HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science



DAILY REPORT # 4463



PERIOD COVERED: UT October 05,06,07,08, 2007 (DOY 278,279,280,281)



OBSERVATIONS SCHEDULED



NIC1/NIC2/NIC3 8795



NICMOS Post-SAA calibration - CR Persistence Part 6



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 USEAFTER 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 DARKSs. 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 i

mages. Each observation will need its own CRMAP, as different SAA

passages leave different imprints on the NICMOS detectors.



NIC1/NIC2/NIC3 8793



NICMOS Post-SAA calibration - CR Persistence Part 4



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 USEAFTER 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 DARKSs. 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.



WFPC2 11352



Mass and distance of the sub-Saturn microlensing planet

OGLE-2007-BLG-349Lb



OGLE-2007-BLG-349Lb is the seventh planet discovered using gravitational

microlensing, with planet/star mass ratio 2.8e-4. These microlensing

planets lie in the cold, outer reaches of their solar systems and are

difficult to detect by other techniques because of their long periods.

However, microlensing detections by themselves generally give only the

planet/star mass ratio, not the absolute planet mass. HST observations

have yielded host star masses and distances for two previous

microlensing planets. Here, we propose to apply a proven technique to

measure the mass and distance of the newest microlensing planet, which

was discovered only two weeks ago. We will use WFPC2 observations to

unambiguously determine whether the blended light seen during the event

is due to the host star (rather than a random interloper) and a

combination of WFPC2 and NICMOS observations to obtain photometric

estimates of the mass and distance. Two epochs of observations are

required, one at high magnification (in the very near future) and the

other at baseline (but not too late -- to avoid having the lens move

substantially away from the source).



S/C 11320



NICMOS Focus Monitoring Cycle 16



This program is a version of the standard focus sweep used since cycle

7. It has been modified to go deeper and uses more narrow filters for

improved focus determination. A new source was added in Cycle 14 in

order to accommodate 2-gyro mode: the open cluster NGC1850. This source

is part of the current proposal. The old target, the open cluster

NGC3603, will be used whenever available and the new target used to fill

the periods when NGC3603 is not visible. Steps: a) Use refined target

field positions as determined from cycle 7 calibrations b) Use

MULTIACCUM sequences of sufficient dynamic range to account for defocus

c) Do a 17-point focus sweep, +/- 8mm about the PAM mechanical zeropoint

for each cameras 1 and 2, in 1.0mm steps. For NIC3 we step from -0.5mm

to -9.5mm relative to mechanical zero, in steps of 1.0mm. d) Use PAM X/Y

tilt and OTA offset slew compensations refined from previous focus

monitoring/optical alignment activities



FGS 11295



Trigonometric Calibration of the Distance Scale for Classical Novae



The distance scale for classical novae is important for understanding

the stellar physics of their thermonuclear runaways, their contribution

to Galactic nucleosynthesis, and their use as extragalactic standard

candles. Although it is known that there is a relationship between their

absolute magnitudes at maximum light and their subsequent rates of

decline--the well-known maximum-magnitude rate-of-decline {MMRD}

relation--it is difficult to set the zero-point for the MMRD because of

the very uncertain distances of Galactic novae. We propose to measure

precise trigonometric parallaxes for the quiescent remnants of the four

nearest classical novae. We will use the Fine Guidance Sensors, which

are proven to be capable of measuring parallaxes with errors of ~0.2

mas, well below what is possible from the ground.



WFPC2 11289



SL2S: The Strong Lensing Legacy Survey



Recent systematic surveys of strong galaxy-galaxy lenses {CLASS, SLACS,

GOODS, etc.} are producing spectacular results for galaxy masses roughly

below a transition mass M~10^13 Mo. The observed lens properties and

their evolution up to z~0.2, consistent with numerical simulations, can

be described by isothermal elliptical potentials. In contrast, modeling

of giant arcs in X-ray luminous clusters {halo masses M >~10^13 Mo}

favors NFW mass profiles, suggesting that dark matter halos are not

significantly affected by baryon cooling. Until recently, lensing

surveys were neither deep nor extended enough to probe the intermediate

mass density regime, which is fundamental for understanding the assembly

of structures. The CFHT Legacy Survey now covers 125 square degrees, and

thus offers a large reservoir of strong lenses probing a large range of

mass densities up to z~1. We have extracted a list of 150 strong lenses

using the most recent CFHTLS data release via automated procedures.

