HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT      #4953

 

PERIOD COVERED: 5am October 16 - 5am October 19, 2009 (DOY 289/09:00z-292/09:00z)

 

OBSERVATIONS SCHEDULED

 

NIC1/NIC2/NIC3 8795

 

NICMOS Post-SAA Calibration - CR Persistence Part 6

 

This is a new procedure proposed to alleviate the CR-persistence problem

of NICMOS. Dark frames will be obtained immediately upon exiting the SAA

contour 23, and every time a NICMOS exposure is scheduled within 50

minutes of coming out of the SAA. The darks will be obtained in parallel

in all three NICMOS cameras. The post-SAA darks will be non-standard

reference files available to users with a 'Use After' date/time mark.

The keyword 'UseAfter=date/time' will also be added to the header of

each post-SAA dark frame. The keyword must be populated with the time,

in addition to the date, because HST crosses the SAA ~8 times per day,

so each post-SAA dark will need to have the appropriate time specified,

for users to identify the ones they need. Both the raw and processed

images will be archived as post-SAA darks. Generally we expect that all

NICMOS science/calibration observations started within 50 minutes of

leaving an SAA will need such MAPs to remove the CR persistence from the

science images. Each observation will need its own CRMAP, as different

SAA passages leave different imprints on the NICMOS detectors.

 

NIC1/NIC2/NIC3 11947

 

Extended Dark Monitoring

 

This program takes a series of darks to obtain darks (including

amplifier glow, dark current, and shading profiles) for all three

cameras in the read-out sequences used in Cycle 17. A set of 12 orbits

will be observed every two months for a total of 72 orbits for a 12

month Cycle 17. This is a continuation of Cycle 16 program 11330 scaled

down by ~80%.

 

The first orbit (Visit A0) should be scheduled in the NICMOS SMOV after

the DC Transfer Test (11406) and at least 36h before the Filter Wheel

Test (11407). Data download using fast track.

 

The following 28 orbits (visit A1-N2) should be scheduled AFTER the SMOV

Proposal 11407 (Filter Wheel Test). This is done in order to monitor the

dark current following an adjustment of the NCS set-point. These visits

should be executed until the final temperature is reached during SMOV.

 

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/IR 11909

 

UVIS Hot Pixel Anneal

 

The on-orbit radiation environment of WFC3 will continually generate new

hot pixels. This proposal performs the procedure required for repairing

those hot pixels in the UVIS CCDs. During an anneal, the two-stage

thermo-electric cooler (TEC) is turned off and the four-stage TEC is

used as a heater to bring the UVIS CCDs up to ~20 deg. C. As a result of

the CCD warmup, a majority of the hot pixels will be fixed; previous

instruments such as WFPC2 and ACS have seen repair rates of about 80%.

Internal UVIS exposures are taken before and after each anneal, to allow

an assessment of the procedure's effectiveness in WFC3, provide a check

of bias, global dark current, and hot pixel levels, as well as support

hysteresis (bowtie) monitoring and CDBS reference file generation. One

IR dark is taken after each anneal, to provide a check of the IR

detector.

 

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 11907

 

UVIS Cycle 17 Contamination Monitor

 

The UV throughput of WFC3 during Cycle 17 is monitored via weekly

standard star observations in a subset of key filters covering 200-600nm

and F606W, F814W as controls on the red end. The data will provide a

measure of throughput levels as a function of time and wavelength,

allowing for detection of the presence of possible contaminants.

 

WFC3/UV 11906

 

WFC3 UVIS CCD Gain

 

The absolute gain of each quadrant of the WFC3 UVIS detector will be

measured for the nominal detector readout configuration and at the

on-orbit operating temperature.

 

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).

 

ACS/WFC3 11879

 

CCD Daily Monitor (Part 1)

 

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 352 orbits (22 weeks) from 31 August 2009 to 31 January

2010.

 

FGS 11875

 

Monitoring FGS2R2 Distortion and Alignment After SMOV4

 

This proposal monitors changes in the FGS2R2 distortion and alignment

after SMOV4 by observing selected stars in M35 in Position mode. Data

from each epoch are compared to track changes in FGS2R2. When the rate

of change becomes sufficiently slow, FGS2R2 will be cleared for a

mini-OFAD and FGS-FGS alignment calibration (carried out in another

phase 2 proposal).

