HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5141

PERIOD COVERED: 5am July 19 - 5am July 20, 2010 (DOY 200/09:00z-201/09:00z)

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

HSTARS:

#12333 OBAD at 200/17:21:57z failed and GSAcq(1,2,1) at 200/17:26:57z

              failed with search radius limit exceeded on FGS2

              Observations affected: Astrometry Proposal #12316

From DOY 187:

#12334 ReAcq(1,0,1) at 187/04:37:32z required two attempts for FL-DV with scan

              step limit exceeded on FGS1

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                            SCHEDULED      SUCCESSFUL      

FGS GSAcq                     9               8                    

FGS REAcq                     7               7        

OBAD with Maneuver      6               5                    

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.

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/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.

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.

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/CCD 11721

Verifying the Utility of Type Ia Supernovae as Cosmological Probes:

Evolution and Dispersion in the Ultraviolet Spectra

The study of distant type Ia supernova (SNe Ia) offers the most

practical and immediate discriminator between popular models of dark

energy. Yet fundamental questions remain over possible

redshift-dependent trends in their observed and intrinsic properties.

High-quality Keck spectroscopy of a representative sample of 36

intermediate redshift SNe Ia has revealed a surprising, and unexplained,

diversity in their rest-frame UV fluxes. One possible explanation is

hitherto undiscovered variations in the progenitor metallicity.

Unfortunately, this result cannot be compared to local UV data as only

two representative SNe Ia have been studied near maximum light. Taking

advantage of two new `rolling searches' and the restoration of STIS, we

propose a non-disruptive TOO campaign to create an equivalent comparison

local sample. This will allow us to address possible evolution in the

mean UV spectrum and its diversity, an essential precursor to the study

of SNe beyond z~1.

STIS/CCD/MA2 11568

A SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations

of Stars with Archived FUV Observations

We propose to obtain high-resolution STIS E230H SNAP observations of

MgII and FeII interstellar absorption lines toward stars within 100

parsecs that already have moderate or high-resolution far-UV (FUV),

900-1700 A, observations available in the MAST Archive. Fundamental

properties, such as temperature, turbulence, ionization, abundances, and

depletions of gas in the local interstellar medium (LISM) can be

measured by coupling such observations. Due to the wide spectral range

of STIS, observations to study nearby stars also contain important data

about the LISM embedded within their spectra. However, unlocking this

information from the intrinsically broad and often saturated FUV

absorption lines of low-mass ions, (DI, CII, NI, OI), requires first

understanding the kinematic structure of the gas along the line of

sight. This can be achieved with high resolution spectra of high-mass

ions, (FeII, MgII), which have narrow absorption lines, and can resolve

each individual velocity component (interstellar cloud). By obtaining

short (~10 minute) E230H observations of FeII and MgII, for stars that

already have moderate or high- resolution FUV spectra, we can increase

the sample of LISM measurements, and thereby expand our knowledge of the

physical properties of the gas in our galactic neighborhood. STIS is the

only instrument capable of obtaining the required high resolution data

now or in the foreseeable future.

STIS/MA1/MA2 11857

STIS Cycle 17 MAMA Dark Monitor

This proposal monitors the behavior of the dark current in each of the

MAMA detectors.

The basic monitor takes two 1380s ACCUM darks each week with each

detector. However, starting Oct 5, pairs are only included for weeks

that the LRP has external MAMA observations planned. The weekly pairs of

exposures for each detector are linked so that they are taken at

opposite ends of the same SAA free interval. This pairing of exposures

will make it easier to separate long and short term temporal variability

from temperature dependent changes.

For both detectors, additional blocks of exposures are taken once every

six months. These are groups of five 1314s FUV-MAMA Time-Tag darks or

five 3x315s NUV ACCUM darks distributed over a single SAA-free interval.

This will give more information on the brightness of the FUV MAMA dark

current as a function of the amount of time that the HV has been on, and

for the NUV MAMA will give a better measure of the short term

temperature dependence.

WFC3/ACS/UVIS/IR 11570

Narrowing in on the Hubble Constant and Dark Energy

A measurement of the Hubble constant to a precision of a few percent

would be a powerful aid to the investigation of the nature of dark

energy and a potent "end-to end" test of the present cosmological model.

In Cycle 15 we constructed a new streamlined distance ladder utilizing

high- quality type Ia supernova data and observations of Cepheids with

HST in the near-IR to minimize the dominant sources of systematic

uncertainty in past measurements of the Hubble constant and reduce its

total uncertainty to a little under 5%. Here we propose to exploit this

new route to reduce the remaining uncertainty by more than 30%,

translating into an equal reduction in the uncertainty of the equation

of state of dark energy. We propose three sets of observations to reach

this goal: a mosaic of NGC 4258 with WFC3 in F160W to triple its sample

of long period Cepheids, WFC3/F160W observations of the 6 ideal SN Ia

hosts to triple their samples of Cepheids, and observations of NGC 5584

the host of a new SN Ia, SN 2007af, to discover and measure its Cepheids

and begin expanding the small set of SN Ia luminosity calibrations.