Following our first SNAPSHOT proposal in cycle 15, we propose to

continue the Hubble follow-up targeting a larger list of 130 lensing

candidates. These are intermediate mass range candidates {between

galaxies and clusters} that are selected in the redshift range of 0.2-1

with no a priori X-ray selection. The HST resolution is necessary for

confirming the lensing candidates, accurate modeling of the lenses, and

probing the total mass concentration in galaxy groups up to z~1 with the

largest unbiased sample available to date.



WFPC2 11227



The orbital period for an ultraluminous X-ray source in NGC1313



The ultraluminous X-ray sources {ULXs} are extragalactic point sources

with luminosities that exceed the Eddington luminosity for conventional

stellar-mass black holes by factors of 10 - 100. It has been hotly

debated whether the ULXs are just common stellar-mass black hole sources

with beamed emission or whether they are sub-Eddington sources that are

powered by the long-sought intermediate mass black holes {IMBH}. To

firmly decide this question, one must obtain dynamical mass measurements

through photometric and spectroscopic monitoring of the secondaries of

these system. The crucial first step is to establish the orbital period

of a ULX, and arguably the best way to achieve this goal is by

monitoring its ellipsoidal light curve. The extreme ULX NGC1313 X-2

provides an outstanding target for an orbital period determination

because its relatively bright optical counterpart {V = 23.5} showed a

15% variation between two HST observations separated by three months.

This level of variability is consistent with that expected for a tidally

distorted secondary star. Here we propose a set of 20 imaging

observations with HST/WFPC2 to define the orbital period. This would be

the first photometric measurement of the orbital period of a ULX binary.

Subsequently, we will propose to obtain spectroscopic observations to

obtain its radial velocity amplitude and thereby a dynamical estimate of

its mass.



NIC2 11219



Active Galactic Nuclei in nearby galaxies: a new view of the origin of

the radio-loud radio- quiet dichotomy?



Using archival HST and Chandra observations of 34 nearby early-type

galaxies {drawn from a complete radio selected sample} we have found

evidence that the radio-loud/radio-quiet dichotomy is directly connected

to the structure of the inner regions of their host galaxies in the

following sense: [1] Radio-loud AGN are associated with galaxies with

shallow cores in their light profiles [2] Radio-quiet AGN are only

hosted by galaxies with steep cusps. Since the brightness profile is

determined by the galaxy's evolution, through its merger history, our

results suggest that the same process sets the AGN flavour. This

provides us with a novel tool to explore the co-evolution of galaxies

and supermassive black holes, and it opens a new path to understand the

origin of the radio-loud/radio-quiet AGN dichotomy. Currently our

analysis is statistically incomplete as the brightness profile is not

available for 82 of the 116 targets. Most galaxies were not observed

with HST, while in some cases the study is obstructed by the presence of

dust features. We here propose to perform an infrared NICMOS snapshot

survey of these 82 galaxies. This will enable us to i} test the reality

of the dichotomic behaviour in a substantially larger sample; ii} extend

the comparison between radio-loud and radio-quiet AGN to a larger range

of luminosities.



FGS 11212



Filling the Period Gap for Massive Binaries



The current census of binaries among the massive O-type stars is

seriously incomplete for systems in the period range from years to

millennia because the radial velocity variations are too small and the

angular separations too close for easy detection. Here we propose to

discover binaries in this observational gap through a Faint Guidance

Sensor SNAP survey of relatively bright targets listed in the Galactic O

Star Catalog. Our primary goal is to determine the binary frequency

among those in the cluster/association, field, and runaway groups. The

results will help us assess the role of binaries in massive star

formation and in the processes that lead to the ejection of massive

stars from their natal clusters. The program will also lead to the

identification of new, close binaries that will be targets of long term

spectroscopic and high angular resolution observations to determine

their masses and distances. The results will also be important for the

interpretation of the spectra of suspected and newly identified binary

and multiple systems.



WFPC2 11206



At the cradle of the Milky Way: Formation of the most massive field disk

galaxies at z>1



We propose to obtain 2 orbit WFPC2 F814W images of a sample of the 15

most massive galaxies found at $1 < z < 1.3$. These were culled from

over 20,000 Keck spectra collected as part of DEEP and are unique among

high redshift massive galaxy samples in being kinematically selected.