 

FGS 11874

 

Monitoring FGS2R2 S-Curves after SMOV4

 

This proposal satisfies the near-term requirement associated with SMOV4

activity OTA/FGS-10, as well as the long term Cycle 17 requirement to

monitor the post-SM4 evolution of the FGS2R2 S-curves stability during

its first year on orbit. The S-curves will be obtained from Trans mode

observations of stars (point sources) at several locations in the FGS2R2

FOV in order to monitor both global and differential (i.e.,

field-dependent) changes. At each location, both F583W and PUPIL

S-curves will be obtained. Stars in the M35 cluster will be used for

this proposal since the field lies very near the ecliptic and can

therefore be observed by HST at two Orients from August to May.

 

STIS/CCD 11846

 

CCD Bias Monitor-Part 1

 

The purpose of this proposal is to 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 11844

 

CCD Dark Monitor Part 1

 

The purpose of this proposal is to monitor the darks for the STIS CCD.

 

ACS/WFC 11840

 

Identifying the Host Galaxies for Optically Dark Gamma-ray Bursts

 

We propose to use the high spatial resolution of Chandra to obtain

precise positions for a sample of Gamma-Ray Bursts (GRBs) with no

optical afterglows, where the optical light is suppressed relative to

the X-ray flux. These bursts are likely to be highly obscured and may

have different environments from the optically bright GRBs. Our Chandra

observations will (unlike Swift XRT positions) allow for the unique

identification of a host galaxy. To locate these host galaxies we will

follow up our Chandra positions with deep optical and IR observations

with HST. The ultimate aim is to understand any differences between the

host galaxies of optically dark and bright GRBs, and how these affect

the use of GRBs as tracers of starformation and galaxy evolution at high

redshift.

 

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.

 

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.

 

WFC3/IR 11694

 

Mapping the Lnteraction Between High-Redshift Galaxies and the

Lntergalactic Environment

 

With the commissioning of the high-throughput large-area camera WFC3/IR,

it is possible for the first time to undertake an efficient survey of

the rest-frame optical morphologies of galaxies at the peak epoch of

star formation in the universe. We therefore propose deep WFC3/IR

imaging of over 320 spectroscopically confirmed galaxies between

redshift 1.6 < z < 3.4 in well-studied fields which lie along the line

of sight to bright background QSOs. The spectra of these bright QSOs

probe the IGM in the vicinity of each of the foreground galaxies along

the line of sight, providing detailed information on the physical state

of the gas at large galactocentric radii. In combination with our

densely sampled UV/IR spectroscopy, stellar population models, and

kinematic data in these fields, WFC3/IR imaging data will permit us to

construct a comprehensive picture of the structure, dynamics, and star

formation properties of a large population of galaxies in the early

universe and their effect upon their cosmological environment.

 

WFC3/UVIS 11657

 

The Population of Compact Planetary Nebulae in the Galactic Disk

 

We propose to secure narrow- and broad-band images of compact planetary

nebulae (PNe) in the Galactic Disk to study the missing link of the

early phases of post-AGB evolution. Ejected AGB envelopes become PNe

when the gas is ionized. PNe expand, and, when large enough, can be

studied in detail from the ground. In the interim, only the HST

capabilities can resolve their size, morphology, and central stars. Our

proposed observations will be the basis for a systematic study of the

onset of morphology. Dust properties of the proposed targets will be

available through approved Spitzer/IRS spectra, and so will the

abundances of the alpha- elements. We will be able thus to explore the

interconnection of morphology, dust grains, stellar evolution, and

populations. The target selection is suitable to explore the nebular and

stellar properties across the galactic disk, and to set constraints on

the galactic evolutionary models through the analysis of metallicity and

population gradients.

 

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.

 

WFC3/IR 11618

 

WFC3 Observations of VeLLOs and the Youngest Star Forming Environments

 

