HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT #5108

 

PERIOD COVERED: 5am June 1 - 5am June 2, 2010 (DOY 152/09:00z-153/09:00z)

 

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               8              8

FGS REAcq               5               5

OBAD with Maneuver 6               6

 

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.

 

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. 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/FUV 11692

 

The LMC as a QSO Absorption Line System

 

We propose to obtain high resolution, high signal-to-noise observations

of QSOs behind the Large Magellanic Clouds. These QSOs are situated

beyond the star forming disk of the galaxy, giving us the opportunity to

study the distribution of metals and energy in regions lacking

significant star formation. In particular, we will derive the

metallicities and study the ionization characteristics of LMC gas at

impact parameters 3-17 kpc. We will compare our results with high-z QSO

absorption line systems.

 

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 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.

 

FGS 11788

 

The Architecture of Exoplanetary Systems

 

Are all planetary systems coplanar? Concordance cosmogony makes that

prediction. It is, however, a prediction of extrasolar planetary system

architecture as yet untested by direct observation for main sequence

stars other than the Sun. To provide such a test, we propose to carry

out FGS astrometric studies on four stars hosting seven companions. Our

understanding of the planet formation process will grow as we match not

only system architecture, but formed planet mass and true distance from

the primary with host star characteristics for a wide variety of host

stars and exoplanet masses.

 

We propose that a series of FGS astrometric observations with

demonstrated 1 millisecond of arc per-observation precision can

establish the degree of coplanarity and component true masses for four

extrasolar systems: HD 202206 (brown dwarf+planet); HD 128311

(planet+planet), HD 160691 = mu Arae (planet+planet), and HD 222404AB =

gamma Cephei (planet+star). In each case the companion is identified as

such by assuming that the minimum mass is the actual mass. For the last

target, a known stellar binary system, the companion orbit is stable

only if coplanar with the AB binary orbit.

 

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 11712

 

Calibration of Surface Brightness Fluctuations for WFC3/IR

 

We aim to characterize galaxy surface brightness fluctuations (SBF), and

calibrate the SBF distance method, in the F110W and F160W filters of the

Wide Field Camera 3 IR channel. Because of the very high throughput of

F110W and the good match of F160W to the standard H band, we anticipate

that both of these filters will be popular choices for galaxy

observations with WFC3/IR. The SBF signal is typically an order of

magnitude brighter in the near-IR than in the optical, and the

characterisitics (sensitivity, FOV, cosmetics) of the WFC3/IR channel

will be enormously more efficient for SBF measurements than previously

available near-IR cameras. As a result, our proposed SBF calibration

will allow accurate distance derivation whenever an early-type or

bulge-dominated galaxy is observed out to a distance of 150 Mpc or more

(i.e., out to the Hubble flow) in the calibrated passbands. For

individual galaxy observations, an accurate distance is useful for

establishing absolute luminosities, black hole masses, linear sizes,

etc. Eventually, once a large number of galaxies have been observed

across the sky with WFC3/IR, this SBF calibration will enable accurate

mapping of the total mass density distribution in the local universe

using the data available in the HST archive. The proposed observations

will have additional important scientific value; in particular, we

highlight their usefulness for understanding the nature of multimodal

globular cluster color distributions in giant elliptical galaxies.

 

WFC3/IR 11915

 

IR Internal Flat Fields

 

This program is the same as 11433 (SMOV) and depends on the completion

of the IR initial alignment (program 11425). This version contains three

instances of 37 internal orbits; to be scheduled early, middle, and near

the end of Cycle 17, in order to use the entire 110-orbit allocation.

 

In this test, we will study the stability and structure of the IR

channel flat field images through all filter elements in the WFC3-IR

channel. Flats will be monitored, i.e. to capture any temporal trends in

the flat fields, and delta flats produced. High signal observations will

provide a map of the pixel-to-pixel flat field structure, as well as

identify the positions of any dust particles.

 

WFC3/UVI 11556

 

Investigations of the Pluto System

 

We propose a set of high SNR observations of the Pluto system that will

provide improved lightcurves, orbits, and photometric properties of Nix

and Hydra. The key photometric result for Nix and Hydra will be a vastly

improved lightcurve shape and rotation period to test if the objects are

in synchronous rotation or not. A second goal of this program will be to

retrieve a new epoch of albedo map for the surface of Pluto. These

observations will also improve masses and in some case densities for the

bodies in the Pluto system.

 

WFC3/UVI 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<BR>and dark frames. A smaller set of 2Kx4K

subarray biases are acquired at less frequent intervals<BR>throughout

the cycle to support subarray science observations. The internals from

this proposal,<BR>along with those from the anneal procedure (11909),

will be used to generate the necessary superbias<BR>and superdark

reference files for the calibration pipeline (CDBS).

 

WFC3/UVI 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.