Through a recent HST NICMOS-2 imaging program {GO- 10532}, we have

confirmed that these galaxies have regular stellar disks, and their

emission line kinematics are not due to gradients from merging

components. These potentially very young galaxies are likely precursors

to massive local disks, assuming no further merging. The proposed WFPC2

and existing NIC-2 data provide colors, stellar masses, and ages of

bulge and disk subcomponents, to assess whether old stellar bulges and

disks are in place at that time or still being built, and constrain

their formation epochs. Finally, this sample will yield the first

statistically significant results on the $z > 1$ evolution of the

size-velocity-luminosity scaling relations, for massive galaxies at

different wavelengths, and constrain whether this evolution reflects

stellar mass growth, or passive evolution, of either bulge or disk

components.



WFPC2 11203



A Search for Circumstellar Disks and Planetary-Mass Companions around

Brown Dwarfs in Taurus



During a 1-orbit program in Cycle 14, we used WFPC2 to obtain the first

direct image of a circumstellar disk around a brown dwarf. These data

have provided fundamental new constraints on the formation process of

brown dwarfs and the properties of their disks. To search for additional

direct detections of disks around brown dwarfs and to search for

planetary-mass companions to these objects, we propose a WFPC2 survey of

32 brown dwarfs in the Taurus star-forming region.



WFPC2 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

WFPC2 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!



WFPC2 11178



Probing Solar System History with Orbits, Masses, and Colors of

Transneptunian Binaries



The recent discovery of numerous transneptunian binaries {TNBs} opens a

window into dynamical conditions in the protoplanetary disk where they

formed as well as the history of subsequent events which sculpted the

outer Solar System and emplaced them onto their present day heliocentric

orbits. To date, at least 47 TNBs have been discovered, but only about a

dozen have had their mutual orbits and separate colors determined,

frustrating their use to investigate numerous important scientific

questions. The current shortage of data especially cripples scientific

investigations requiring statistical comparisons among the ensemble

characteristics. We propose to obtain sufficient astrometry and

photometry of 23 TNBs to compute their mutual orbits and system masses

and to determine separate primary and secondary colors, roughly tripling

the sample for which this information is known, as well as extending it

to include systems of two near-equal size bodies. To make the most

efficient possible use of HST, we will use a Monte Carlo technique to

optimally schedule our observations.



WFPC2 11176



Location and the Origin of Short Gamma-Ray Bursts



During the past decade extraordinary progress has been made in

determining the origin of long-duration gamma-ray bursts. It has been

conclusively shown that these objects derive from the deaths of massive

stars. Nonetheless, the origin of their observational cousins,

short-duration gamma-ray bursts {SGRBs} remains a mystery. While SGRBs

are widely thought to result from the inspiral of compact binaries, this

is a conjecture. A number of hosts of SGRBs have been identified, and

have been used by some to argue that SGRBs derive primarily from an

ancient population {~ 5 Gyr}; however, it is not known whether this

conclusion more accurately reflects selection biases or astrophysics.

Here we propose to employ a variant of a technique that we pioneered and

used to great effect in elucidating the origins of long-duration bursts.

We will examine the degree to which SGRB locations trace the red or blue

light of their hosts, and thus old or young stellar populations. This

approach will allow us to study the demographics of the SGRB population

in a manner largely free of the distance dependent selection effects

which have so far bedeviled this field, and should give direct insight

into the age of the SGRB progenitor population.



ACS/SBC WFPC2 11175



UV Imaging to Determine the Location of Residual Star Formation in

Galaxies Recently Arrived on the Red Sequence



We have identified a sample of low-redshift {z = 0.04 - 0.10} galaxies

that are candidates for recent arrival on the red sequence. They have

red optical colors indicative of old stellar populations, but blue

UV-optical colors that could indicate the presence of a small quantity

of continuing or very recent star formation. However, their spectra lack

the emission lines that characterize star-forming galaxies. We propose

to use ACS/SBC to obtain high- resolution imaging of the UV flux in

these galaxies, in order to determine the spatial distribution of the

last episode of star formation. WFPC2 imaging will provide B, V, and I

photometry to measure the main stellar light distribution of the galaxy

for comparison with the UV imaging, as well as to measure color

gradients and the distribution of interstellar dust. This detailed

morphological information will allow us to investigate the hypothesis

that these galaxies have recently stopped forming stars and to compare

the observed distribution of the last star formation with predictions

for several different mechanisms that may quench star formation in

galaxies.