The Cores-to-Disks Spitzer Legacy team has discovered a number of

extremely low luminosity sources embedded deep within nearby (< 300 pc)

cores previously thought to be starless. With substellar masses, these

low luminosity sources represent either the youngest low-mass protostars

yet detected or the first embedded brown dwarfs. In either case, they

represent a new observed class of sources referred to as VeLLOs (Very

Low Luminosity Objects). We propose WFC3 F160W observations of a small

sample of these sources, to be combined with deep ground-based

observations at Ks, to address a broad set of issues concerning VeLLOs

and the environments within which they are forming. First, the

morphology of their outflow cavities will be traced, yielding estimates

of the inclinations and opening angles of the cavities and the

evolutionary stages of the VeLLOs. Second, our observations will reveal

background stars seen through the densest regions of cores harboring

these VeLLOs. The color-excesses of the background stars will yield the

highest angular resolution extinction maps necessary to directly probe

the inner density structure of these cores, found very soon after the

onset of collapse, which would constrain the initial conditions of

collapse within these isolated environments. In addition, we will

construct similar maps of the dense pre-protostellar core L694-2 and the

protostellar core B335. These maps will provide a snapshot of the

evolution of the inner density structure of a core prior to low-mass

star formation and soon thereafter, for comparison with the inner

density structure of cores that have formed VeLLOs. Finally, these

extinction maps will enable us to determine the core "centers", or

positions of peak column densities. Comparison of these centers with the

positions of the VeLLOs may yield insight regarding potential

differences between the formation of low-mass stars and brown dwarfs.

 

ACS/WFC3 11599

 

Distances of Planetary Nebulae from SNAPshots of Resolved Companions

 

Reliable distances to individual planetary nebulae (PNe) in the Milky

Way are needed to advance our understanding of their spatial

distribution, birthrates, influence on galactic chemistry, and the

luminosities and evolutionary states of their central stars (CSPN). Few

PNe have good distances, however. One of the best ways to remedy this

problem is to find resolved physical companions to the CSPN and measure

their distances by photometric main-sequence fitting. We have previously

used HST to identify and measure probable companions to 10 CSPN, based

on angular separations and statistical arguments only. We now propose to

use HST to re-observe 48 PNe from that program for which additional

companions are possibly present. We then can use the added criterion of

common proper motion to confirm our original candidate companions and

identify new ones in cases that could not confidently be studied before.

We will image the region around each CSPN in the V and I bands, and in

some cases in the B band. Field stars that appear close to the CSPN by

chance will be revealed by their relative proper motion during the 13+

years since our original survey, leaving only genuine physical

companions in our improved and enlarged sample. This study will increase

the number of Galactic PNe with reliable distances by 50 percent and

improve the distances to Pne with previously known companions.

 

ACS/WFC3 11586

 

Exceptional Galactic Halo Globular Clusters and the Second Parameter

 

We propose to obtain deep ACS-WFC images of six globular clusters (five

of which have no previous HST photometry) that reside in the Galactic

halo, where the second parameter effect is most pronounced. These

globular clusters are among the least studied in the Galaxy and yet,

from the perspective of the second parameter phenomenon, the most

intriguing.

 

With the best available CMDs only reaching the vicinity of the main

sequence turn off at present, the unique sensitivity and resolution of

ACS-WFC will yield ages of unprecedented precision for these clusters.

These data will provide us with new insight into the stellar populations

present in the outer Galactic halo and the nature of the second

parameter. The second parameter plays a critical role in our

understanding of the formation and evolution of the Galaxy and the

proposed observations will shed new light on this problem and these

exceptional clusters.

 

WFC3/UVIS 11565

 

A Search for Astrometric Companions to Very Low-Mass, Population II

Stars

 

We propose to carry out a Snapshot search for astrometric companions in

a subsample of very low-mass, halo subdwarfs identified within 120

parsecs of the Sun. These ultra-cool M subdwarfs are local

representatives of the lowest-mass H burning objects from the Galactic

Population II. The expected 3-4 astrometric doubles that will be

discovered will be invaluable in that they will be the first systems

from which gravitational masses of metal-poor stars at the bottom of the

main sequence can be directly measured.

 

NIC2/WFC3/IR 11548

 

Infrared Imaging of Protostars in the Orion A Cloud: The Role of

Environment in Star Formation

 

We propose NICMOS and WFC3/IR observations of a sample of 252 protostars

identified in the Orion A cloud with the Spitzer Space Telescope. These

observations will image the scattered light escaping the protostellar

envelopes, providing information on the shapes of outflow cavities, the

inclinations of the protostars, and the overall morphologies of the

envelopes. In addition, we ask for Spitzer time to obtain 55-95 micron

spectra of 75 of the protostars. Combining these new data with existing

3.6 to 70 micron photometry and forthcoming 5-40 micron spectra measured

with the Spitzer Space Telescope, we will determine the physical

properties of the protostars such as envelope density, luminosity,

infall rate, and outflow cavity opening angle. By examining how these

properties vary with stellar density (i.e. clusters vs. groups vs.

isolation) and the properties of the surrounding molecular cloud; we can

directly measure how the surrounding environment influences protostellar

evolution, and consequently, the formation of stars and planetary

systems. Ultimately, this data will guide the development of a theory of

protostellar evolution.

