Notice: Due to the conversion of some ACS WFC or HRC observations into

WFPC2, or NICMOS observations after the loss of ACS CCD science

capability in January, there may be an occasional discrepancy between a

proposal's listed (and correct) instrument usage and the abstract that

follows it.

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT      # 4466

PERIOD COVERED: UT October 11, 2007 (DOY 284)

OBSERVATIONS SCHEDULED

FGS 11211

An Astrometric Calibration of Population II Distance Indicators

In 2002 HST produced a highly precise parallax for RR Lyrae. That

measurement resulted in an absolute magnitude, M{V}= 0.61+/-0.11, a

useful result, judged by the over ten refereed citations each year

since. It is, however, unsatisfactory to have the direct,

parallax-based, distance scale of Population II variables based on a

single star. We propose, therefore, to obtain the parallaxes of four

additional RR Lyrae stars and two Population II Cepheids, or W Vir

stars. The Population II Cepheids lie with the RR Lyrae stars on a

common K-band Period-Luminosity relation. Using these parallaxes to

inform that relationship, we anticipate a zero-point error of 0.04

magnitude. This result should greatly strengthen confidence in the

Population II distance scale and increase our understanding of RR Lyrae

star and Pop II Cepheid astrophysics.

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.

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.

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.

WFPC2 11039

Polarizers Closeout

Observations of standard stars and a highly polarized reflection nebula

are made as a final calibration for the WFPC2 polarizers. VISFLATS are

also obtained.

WFPC2 11103

A Snapshot Survey of The Most Massive Clusters of Galaxies

We propose the continuation of our highly successful SNAPshot survey of

a sample of 125 very X-ray luminous clusters in the redshift range

0.3-0.7. As demonstrated by the 25 snapshots obtained so far in Cycle14

and Cycle15 these systems frequently exhibit strong gravitational

lensing as well as spectacular examples of violent galaxy interactions.

The proposed observations will provide important constraints on the

cluster mass distributions, the physical nature of galaxy-galaxy and

galaxy-gas interactions in cluster cores, and a set of optically bright,

lensed galaxies for further 8-10m spectroscopy. All of our primary

science goals require only the detection and characterization of

high-surface-brightness features and are thus achievable even at the

reduced sensitivity of WFPC2. Because of their high redshift and thus

compact angular scale our target clusters are less adversely affected by

the smaller field of view of WFPC2 than more nearby systems.

Acknowledging the broad community interest in this sample we waive our

data rights for these observations. Due to a clerical error at STScI our

approved Cycle15 SNAP program was barred from execution for 3 months and

only 6 observations have been performed to date - reinstating this SNAP

at Cycle16 priority is of paramount importance to reach meaningful

statistics.

WFPC2 11126

Resolving the Smallest Galaxies

An order of magnitude more dwarf galaxies are expected to inhabit the

Local Group, based on currently accepted galaxy formation models, than

have been observed. This discrepancy has been noted in environments

ranging from the field to rich clusters, with evidence emerging that

lower density regions contain fewer dwarfs per giant than higher density

regions, in further contrast to model predictions. One possible

explanation for this involves the effects of reionization on the forming

galaxies and naturally explains both the dearth of dwarf galaxies and

the apparent environmental dependence. However, before such theories can

be fully tested, we require a better understanding of the distribution

of dwarf galaxies. Currently, there is no complete census of the

faintest dwarf galaxies in any environment. The discovery of the

smallest and faintest dwarfs is hampered by the limitations in detecting

such faint and low surface brightness galaxies, and this is compounded

by the great difficulty in determining accurate distances to, or

ascertaining group membership for, such faint objects. The M81 group

provides a unique means for establishing membership for galaxies in a

low density region complete to magnitudes as faint as M_R ~ -7. With a

distance modulus of 27.8, the tip of the red giant branch {TRGB} appears

at I ~ 24, just within the reach of ground based surveys. We currently

have surveyed a 30 square degree region around M81 with the

CFHT/Megacam. From these images we have detected 15 new candidate dwarf

galaxies. We propose to use the HST with WFPC2 to image these 15

galaxies in F606W and F814W bands in order to construct a

color-magnitude diagram down to I = 25.5 from which to measure accurate

TRGB distances to these candidate galaxies and determine star formation

and metallicity histories. The overall project will provide a survey of

the dwarf galaxies in the M81 group environment with unprecedented

completeness to a limit of M_R < -7.

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 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 11312

The Local Cluster Substructure Survey {LoCuSS}: Deep Strong Lensing

Observations with WFPC2

LoCuSS is a systematic and detailed investigation of the mass,

substructure, and thermodynamics of 100 X-ray luminous galaxy clusters

at 0.15<z<0.3. The primary goal is to test our recent suggestion that

this population is dominated by dynamically immature disturbed clusters,

and that the observed mass-temperature relation suffers strong

structural segregation. If confirmed, this would represent a paradigm

shift in our observational understanding of clusters, that were hitherto

believed to be dominated by mature, undisturbed systems. We propose to

complete our successful Cycle 15 program {SNAP:10881} which prior to

premature termination had delivered robust weak-lensing detections in 17

clusters, and candidate strongly-lensed arcs in 11 of these 17. These

strong and weak lensing signals will give an accurate measure of the

total mass and structure of the dark matter distribution that we will

subsequently compare with X-ray and Sunyaev Zeldovich Effect

observables. The broader applications of our project include 1} the

calibration of mass-temperature and mass-SZE scaling relations which

will be critical for the calibration of proposed dark energy

experiments, and 2} the low redshift baseline study of the demographics

of massive clusters to aid interpretation of future high redshift {z>1}

cluster samples. To complete the all-important high resolution imaging

component of our survey, we request deep WFPC2 observations of 20

clusters through the F606W filter, for which wide-field weak-lensing

data are already available from our Subaru imaging program. The

combination of deep WFPC2 and Subaru data for these 20 clusters will

enable us to achieve the science program approved by the Cycle 15 TAC.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS:

11020 - REacq(1,2,1) failed to RGA Hold (Gyro Control)

           The REacq(1,2,1) scheduled at 285/01:40:50 - 01:48:54 failed to RGA Hold

due to Search Radius Limit Exceeded Error on FGS-1. One 486 ESB "a05"

           (FGS Coarse Track failed-Search Radius Limit Exceeded was received at

           285/01:46:16. Additional ESB 1805(x2)(T2G_MOVING_TARGET_DETECTED) were

received. Pre-acquisition OBADs had (RSS) attitude correction values of

           29.38 and 14.40 arcseconds. OBAD/MAP had 3-axis (RSS) error value of

171.29 arcseconds. Prior guide star acquisition was successful.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                      SCHEDULED      SUCCESSFUL 

FGS GSacq               11                 11                 

FGS REacq               03                 02                       

OBAD with Maneuver 27                 27         

SIGNIFICANT EVENTS: (None)

-Lynn
____________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP Mission Operations Manager

CHAMP Flight Operations Team Manager
Lockheed Martin Mission Services (LMMS)

NASA GSFC PH#: 301-286-2876

"The Hubble Space Telescope is the astronomical observatory and key to unlocking the most cosmic mysteries of the past, present and future."    - 7/26/6