HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT      #4903

PERIOD COVERED: 5am August 5 - 5am August 6, 2009 (DOY 217/09:00z-218/09:00z)

OBSERVATIONS SCHEDULED

ACS/WFC3 11882

CCD Hot Pixel Annealing

All the data for this program is acquired using internal targets (lamps)

only, so all of the exposures should be taken during Earth occultation

time (but not during SAA passages). This program emulates the ACS

pre-flight ground calibration and post launch SMOV testing (program

8948), so that results from each epoch can be directly compared.

Extended Pixel Edge Response (EPER) and First Pixel Response (FPR) data

will be obtained over a range of signal levels for the Wide Field

Channel (WFC). The High Resolution Channel (HRC) visits have been

removed since it could not be repaired during SM4.

COS 11474

COS NUV Internal/External Wavelength Scales

Observe external radial velocity standard targets (preferably, though

not required, in CVZ) in TIME-TAG (FLASH=YES) mode with as many grating

and central wavelength combinations as feasible. The purpose is to

obtain zero-point offsets for the wavelength scale (internal wavecal

lamp scale to external standard wavelength scale) for all central

wavelengths. Following this determination, adjustments of the nominal

science target spectral range for each grating and central wavelength

combination will be made via SMS patchable constant for nominal OSM2

positions corresponding to each central wavelength. Subsequent to this

modification of the wavelength scale (and its verification in COS 15 -

program 11475), NUV science-related operations and wavelength-scale

dependent EROs can commence.

COS 11475

COS Internal NUV Wavelength Verification

This program will be executed after the uplink of the OSM2 position

updates derived from the determination of the wavelength-scale zero

points and desired spectral ranges for each grating in activity COS14

(program 11474 - COS NUV Internal/External Wavelength Scales). This

program will verify that the operational spectral ranges for each

grating, central wavelength, and FP-POS are those desired. Subsequent to

a successful verification, COS NUV ERO observations and NUV science can

be enabled. An internal wavelength calibration spectrum using the

default PtNe lamp (lamp 1) with each NUV grating at each central

wavelength setting and each FP-POS position will be obtained for the

verification. Additional exposures and waits between certain exposures

will be required to avoid - and to evaluate - mechanism drifts.

STIS/CCD 11844

CCD Dark Monitor Part 1

Monitor the darks for the STIS CCD.

STIS/CCD 11846

CCD Bias Monitor-Part 1

Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,

and 1x1 at gain = 4, to build up high-S/N superbiases and track the

evolution of hot columns.

WFC3 11552

Characterization of the WFC3 IR Grisms

Image displacement, spectral trace and dispersion, and throughput of the

IR G102 and G141 grisms will be verified. The HST flux standard GD 153

will be observed in a 5-point pattern in the IR field of view, which

will provide image displacement, spectral trace, and throughput

measurements as a function of location within the FOV. Similarly, the

planetary nebula PN HB12 will be observed in a 9-point pattern in the IR

field of view, which will provide dispersion measurements as a function

of FOV position.

WFC3 11808

WFC3 UVIS Bowtie Monitor

The UVIS detector was observed during ground testing to occasionally

exhibit flat field and dark variations with a bowtie pattern. These

variations are most significant as ~1% flat field (gain) variations

across the field of view. It is believed that this represents a state or

condition into which the detector can transition for reasons and under

circumstances which are not currently understood. It is also very

unlikely that most science observations will determine the state (bowtie

or no-bowtie) of the detector. Ground test data indicates that this

state is long lived (many hours to ~one day). Hysteresis or memory of

past light exposure is also associated with this state.

Recent evidence suggests that exposing the detector to ~200k to 500k

electrons may quench this state. This proposal obtains an internal flat

field sequence of three exposures: one at 10x full well with two at 0.5x

full well immediately before and after. Each exposure is 3x3 binned to

reduce the data volume required.

These visits should be scheduled 2x per day until further direction is

provided.

WFC3/UVI 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.

WFC3/UVI 11580

Watching Young Planetary Nebulae Grow: The Movie

The development of magneto-hydro gas dynamical models is the key to the

understanding of both the physics (processes) and astronomy (initial

conditions) of astrophysical nebulae of all sorts. The models are

reaching their highest degree of accuracy when applied to and compared

against pre Planetary Nebulae (pPNe) thanks to the simplicity, relative

lack of extinction, and the detail of the imaging and kinematic data

that have bcome available for these objects. The primary barrier to

progress is inadequate kinematic data of pPNe against which the

predictions models can be tested. Unlike PNe, pPNe do not emit emission

lines for detailed Doppler measurements. Therefore it is essential to

find another way to monitor the morphological evolution.

Only HST can uncover the dynamics of the growth patterns by subtracting

multi-epoch images spanning a decade or more. We have selected four pPNe

with highly collimated outflows in different evolutionary stages for

which high-quality first epoch images were obtained from 1996 to 2002.

All of them display regularly shaped thin rims, sharp edges, and

symmetric pairs of knots or bowshocks that are ideal for our purposes.

We will closely mimic many of the earlier exposures using ACS and to

monitor changes in structures. The morphology and its evolution will be

compared to 3-D MHD models with adaptive grids in order to build a far

clearer picture of the nuclear geometry which shaped the outflows and

constrained their propagation to the present. We shall also obtain R, J,

and H images for use with a 3-D dust radiative transfer code LELUYA to

model the dust distribution deep into the nuclear zones.

WFC3/UVI 11628

Globular Cluster Candidates for Hosting a Central Black Hole

We are continuing our study of the dynamical properties of globular

clusters and we propose to obtain surface brightness profiles for high

concentration clusters. Our results to date show that the distribution

of central surface brightness slopes do not conform to standard models.

This has important implications for how they form and evolve, and

suggest the possible presence of central intermediate-mass black holes.

From our previous archival proposals (AR-9542 and AR- 10315), we find

that many high concentration globular clusters do not have flat cores or

steep central cusps, instead they show weak cusps. Numerical simulations

suggest that clusters with weak cusps may harbor intermediate-mass black

holes and we have one confirmation of this connection with omega

Centauri. This cluster shows a shallow cusp in its surface brightness

profile, while kinematical measurements suggest the presence of a black

hole in its center. Our goal is to extend these studies to a sample

containing 85% of the Galactic globular clusters with concentrations

higher than 1.7 and look for objects departing from isothermal behavior.

The ACS globular cluster survey (GO-10775) provides enough objects to

have an excellent coverage of a wide range of galactic clusters, but it

contains only a couple of the ones with high concentration. The proposed

sample consists of clusters whose light profile can only be adequately

measured from space-based imaging. This would take us close to

completeness for the high concentration cases and therefore provide a

more complete list of candidates for containing a central black hole.

The dataset will also be combined with our existing kinematic

measurements and enhanced with future kinematic studies to perform

detailed dynamical modeling.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

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

HSTARS: (None)

COMPLETED OPS REQUEST:

18672-0 - Set up ACS memory monitor for ASIC single bit error counter @ 217/2010z

18671-0 - COS FUV High Voltage Update @ 217/2150z

COMPLETED OPS NOTES: (None)

                       SCHEDULED      SUCCESSFUL

FGS GSAcq               09                 09              

FGS REAcq               10                 10            

OBAD with Maneuver 10                 10           

SIGNIFICANT EVENTS: (None)