NIC2 11152



Probing the compact dust disk of a nearby Classical T Tauri Star



BP Psc is a high Galactic latitude {b = -57}, bright, IRAS source that

generally has been classified as a T Tauri star but little studied to

date. We have carried out a multiwavelength ground-based study of this

object and find that it is most likely a ~10 Myr classical T Tauri star

surrounded by a gas and dust disk, and less than 100 pc from Earth,

making it one of the oldest and closest such stars known. Near-IR AO

images and IR photometry show it is surrounded by an compact {0.2"},

almost-edge-on, optically thick disk of dust with a wide range of

temperatures. We propose a multiwavelength polarimetric study of the

compact disk to support quantitative modeling to recover disk and dust

parameters. We also propose coronagraphic imaging to search for

larger-scale dust structures invisible in ground-based images, and

narrowband imaging of an outflow jet and associated Herbig- Haro objects

to study their structure and determine a kinematic distance of the

system. A massive compact disk surrounding an isolated 10 Myr star is a

unique environment for planet formation, and its proximity to Earth

allows HST to study it in detail.



ACS/SBC 11151



Evaluating the Role of Photoevaporation of Protoplanetary Disk Dispersal



Emission produced by accretion onto the central star leads to

photoevaporation, which may play a fundamental role in disk dispersal.

Models of disk photoevaporation by the central star are challenged by

two potential problems: the emission produced by accretion will be

substantially weaker for low-mass stars, and photoevaporation must

continue as accretion slows. Existing FUV spectra of CTTSs are biased to

solar-mass stars with high accretion rates, and are therefore

insufficient to address these problems. We propose use HST/ACS SBC

PR130L to obtain FUV spectra of WTTSs and of CTTSs at low masses and

mass accretion rates to provide crucial data to evaluate

photoevaporation models. We will estimate the FUV and EUV luminosities

of low-mass CTTSs with small mass accretion rates, CTTSs with transition

disks and slowed accretion, and of magnetically-active WTTSs.



NIC2 11143



NICMOS imaging of submillimeter galaxies with CO and PAH redshifts



We propose to obtain F110W and F160W imaging of 10 z~2.4 submillimeter

galaxies {SMGs} whose optical redshifts have been confirmed by the

detection of millimeter CO and/or mid-infrared PAH emission. With the

4000A break falling within/between the two imaging filters, we will be

able to study these sources' spatially resolved stellar populations

{modulo extinction} in the rest-frame optical. SMGs' large luminosities

appear to be due largely to merger-triggered starbursts; high-resolution

NICMOS imaging will help us understand the stellar masses, mass ratios,

and other properties of the merger progenitors, valuable information in

the effort to model the mass assembly history of the universe.



WFPC2 11134



WFPC2 Tidal Tail Survey: Probing Star Cluster Formation on the Edge



The spectacular HST images of the interiors of merging galaxies such as

the Antennae and NGC 7252 have revealed rich and diverse populations of

star clusters created over the course of the interaction. Intriguingly,

our WFPC2 study of tidal tails in these and other interacting pairs has

shown that star cluster birth in the tails does not follow a similarly

straightforward evolution. In fact, cluster formation in these

relatively sparse environments is not guaranteed -- only one of six

tails in our initial study showed evidence for a significant population

of young star clusters. The tail environment thus offers the opportunity

to probe star cluster formation on the edge of the physical parameter

space {e.g., of stellar and gas mass, density, and pressure} that

permits it to occur. We propose to significantly extend our pilot sample

of optically bright, gas-rich tidal tails by a factor of 4 in number to

include a more diverse population of tails, encompassing major and minor

mergers, gas-rich and gas-poor tails, as well as early, late, and merged

interaction stages. With 21 orbits of HST WFPC2 imaging in the F606W and

F814W filters, we can identify, roughly age-date, and measure sizes of

star clusters to determine what physical parameters affect star cluster

formation. WFPC2 imaging has been used effectively in our initial study

of four mergers, and it will be possible in this program to reach

similar limits of Mv=-8.5 for each of 16 more tails. With the much

larger sample we expect to isolate which factors, such as merger stage,

HI content, and merger mass ratio, drive the formation of star clusters.



