Status Report

NASA Hubble Space Telescope Daily Report #4951

By SpaceRef Editor
October 19, 2009
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Continuing to Collect World Class Science

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


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 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 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 3×3 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)

FGS GSAcq 07 07
FGS REAcq 10 10
OBAD with Maneuver 05 05


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