HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5181

PERIOD COVERED: 5am September 14 - 5am September 15, 2010 (DOY 257/09:00z-258/09:00z)

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:

18917-0 - Set STIS Event Flags 2 and 3 to inhibit further MAMA ops @ 257/18:59z

COMPLETED OPS NOTES: (None)

                     SCHEDULED SUCCESSFUL

FGS GSAcq               9            9                 

FGS REAcq               6             6 

OBAD with Maneuver 5             5 

SIGNIFICANT EVENTS:

Ops Request 18917-0 at approximately 257/19:00 UTC,

set the STIS event flags 2 and 3 in the NSSC-1 to

prevent MAMA Low Voltage from being enabled.

OBSERVATIONS SCHEDULED:

ACS/WFC 12209

A Strong Lensing Measurement of the Evolution of Mass Structure in Giant

Elliptical Galaxies

The structure and evolution of giant elliptical galaxies provide key

quantitative tests for the theory of hierarchical galaxy formation in a

cold dark matter dominated universe. Strong gravitational lensing

provides the only direct means for the measurement of individual

elliptical galaxy masses beyond the local universe, but there are

currently no large and homogeneous samples of strong lens galaxies at

significant cosmological look-back time. Hence, an accurate and

unambiguous measurement of the evolution of the mass-density structure

of elliptical galaxies has until now been impossible. Using

spectroscopic data from the recently initiated Baryon Oscillation

Spectroscopic Survey (BOSS) of luminous elliptical galaxies at redshifts

from approximately 0.4 to 0.7, we have identified a large sample of

high-probability strong gravitational lens candidates at significant

cosmological look-back time, based on the detection of emission-line

features from more distant galaxies along the same lines of sight as the

target ellipticals. We propose to observe 45 of these systems with the

ACS-WFC in order to confirm the incidence of lensing and to measure the

masses of the lens galaxies. We will complement these lensing mass

measurements with stellar velocity dispersions from ground-based

follow-up spectroscopy. In combination with similar data from the Sloan

Lens ACS (SLACS) Survey at lower redshifts, we will directly measure the

cosmic evolution of the ratio between lensing mass and dynamical mass,

to reveal the structural explanation for the observed size evolution of

elliptical galaxies (at high mass). We will also measure the evolution

of the logarithmic mass-density profile of massive ellipticals, which is

sensitive to the details of the merging histories through which they are

assembled. Finally, we will use our lensing mass-to-light measurements

to translate the BOSS galaxy luminosity function into a mass function,

and determine its evolution in combination with data from the original

Sloan Digital Sky Survey.

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/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.

FGS 12316

HST/FGS Astrometric Search for Young Planets Around Beta Pic and AU Mic

AU Mic is a nearby Vega-type debris disk stars. Its disk system has been

spatially resolved in exquisite detail, predominantly via the ACS

coronagraph and WFPC-2 cameras onboard HST. These images exhibit a

wealth of morphological features which provide compelling indirect

evidence that AU Mic likely harbors short-period planetary body(ies). We

propose to use the superlative astrometric capabilities of HST/FGS to

directly detect these planets, hence provide the first direct planet

detection in a Vega-type system whose disk has been imaged at high

spatial resolution.

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 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 11999

JWST Calibration from a Consistent Absolute Calibration of Spitzer &

Hubble

Recently, Gordon, Bohlin, et al. submitted a successful Spitzer proposal

for cross calibration of HST and Spitzer. The cross-calibration targets

are stars in three categories: WDs, A-stars, and G-stars. Traditionally,

IR flux standards are extrapolations of stellar models that are tied to

absolute fluxes at shorter wavelengths. HST absolute flux standards are

among the best available with a solid basis that uses pure hydrogen

models of hot WD stars for the SED slopes and is tied to Vega at 5556A

via precise Landolt V-band photometry. Consistently matching models to

our three categories of HST observations along with Spitzer photometry

and the few existing absolute IR flux determinations will provide a

solid basis for JWST flux calibration over its 0.8-30micron range. The

goal of this proposal is to complete the HST observations of the set of

HST/Spitzer cross-calibration stars. Using a variety of standard stars

with three different spectral types will ensure that the final

calibration is not significantly affected by systematic uncertainties.