WFPC2 11130



AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge

Paradigm, Part II



The recent progress in the study of central black holes in galactic

nuclei has led to a general consensus that supermassive {10^6-10^9 solar

mass} black holes are closely connected with the formation and

evolutionary history of large galaxies, especially their bulge

component. Two outstanding issues, however, remain unresolved. Can

central black holes form in the absence of a bulge? And does the mass

function of central black holes extend below 10^6 solar masses?

Intermediate-mass black holes {<10^6 solar masses}, if they exist, may

offer important clues to the nature of the seeds of supermassive black

holes. Using the SDSS, our group has successfully uncovered a new

population of AGNs with intermediate-mass black holes that reside in

low-luminosity galaxies. However, very little is known about the

detailed morphologies or structural parameters of the host galaxies

themselves, including the crucial question of whether they have bulges

or not. Surprisingly, the majority of the targets of our Cycle 14 pilot

program have structural properties similar to dwarf elliptical galaxies.

The statistics from this initial study, however, are really too sparse

to reach definitive conclusions on this important new class of black

holes. We wish to extend this study to a larger sample, by using the

Snapshot mode to obtain WFPC2 F814W images from a parent sample of 175

AGNs with intermediate-mass black holes selected from our final SDSS

search. We are particularly keen to determine whether the hosts contain

bulges, and if so, how the fundamental plane properties of the host

depend on the mass of their central black holes. We will also

investigate the environment of this unique class of AGNs.



WFPC2 11129



The Star Formation History of the Fornax Dwarf Spheroidal Galaxy



The Fornax dwarf spheroidal galaxy is one of the most luminous dwarf

satellites of the Milky Way. It is unusual in many ways: it hosts 5

globular clusters, shows some relatively young stars, and has faint

sub-structures which have been interpreted as signs of recent

interactions. It is thus of great interest to learn the complete star

formation history {SFH} of Fornax to establish a link between its

evolutionary path and the predictions from numerical simulations, as a

test of our understanding of dwarf galaxy evolution. Yet many questions

remain open. Is the old stellar population made up of stars formed in a

very early burst, perhaps before the epoch of reionisation, or the

result of a more continuous star formation between 13 and 9 Gyr ago ?

How quickly did Fornax increase its metallicity during its initial

assembly and during subsequent episodes of star formation ? Are

accretion episodes required to explain the age-metallicity history of

Fornax ? However, there has never been a comprehensive study of the

global SFH of the Fornax field based on data of sufficient depth to

unambiguously measure the age mixture of the stellar populations and

their spatial variation. We propose to use the WFPC2 to obtain very deep

images in several fields across the central region of Fornax in order to

reach the oldest main-sequence turnoffs. The number of fields is

determined by the need to measure the SFH over different regions with

distinct kinematics and metallicity. The resolution achievable with HST

is crucial to answer these questions because, to derive the age

distribution of the oldest stars, we are interested in I magnitude

differences of the order 0.2 mag in crowded fields at V=24.5. We will

directly measure the time variation in star-formation rate over the

entire galaxy history, from first stars coeval with the Milky Way halo

to the youngest populations 200 Myr ago. The combination of detailed CMD

analysis with WFPC2 with our existing metallicity and kinematic

information will allow us to trace out the early phases of its

evolution.



NIC3 11107



Imaging of Local Lyman Break Galaxy Analogs: New Clues to Galaxy

Formation in the Early Universe



We have used the ultraviolet all-sky imaging survey currently being

conducted by the Galaxy Evolution Explorer {GALEX} to identify for the

first time a rare population of low- redshift starbursts with properties

remarkably similar to high-redshift Lyman Break Galaxies {LBGs}. These

"compact UV luminous galaxies" {UVLGs} resemble LBGs in terms of size,

SFR, surface brightness, mass, metallicity, kinematics, dust, and color.

The UVLG sample offers the unique opportunity of investigating some very

important properties of LBGs that have remained virtually inaccessible

at high redshift: their morphology and the mechanism that drives their

star formation. Therefore, in Cycle 15 we have imaged 7 UVLGs using ACS

in order to 1} characterize their morphology and look for signs of

interactions and mergers, and 2} probe their star formation histories

over a variety of timescales. The images show a striking trend of

small-scale mergers turning large amounts of gas into vigorous

starbursts {a process referred to as dissipational or "wet" merging}.