These observations would provide the bulk of a coordinated program aimed

at making the measurement of the Hubble constant one of the leading

constraints on dark energy.

WFC3/IR 11591

Are Low-Luminosity Galaxies Responsible for Cosmic Reionization?

Our group has demonstrated that massive clusters, acting as powerful

cosmic lenses, can constrain the abundance and properties of

low-luminosity star-forming sources beyond z~6; such sources are thought

to be responsible for ending cosmic reionization. The large

magnification possible in the critical regions of well-constrained

clusters brings sources into view that lie at or beyond the limits of

conventional exposures such as the UDF. We have shown that the

combination of HST and Spitzer is particularly effective in delivering

the physical properties of these distant sources, constraining their

mass, age and past star formation history. Indirectly, we therefore gain

a valuable glimpse to yet earlier epochs. Recognizing the result (and

limitations) of blank field surveys, we propose a systematic search

through 10 lensing clusters with ACS/F814W and WFC3/[F110W+F160W] (in

conjunction with existing deep IRAC data). Our goal is to measure with

great accuracy the luminosity function at z~7 over a range of at least 3

magnitude, based on the identification of about 50 lensed galaxies at

6.5<z<8. Our survey will mitigate cosmic variance and extend the search

both to lower luminosities and, by virtue of the WFC3/IRAC combination,

to higher redshift. Thanks to the lensing amplification spectroscopic

follow-up will be possible and make our findings the most robust prior

to the era of JWST and the ELTs.

WFC3/IR 11666

Chilly Pairs: A Search for the Latest-type Brown Dwarf Binaries and the

Prototype Y Dwarf

We propose to use HST/WFC3 to image a sample of 27 of the nearest (< 20

pc) and lowest luminosity T-type brown dwarfs in order to identify and

characterize new very low mass binary systems. Only 3 late-type T dwarf

binaries have been found to date, despite that fact that these systems

are critical benchmarks for evolutionary and atmospheric models at the

lowest masses. They are also the most likely systems to harbor Y dwarf

companions, an as yet unpopulated putative class of very cold (T < 600

K) brown dwarfs. Our proposed program will more than double the number

of T5-T9 dwarfs imaged at high resolution, with an anticipated yield of

~5 new binaries with initial characterization of component spectral

types. We will be able to probe separations sufficient to identify

systems suitable for astrometric orbit and dynamical mass measurements.

We also expect one of our discoveries to contain the first Y-type brown

dwarf. Our proposed program complements and augments ongoing

ground-based adaptive optics surveys and provides pathway science for

JWST.

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/ACS/WFC 11636

First Resolved Imaging of Escaping Lyman Continuum

The emission from star-forming galaxies appears to be responsible for

reionization of the universe at z > 6. However, the models that attempt

to describe the detailed impact of high-redshift galaxies on the

surrounding inter-galactic medium (IGM) are strongly dependent upon

several uncertain parameters. Perhaps the most uncertain is the fraction

of HI-ionizing photons produced by young stars that escape into the IGM.

Most attempts to measure this "escape fraction" have produced null

results. Recently, a small subset of z~3 Lyman Break Galaxies (LBGs) has

been found exhibiting large escape fractions. It remains unclear

however, what differentiates them from other LBGs. Several models

attempt to explain how such a large fraction of ionizing continuum can

escape through the HI and dust in the ISM (eg. "chimneys" created by SNe

winds, globular cluster formation, etc.), each producing unique

signatures which can be observed with resolved imaging of the escaping

Lyman continuum. To date, there are only six LBGs with individual

detections of escaping Lyman continuum at any redshift. We propose a

single deep, high resolution WFC3/UVIS image of the ionizing continuum

(F336W) and the rest-frame UV/optical (F606W/F814W/F160W) of five of

these six LBGs with large escape fractions. These LBGs have a high

surface density and large escape fractions, and lie at the optimal

redshift for Lyman continuum imaging with UVIS filters, making our

sample especially suitable for follow-up. With these data we will

discern the mechanisms responsible for producing large escape fractions,

and therefore gain insight into the process of reionization.

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.

-Lynn               

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

"...Hubble is the most significant science instrument of all time in terms of its productivity..."     Scott Altman @12:45pm 5/21/9 STS-125 Senate Subcommittee Hearing