WFC3/ACS/IR 11563

Galaxies at z~7-10 in the Reionization Epoch: Luminosity Functions to

<0.2L* from Deep IR Imaging of the HUDF and HUDF05 Fields

The first generations of galaxies were assembled around redshifts

z~7-10+, just 500-800 Myr after recombination, in the heart of the

reionization of the universe. We know very little about galaxies in this

period. Despite great effort with HST and other telescopes, less than

~15 galaxies have been reliably detected so far at z>7, contrasting with

the ~1000 galaxies detected to date at z~6, just 200-400 Myr later, near

the end of the reionization epoch. WFC3 IR can dramatically change this

situation, enabling derivation of the galaxy luminosity function and its

shape at z~7-8 to well below L*, measurement of the UV luminosity

density at z~7-8 and z~8-9, and estimates of the contribution of

galaxies to reionization at these epochs, as well as characterization of

their properties (sizes, structure, colors). A quantitative leap in our

understanding of early galaxies, and the timescales of their buildup,

requires a total sample of ~100 galaxies at z~7-8 to ~29 AB mag. We can

achieve this with 192 WFC3 IR orbits on three disjoint fields

(minimizing cosmic variance): the HUDF and the two nearby deep fields of

the HUDF05. Our program uses three WFC3 IR filters, and leverages over

600 orbits of existing ACS data, to identify, with low contamination, a

large sample of over 100 objects at z~7-8, a very useful sample of ~23

at z~8-9, and limits at z~10. By careful placement of the WFC3 IR and

parallel ACS pointings, we also enhance the optical ACS imaging on the

HUDF and a HUDF05 field. We stress (1) the need to go deep, which is

paramount to define L*, the shape, and the slope alpha of the luminosity

function (LF) at these high redshifts; and (2) the far superior

performance of our strategy, compared with the use of strong lensing

clusters, in detecting significant samples of faint z~7-8 galaxies to

derive their luminosity function and UV ionizing flux. Our recent z~7.4

NICMOS results show that wide-area IR surveys, even of GOODS-like depth,

simply do not reach faint enough at z~7-9 to meet the LF and UV flux

objectives. In the spirit of the HDF and the HUDF, we will waive any

proprietary period, and will also deliver the reduced data to STScI. The

proposed data will provide a Legacy resource of great value for a wide

range of archival science investigations of galaxies at redshifts z~2-

9. The data are likely to remain the deepest IR/optical images until

JWST is launched, and will provide sources for spectroscopic follow up

by JWST, ALMA and EVLA.

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 12324

The Temperature Profiles of Quasar Accretion Disks

We can now routinely measure the size of quasar accretion disks using

gravitational microlensing of lensed quasars. At optical wavelengths we

observe a size and scaling with black hole mass roughly consistent with

thin disk theory but the sizes are larger than expected from the

observed optical fluxes. One solution would be to use a flatter

temperature profile, which we can study by measuring the wavelength

dependence of the disk size over the largest possible wavelength

baseline. Thus, to understand the size discrepancy and to probe closer

to the inner edge of the disk we need to extend our measurements to UV

wavelengths, and this can only be done with HST. For example, in the UV

we should see significant changes in the optical/UV size ratio with

black hole mass. We propose monitoring 5 lenses spanning a broad range

of black hole masses with well-sampled ground based light curves,

optical disk size measurements and known GALEX UV fluxes during Cycles

17 and 18 to expand from our current sample of two lenses. We would

obtain 5 observations of each target in each Cycle, similar to our

successful strategy for the first two targets.

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/IR 11702

Search for Very High-z Galaxies with WFC3 Pure Parallel

WFC3 will provide an unprecedented probe to the early universe beyond

the current redshift frontier. Here we propose a pure parallel program

using this new instrument to search for Lyman-break galaxies at

6.5<z<8.8 and to probe the epoch of reionization, a hallmark event in

the history of the early universe. We request 200 orbits, spreading over

30 ~ 50 high Galactic latitude visits (|b|>20deg) that last for 4 orbits

and longer, resulting a total survey area of about 140~230 square

arcminute. Based on our understanding of the new HST parallel

observation scheduling process, we believe that the total number of

long-duration pure parallel visits in Cycle 17 should be sufficient to

accommodate our program. We waive all proprietary rights to our data,

and will also make the enhanced data products public in a timely manner.

(1) We will use both the UVIS and the IR channels, and do not need to

seek optical data from elsewhere.

(2) Our program will likely triple the size of the probable candidate

samples at z~7 and z~8, and will complement other targeted programs

aiming at the similar redshift range.

(3) Being a pure parallel program, our survey will only make very

limited demand on the scarce HST resources. More importantly, as the

pure parallel pointings will be at random sight-lines, our program will

be least affected by the bias due to the large scale structure ("cosmic

variance").

(4) We aim at the most luminous LBG population, and will address the

bright-end of the luminosity function at z~8 and z~7. We will constrain

the value of L* in particular, which is critical for understanding the

star formation process and the stellar mass assembly history in the

first few hundred million years of the universe.

(5) The candidates from our survey, 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.

(6) 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.

Lynn F. Bassford               office#: 301-286-2876  
Hubble Space Telescope
CHAMP Mission Operations Manager
CHAMP Flight Operations Team Manager
Lockheed Martin Mission Services (LMMS)