Here, we propose to complete our sample of 31 LBG analogs using the

ACS/SBC F150LP {FUV} and WFPC2 F606W {R} filters in order to create a

statistical sample to study the mechanism that triggers star formation

in UVLGs and its implications for the nature of LBGs. Specifically, we

will 1} study the trend between galaxy merging and SFR in UVLGs, 2}

artificially redshift the FUV images to z=1-4 and compare morphologies

with those in similarly sized samples of LBGs at the same rest-frame

wavelengths in e.g. GOODS, UDF, and COSMOS, 3} determine the presence

and morphology of significant stellar mass in "pre-burst" stars, and 4}

study their immediate environment. Together with our Spitzer

{IRAC+MIPS}, GALEX, SDSS and radio data, the HST observations will form

a unique union of data that may for the first time shed light on how the

earliest major episodes of star formation in high redshift galaxies came

about. This proposal was adapted from an ACS HRC+WFC proposal to meet

the new Cycle 16 observing constraints, and can be carried out using the

ACS/SBC and WFPC2 without compromising our original science goals.



WFPC2 11079



Treasury Imaging of Star Forming Regions in the Local Group:

Complementing the GALEX and NOAO Surveys



We propose to use WFPC2 to image the most interesting star-forming

regions in the Local Group galaxies, to resolve their young stellar

populations. We will use a set of filters including F170W, which is

critical to detect and characterize the most massive stars, to whose hot

temperatures colors at longer wavelengths are not sensitive. WFPC2's

field of view ideally matches the typical size of the star-forming

regions, and its spatial resolution allows us to measure individual

stars, given the proximity of these galaxies. The resulting H-R diagrams

will enable studies of star-formation properties in these regions, which

cover largely differing metallicities {a factor of 17, compared to the

factor of 4 explored so far} and characteristics. The results will

further our understanding of the star-formation process, of the

interplay between massive stars and environment, the properties of dust,

and will provide the key to interpret integrated measurements of

star-formation indicators {UV, IR, Halpha} available for several

hundreds more distant galaxies. Our recent deep surveys of these

galaxies with GALEX {FUV, NUV} and ground-based imaging {UBVRI, Halpha,

[OIII] and [SII]} provided the identification of the most relevant SF

sites. In addition to our scientific analysis, we will provide catalogs

of HST photometry in 6 bands, matched corollary ground-based data, and

UV, Halpha and IR integrated measurements of the associations, for

comparison of integrated star-formation indices to the resolved

populations. We envisage an EPO component.



WFPC2 11029



WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation Anomaly

Monitor



Intflat observations will be taken to provide a linearity check: the

linearity test consists of a series of intflats in F555W, in each gain

and each shutter. A combination of intflats, visflats, and earthflats

will be used to check the repeatability of filter wheel motions.

{Intflat sequences tied to decons, visits 1-18 in prop 10363, have been

moved to the cycle 15 decon proposal xxxx for easier scheduling.} Note:

long-exposure WFPC2 intflats must be scheduled during ACS anneals to

prevent stray light from the WFPC2 lamps from contaminating long ACS

external exposures.



WFPC2 11024



WFPC2 CYCLE 15 INTERNAL MONITOR



This calibration proposal is the Cycle 15 routine internal monitor for

WFPC2, to be run weekly to monitor the health of the cameras. A variety

of internal exposures are obtained in order to provide a monitor of the

integrity of the CCD camera electronics in both bays {both gain 7 and

gain 15 -- to test stability of gains and bias levels}, a test for

quantum efficiency in the CCDs, and a monitor for possible buildup of

contaminants on the CCD windows. These also provide raw data for

generating annual super-bias reference files for the calibration

pipeline.



WFPC2 11023



WFPC2 CYCLE 15 Standard Darks - part 1



This dark calibration program obtains dark frames every week in order to

provide data for the ongoing calibration of the CCD dark current rate,

and to monitor and characterize the evolution of hot pixels. Over an

extended period these data will also provide a monitor of radiation

damage to the CCDs.



