HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT      #4951

 

PERIOD COVERED: 5am October 14 - 5am October 15, 2009 (DOY 287/09:00z-288/09:00z)

 

OBSERVATIONS SCHEDULED

 

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.

 

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.

 

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.

 

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.

 

STIS/CCD 11844

 

CCD Dark Monitor Part 1

 

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

 

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.

 

WFC3/IR 11719

 

A Calibration Database for Stellar Models of Asymptotic Giant Branch

Stars

 

Studies of galaxy formation and evolution rely increasingly on the

interpretation and modeling of near-infrared observations. At these

wavelengths, the brightest stars are intermediate mass asymptotic giant

branch (AGB) stars. These stars can contribute nearly 50% of the

integrated luminosity at near infrared and even optical wavelengths,

particularly for the younger stellar populations characteristic of

high-redshift galaxies (z>1). AGB stars are also significant sources of

dust and heavy elements. Accurate modeling of AGB stars is therefore of

the utmost importance.

 

The primary limitation facing current models is the lack of useful

calibration data. Current models are tuned to match the properties of

the AGB population in the Magellanic Clouds, and thus have only been

calibrated in a very narrow range of sub-solar metallicities.

Preliminary observations already suggest that the models are

overestimating AGB lifetimes by factors of 2-3 at lower metallicities.

At higher (solar) metallicities, there are no appropriate observations

for calibrating the models.

 

We propose a WFC3/IR SNAP survey of nearby galaxies to create a large

database of AGB populations spanning the full range of metallicities and

star formation histories. Because of their intrinsically red colors and

dusty circumstellar envelopes, tracking the numbers and bolometric

fluxes of AGB stars requires the NIR observations we propose here. The

resulting observations of nearby galaxies with deep ACS imaging offer

the opportunity to obtain large (100-1000's) complete samples of AGB

stars at a single distance, in systems with well-constrained star

formation histories and metallicities.

 

WFC3/IR/UV 11835

 

The Multi-faceted X-ray Activity of Low-redshift Active Galaxies

 

We propose ACIS-I observations of Chandra-unobserved low-redshift 3CRR

active galaxies and their environments. The data will complete Chandra

observations of 3CRR at z < 0.1, making the sample useful for

statistical studies. Only Chandra can resolve the multiple components of

these sources, as is needed for an improved understanding of source

physics and gas heating. The imaging and spectroscopy of cores, jets,

hot spots, and atmospheres will be of permanent legacy value. We will

use the data to investigate particle acceleration, interactions between

radio plasma and the ISM and IGM, the emission mechanisms of hot spots,

and AGN fueling. Comparison with our complete Spitzer coverage and HST

images will aid interpretation. The dataset will be made public

immediately.

 

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 11615

 

Hunting for Optical Companions to Binary MSPs in Globular Clusters

 

Here we present a proposal which exploits the re-newed potential of HST

after the Service Mission 4 for probing the population of binary

Millisecond Pulsars (MSPs) in Globular Clusters. In particular we intend

to: (1) extend the search for optical counterparts in Terzan 5, by

pushing the performance of the WFC3 IR channel to sample the entire MS

extension down to M=0.1 Mo; (2) perform a deep multi-band search of MSP

companions with the WFC3, in 3 clusters (namely NGC6440, M28 and M5),

where recent radio observations have found particularly interesting

objects; (3) derive an accurate radial velocity (with STIS) of the

puzzling optical companion COM6266B recently discovered by our group, to

firmly assess its cluster membership. This program is the result of a

large collaboration among the three major groups (lead by Freire, Ransom

and Possenti) which are performing extensive MSP search in GCs in the

radio bands, and our group which has a large experience in performing

accurate stellar photometry in crowded environments. This collaboration

has produced a number of outstanding discoveries. In fact, three of the

6 optical counterparts to binary MSP companions known to date in GCs

have been discovered by our group. The observations here proposed would

easily double/triple the existing sample of known MSP companions,

allowing the first meaningful approach to the study of the formation,

evolution and recycling process of pulsar in GCs. Moreover, since most

of binary MSPs in GCs are thought to form via stellar interactions in

the high density core regions, the determination of the nature of the

companion and the incidence of this collisionally-induced population has

a significant impact on our knowledge of the cluster dynamics. Even more

interesting, the study of the optical companions to NSs in GCs allows

one to derive tighter constraints (than those obtainable for NS binaries

in the Galactic field) on the system properties. This has, in turn, an

intrisic importance for fundamental physics, since it offers the

opportunity of measuring the mass of the NS and hence constraining the

equation of state of matter at the nuclear equilibrium density.

 

WFC3/UVIS 11905

 

WFC3 UVIS CCD Daily Monitor

 

The behavior of the WFC3 UVIS CCD will be monitored daily with a set of

full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K

subarray biases are acquired at less frequent intervals throughout the

cycle to support subarray science observations. The internals from this

proposal, along with those from the anneal procedure (Proposal 11909),

will be used to generate the necessary superbias and superdark reference

files for the calibration pipeline (CDBS).

 

WFC3/UVIS 11908

 

Cycle 17: UVIS Bowtie Monitor

 

Ground testing revealed an intermittent hysteresis type effect in the

UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.

Initially found via an unexpected bowtie-shaped feature in flatfield

ratios, subsequent lab tests on similar e2v devices have since shown

that it is also present as simply an overall offset across the entire

CCD, i.e., a QE offset without any discernable pattern. These lab tests

have further revealed that overexposing the detector to count levels

several times full well fills the traps and effectively neutralizes the

bowtie. Each visit in this proposal acquires a set of three 3x3 binned

internal flatfields: the first unsaturated image will be used to detect

any bowtie, the second, highly exposed image will neutralize the bowtie

if it is present, and the final image will allow for verification that

the bowtie is gone.

 

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: (None)

 

COMPLETED OPS NOTES: (None)

 

                       SCHEDULED      SUCCESSFUL

FGS GSAcq               07                 07                    

FGS REAcq               10                 10                

OBAD with Maneuver 05                 05               

 

SIGNIFICANT EVENTS: (None)