 

COS/NUV/FUV/WFC3/UVI 11534 S/IR COS-GTO: Atmosphere of a Transiting

Planet

 

COS observations of a transiting planet at different orbital locations

will be useful in identifying the chemical content, size, temperature,

and flows in the atmosphere of a transiting planet.

 

WFC3/IR 11202

 

The Structure of Early-type Galaxies: 0.1-100 Effective Radii

 

The structure, formation and evolution of early-type galaxies is still

largely an open problem in cosmology: how does the Universe evolve from

large linear scales dominated by dark matter to the highly non-linear

scales of galaxies, where baryons and dark matter both play important,

interacting, roles? To understand the complex physical processes

involved in their formation scenario, and why they have the tight

scaling relations that we observe today (e.g. the Fundamental Plane), it

is critically important not only to understand their stellar structure,

but also their dark-matter distribution from the smallest to the largest

scales. Over the last three years the SLACS collaboration has developed

a toolbox to tackle these issues in a unique and encompassing way by

combining new non-parametric strong lensing techniques, stellar

dynamics, and most recently weak gravitational lensing, with

high-quality Hubble Space Telescope imaging and VLT/Keck spectroscopic

data of early-type lens systems. This allows us to break degeneracies

that are inherent to each of these techniques separately and probe the

mass structure of early-type galaxies from 0.1 to 100 effective radii.

The large dynamic range to which lensing is sensitive allows us both to

probe the clumpy substructure of these galaxies, as well as their

low-density outer haloes. These methods have convincingly been

demonstrated, by our team, using smaller pilot-samples of SLACS lens

systems with HST data. In this proposal, we request observing time with

WFC3 and NICMOS to observe 53 strong lens systems from SLACS, to obtain

complete multi-color imaging for each system. This would bring the total

number of SLACS lens systems to 87 with completed HST imaging and

effectively doubles the known number of galaxy-scale strong lenses. The

deep HST images enable us to fully exploit our new techniques, beat down

low-number statistics, and probe the structure and evolution of early-

type galaxies, not only with a uniform data-set an order of magnitude

larger than what is available now, but also with a fully-coherent and

self-consistent methodological approach!

 

WFC3/IR 11108

 

Near Infrared Observations of a Sample of z~6.5-6.7 Galaxies

 

The majority of the most distant galaxies discovered to date have been

found by strong Lyman alpha emission at red optical wavelengths. An

accurate estimate of the star formation rates for these objects requires

a measurement of the line-free UV continuum, which must be taken at

infrared wavelengths. Here we propose to obtain imaging with WFC3 in the

F140W filter for a sample of 9 Lyman alpha galaxies with redshifts z~6.5

up to z=6.740 from a complete, flux- limited widefield narrowband and

multi-color survey conducted on the 8-m Subaru Telescope. This program

will investigate galaxy morphologies and star formation for a uniform

sample of the highest redshift galaxies now known.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS:

12043 - GSAcq(2,1,1) failed to RGA hold due to Search Radius Limit

           Exceeded on FGS-2 @ 290/08:57:30z

 

           Observations affected: NICMOS 45 Proposal ID# 11947, ACS 78-81

           Proposal ID# 11586.

 

12044 - REAcq(2,1,1) scheduled at 290/10:27:34z - 290/10:32:00z was

           successful. At 290/11:16:58z, search radius limit exceeded on FGS-2

           (QF2SRLEX) was received. A possible Loss of Lock occurred while guiding

           under FGS-1 and FGS-2. RGA Gyro Hold began 11min before expected TERM EXP.

 

           Observations possibly affected: WFC3 190-192 Proposal ID#11618.

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                        SCHEDULED      SUCCESSFUL      FAILURE TIMES

FGS GSAcq                29                   28                    

FGS REAcq                15                   15                

OBAD with Maneuver  20                   20       

LOSS of LOCK                                                   290/11:14:31z

 

SIGNIFICANT EVENTS: (None)