FGS 10929



Calibrating the Mass-Luminosity Relation at the End of the Main Sequence



We propose to use HST-FGS1R to finish calibrating the mass-luminosity

relation for stars less massive than 0.5 Msun, with special emphasis on

objects near the stellar/substellar border. Our goals are to determine

Mv values to 0.05 magnitude and masses to 5%, and thereby build the

fundamental database of stellar masses that we will use to test

theoretical models as never before. This program uses the combination of

HST- FGS3/FGS1R at optical wavelengths, historical infrared speckle

data, ground-based parallax work, metallicity studies, and radial

velocity monitoring to examine nearby, subarcsecond binary systems. The

high precision separation and position angle measurements with

HST-FGS3/FGS1R {to 1 mas in the separations} for these faint {V = 10-15}

targets simply cannot be equaled by any ground-based technique. As a

result of these measurements, we are deriving high quality luminosities

and masses for the components in the systems, and characterizing their

spectral energy distributions from 0.5 to 2.2 microns. One of the

objects, GJ 1245 C with mass 0.074 +/- 0.002 Msun, is the only object

known with an accurate dynamical mass less than 0.10 Msun. The payoff of

this proposal is high because the six systems selected for final

observations in Cycles 15 and 16 have already been resolved during

Cycles 5-13 with HST FGS3/FGS1R and contain most of the reddest objects

for which accurate dynamical masses can be determined.



ACS/SBC 10872



Lyman Continuum Emission in Galaxies at z=1.2



Lyman continuum photons produced in massive starbursts may have played a

dominant role in the reionization of the Universe. Starbursts are

important contributors to the ionizing metagalactic background at lower

redshifts as well. However, their contribution to the background depends

upon the fraction of ionizing radiation that escapes from the intrinsic

opacity of galaxies below the Lyman limit. Current surveys suggest

escape fractions of a few percent, up to 10%, with very few detections

{as opposed to upper limits} having been reported. No detections have

been reported in the epochs between z=0.1 and z=2. We propose to measure

the fraction of escaping Lyman continuum radiation from 15 luminous

z~1.2 galaxies in the GOODS fields. Using the tremendous sensitivity of

the ACS Solar- blind Channel, we will reach AB=30 mag., allowing us to

detect an escape fraction of 1%. We will correlate the amount of

escaping radiation with the photometric and morphological properties of

the galaxies. A non-detection in all sources would imply that QSOs

provide the overwhelming majority of ionizing radiation at z=1.3, and it

would strongly indicate that the properties of galaxies at higher

redshift have to be significantly different for galaxies to dominate

reionization. The deep FUV images will also be useful for extending the

FUV study of other galaxies in the GOODS fields.



ACS/SBC 10864



Mapping the Gaseous Content of Protoplanetary and Young Planetary

Systems with ACS



One of the key problems in planetary system formation is understanding

how rapidly, and over what time interval Jovian planets can form. Dust

in the protoplanetary disk is critical in planetesimal formation, but it

is the gas which produces giant planets, and which is essential for

their migration. However, compared to data on the circumstellar dust,

information on the gas component is sparse, especially in the

planet-formation zone. This severely limits our ability to put

observational constraints on giant planet formation, except to note that

the process must be largely complete by 12 Myr, given the paucity of

Herbig Ae or classical T Tauri stars older than 10-12 Myr. In the FUV,

photo-excited molecular hydrogen transitions have the requisite contrast

to the stellar photosphere, accretion shock, and reflection nebulosity,

and can be traced 50-100 AU from the exciting stars in both envelopes

and outflow cavities and protoplanetary disks. Central disk cavities, an

expected consequence of planet formation, larger than 0.1" are directly

detectable in HST FUV spectra, while smaller cavities may be detected by

comparison with protoplanetary disks which are still accreting onto

their stars. We propose augmenting existing HST coronagraphic imagery of

6 Herbig Fe and T Tauri disks with ACS Solar-Blind Channel Lyman alpha

imagery and slitless spectroscopy simultaneously sampling the disk in

molecular hydrogen and small-grain reflection nebulosity. These data

will be used to quantify the amount of vertical stratification in these

disks, to map the mass-loss geometry from the star, and to determine

whether removal of molecular material precedes, lags, or is contemporary

with clearing of the dust.



