allow us to measure the distances of

the outflows and thereby determine their kinetic luminosity, a major

goal in AGN feedback research.
 11686( 7) - 25-Sep-2009 13:44:14 - [ 2]

 

We will use our state of the art column density extraction methods and

velocity-dependent photoionization models to determine the abundances

and kinetic luminosity. Previous AGN outflow projects suffered from the

constraints of deciding what science we could do using ONE of the

handful of bright targets that were observable. With COS we can choose

the best sample for our experiment. As an added

 

bonus, most of the spectral range of our targets has not been observed

previously, greatly increasing the discovery phase space.

 

COS/NUV/ACS/WFC/FUV 11658

 

Probing the Outer Regions of M31 with QSO Absorption Lines

 

We propose HST-COS spectroscopy of 10 quasars behind M31. Absorption

lines due to MgII, FeII, CIV, and a variety of other lines will be

searched for and measured. Six quasars lie between 1 and 4.2 Holmberg

radii near the major axis on the southwest side, where confusion with

Milky Way gas is minimized. Two lie even farther out on the southwest

side of the major axis. One lies within 1 Holmberg radius. Two of the 10

pass through M31's high velocity clouds seen in a detailed 21 cm

emission map. Exposure time estimates were based on SDSS magnitudes and

available GALEX magnitudes. Thus, using the most well-studied external

spiral galaxy in the sky, our observations will permit us to check,

better than ever before, the standard picture that quasar metal-line

absorption systems such as MgII and CIV arise in an extended gaseous

halo/disk of a galaxy well beyond its observable optical radius. The

observations will yield insights into the nature of the gas and its

connection to the very extended stellar components of M31 that have

recently been studied. Notably the observations have the potential of

extending M31's rotation curve to very large galactocentric distances,

thereby placing new constraints on M31's dark matter halo.

 

Finally, we also request that the coordinated parallel orbits be

allocated to this program so that we may image the resolved stellar

content of M31's halo and outer disk.

 

COS/NUV/FUV 11741

 

Probing Warm-Hot Intergalactic Gas at 0.5 < z < 1.3 with a Blind Survey

for O VI, Ne VIII, Mg X, and Si XII Absorption Systems

 

Currently we can only account for half of the baryons (or less) expected

to be found in the nearby universe based on D/H and CMB observations.

This "missing baryons problem" is one of the highest-priority challenges

in observational extragalatic astronomy. Cosmological simulations

suggest that the baryons are hidden in low-density, shock-heated

intergalactic gas in the log T = 5 - 7 range, but intensive UV and X-ray

surveys using O VI, O VII, and O VIII absorption lines have not yet

confirmed this prediction. We propose to use COS to carry out a

sensitive survey for Ne VIII and Mg X absorption in the spectra of nine

QSOs at z(QSO) > 0.89. For the three highest-redshift QSOs, we will also

search for Si XII. This survey will provide more robust constraints on

the quantity of baryons in warm-hot intergalactic gas at 0.5 < z < 1.3,

and the data will provide rich constraints on the metal enrichment,

physical conditions, and nature of a wide variety of QSO absorbers in

addition to the warm-hot systems. By comparing the results to other

surveys at lower redshifts (with STIS, FUSE, and from the COS GTO

programs), the project will also enable the first study of how these

absorbers evolve with redshift at z < 1. By combining the program with

follow-up galaxy redshift surveys, we will also push the study of

galaxy-absorber relationships to higher redshifts, with an emphasis on

the distribution of the WHIM with respect to the large-scale matter

distribution of the universe.

 

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.

 

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.

 

STIS/MA2 11862

 

MAMA NUV Flats

 

This program will obtain NUV-MAMA observations of the STIS internal

Deuterium lamp to construct an NUV flat applicable to all NUV modes.

 

WFC3/IR 11696

 

Infrared Survey of Star Formation Across Cosmic Time

 

We propose to use the unique power of WFC3 slitless spectroscopy to

measure the evolution of cosmic star formation from the end of the

reionization epoch at z>6 to the close of the galaxy-building era at

z~0.3.Pure parallel observations with the grisms have proven to be

efficient for identifying line emission from galaxies across a broad

range of redshifts. The G102 grism on WFC3 was designed to extend this

capability to search for Ly-alpha emission from the first galaxies.

Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will

observe about 40 deep (4-5 orbit) fields with the combination of G102

and G141, and about 20 shallow (2-3 orbit) fields with G141 alone.

 

Our primary science goals at the highest redshifts are: (1) Detect Lya

in ~100 galaxies with z>5.6 and measure the evolution of the Lya

luminosity function, independent of of cosmic variance; 2) Determine the

connection between emission line selected and continuum-break selected

galaxies at these high redshifts, and 3) Search for the proposed

signature of neutral hydrogen absorption at re-ionization. At

intermediate redshifts we will (4) Detect more than 1000 galaxies in

Halpha at 0.5<z<1.8 to measure the evolution of the extinction-corrected

star formation density across the peak epoch of star formation. This is

over an order-of-magnitude improvement in the current statistics, from

the NICMOS Parallel grism survey. (5) Trace ``cosmic downsizing" from

0.5<z<2.2; and (6) Estimate the evolution in reddening and metallicty in

star-forming galaxies and measure the evolution of the Seyfert

population. For hundreds of spectra we will be able to measure one or

even two line pair ratios -- in particular, the Balmer decrement and

[OII]/[OIII] are sensitive to gas reddening and metallicity. As a bonus,

the G102 grism offers the possibility of detecting Lya emission at

z=7-8.8.

 

To identify single-line Lya emitters, we will exploit the wide

0.8--1.9um wavelength coverage of the combined G102+G141 spectra. All

[OII] and [OIII] interlopers detected in G102 will be reliably separated

from true LAEs by the detection of at least one strong line in the G141

spectrum, without the need for any ancillary data. We waive all

proprietary rights to our data and will make high-level data products

available through the ST/ECF.

 

WFC3/IR/ACS/WFC 11663

 

Formation and Evolution of Massive Galaxies in the Richest Environments

at 1.5 < z < 2.0

 

We propose to image seven 1.5<z<2 clusters and groups from the IRAC

Shallow Cluster Survey with WFC3 and ACS in order to study the formation

and evolution of massive galaxies in the richest environments in the

Universe in this important redshift range. We will measure the evolution

of the sizes and morphologies of massive cluster galaxies, as a function

of redshift, richness, radius and local density. In combination with

allocated Keck spectroscopy, we will directly measure the dry merger

fraction in these clusters, as well as the evolution of Brightest

Cluster Galaxies (BCGs) over this redshift range where clear model

predictions can be confronted. Finally we will measure both the epoch of

formation of the stellar populations and the assembly history of that

stellar mass, the two key parameters in the modern galaxy formation

paradigm.

 

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/UV/IR 12234

 

Differentiation in the Kuiper belt: a Search for Silicates on Icy

Bodies.

 

We currently have a large on-going program (Go Program 11644, 120

orbits) to exploit the superb stability and photometric characteristics

of HST and the broad range in wavelength coverage of the WFC3 to make

broad-band vis/IR spectral observations of a large sample of Kuiper belt

objects. Though the survey is currently only ~50% complete, the quality

and unprecedented signal-to-noise of these observations has revealed the

existence of a previously undiscovered spectral variability not

explainable within our current understanding of these objects.

 

A possible explanation for this variability is that with this faint set

of Kuiper belt objects, we are beginning to see the difference between

larger differentiated objects and smaller non-differentiated objects.

Its seems that the small and likely undifferentiated objects are

exhibiting silicate features that affect our photometry - features not

exhibited by the icy mantles of larger icy bodies.

 

We propose a small add-on survey to dramatically increase the scientific

results of our large program. The proposed observations will use the

proven capabilities of WFC3 to make broad and narrow-band photometric

observations to detect spectral features in the 1.0-1.3 micron range of

a small subset of our sources. The 13 targets have been carefully

selected to cover the range of spectral variability detected in our

large program as well as sample the entire dynamical range and physical

sizes of these targets. These observations will allow the identification

of undifferentiated Kuiper belt objects by detection of their silicate

features. As a probe for differentiation, these observations could

constrain the natal locations of different Kuiper belt classes, a

constraint currently unavailable to formation models. This small set of

observations will allow the calibration of the spectral variability seen

in our large program, and drastically enhance the scientific output of

our full Cycle 17 sample.

 

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.