WFPC2 10798



Dark Halos and Substructure from Arcs & Einstein Rings



The surface brightness distribution of extended gravitationally lensed

arcs and Einstein rings contains super-resolved information about the

lensed object, and, more excitingly, about the smooth and clumpy mass

distribution of the lens galaxies. The source and lens information can

non-parametrically be separated, resulting in a direct "gravitational

image" of the inner mass-distribution of cosmologically-distant galaxies

{Koopmans 2005; Koopmans et al. 2006 [astro-ph/0601628]}. With this goal

in mind, we propose deep HST ACS-F555W/F814W and NICMOS-F160W WFC

imaging of 20 new gravitational-lens systems with spatially resolved

lensed sources, of the 35 new lens systems discovered by the Sloan Lens

ACS Survey {Bolton et al. 2005} so far, 15 of which are being imaged in

Cycle-14. Each system has been selected from the SDSS and confirmed in

two time- efficient HST-ACS snapshot programs {cycle 13&14}.

High-fidelity multi-color HST images are required {not delivered by the

420s snapshots} to isolate these lensed images {properly cleaned,

dithered and extinction-corrected} from the lens galaxy surface

brightness distribution, and apply our "gravitational maging" technique.

Our sample of 35 early-type lens galaxies to date is by far the largest,

still growing, and most uniformly selected. This minimizes selection

biases and small-number statistics, compared to smaller, often

serendipitously discovered, samples. Moreover, using the WFC provides

information on the field around the lens, higher S/N and a better

understood PSF, compared with the HRC, and one retains high spatial

resolution through drizzling. The sample of galaxy mass distributions -

determined through this method from the arcs and Einstein ring HST

images - will be studied to: {i} measure the smooth mass distribution of

the lens galaxies {dark and luminous mass are separated using the HST

images and the stellar M/L values derived from a joint stellar-dynamical

analysis of each system}; {ii} quantify statistically and individually

the incidence of mass-substructure {with or without obvious luminous

counter- parts such as dwarf galaxies}. Since dark-matter substructure

could be more prevalent at higher redshift, both results provide a

direct test of this prediction of the CDM hierarchical

structure-formation model.



FLIGHT OPERATIONS SUMMARY:



Significant Spacecraft Anomalies: (The following are preliminary reports

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



HSTARS:

11013 - GSAcq(1,3,1) failed to RGA Hold (Gyro Control)

The GSAcq(1,3,1) scheduled at 278/12:53:30 - 13:01:34 failed to RGA Hold

due to a Search Radius Limit Exceeded Error on FGS-1. During OBAD2 at

278/12:45:03 attitude correction ESB 1806(T2G_OPEN_LOOP_TIMEOUT) was

received at 278/12:47:14 resulting in unplanned M2G transition at

278/12:47:08. Pre-acq OBAD2 had (RSS) value of 3.38 arcseconds. At

278/12:48:55 Equation F2SOB flagged indicating Stuck-on-Bottom, then

back in bounds at 278/12:49:43. Unable to execute FHST Stuck-on-Bottom

Macro due to OBAD acquisition. One (FGS Coarse Track failed -Search

Radius Limit Exceeded) was received at 278/12:59:46.



11014 - Loss of LOCK

REacq(2,3,3) at 280/09:06:48 was successful. At 09:20:02 REacq(2,3,3)

loss lock. A this time the vehicle was performing a T3 slew. The

scheduled TERM EXP was 10:00:32.



11016 - Early Loss of Lock @281/2022z

HST lost fine lock on FGS 1 and 2 at 21:14:57. P4TAKDAT (Take Data Flag)

went down at that time, causing an ACS 779 Status Buffer Message ("Fold

Mechanism Move Was Blocked") to occur at 21:15:08.



GSACQ(1,2,2) at 20:31:50 was successful but mnemonics FSUBLOL and FGSLOL

underwent a long series of limit violations beginning at 20:36:17. Both

of these are derived mnemonics based on QDFGSWT and P4CNTLST ("ST

Control Status"). P4CNTLST toggled between "RGA Only" and "FGS/RGA"

frequently from 20:38:01 to 21:14:49. Extracts for all of these

mnemonics are attached.



REACQ(1,2,2) at 22:07:11 failed while vehicle was LOS. Upon AOS at

22:47:15 QF1STOPF and QSTOP flags were set and 4 more ACS 779 messages

were received.





COMPLETED OPS REQUEST: (None)



COMPLETED OPS NOTES: (None)



SCHEDULED SUCCESSFUL FAILURE

FGS GSacq 28 27

FGS REacq 27 26

OBAD with Maneuver 110 110

LOSS of LOCK 2



SIGNIFICANT EVENTS: (None)