Status Report

NASA Hubble Space Telescope Daily Report #4355

By SpaceRef Editor
May 4, 2007
Filed under , ,
NASA Hubble Space Telescope Daily Report #4355
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Notice: For the foreseeable future, the daily reports may contain apparent discrepancies between some proposal descriptions and the listed instrument usage. This is due to the conversion of previously approved ACS WFC or HRC observations into WFPC2, or NICMOS observations subsequent to the loss of ACS CCD science capability in late January.

HUBBLE SPACE TELESCOPE DAILY REPORT # 4355
– Continuing to collect World Class Science

DAILY REPORT # 4355

PERIOD COVERED: UT May 03, 2007 (DOY 123)

OBSERVATIONS SCHEDULED

WFPC2 10800

Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have relatively fragile test particles which can be used as tracers of the early dynamical evolution of the outer Solar System. We propose to continue a Snapshot program using the ACS/HRC that has a demonstrated discovery potential an order of magnitude higher than the HST observations that have already discovered the majority of known transneptunian binaries. With this continuation we seek to reach the original goals of this project: to accumulate a sufficiently large sample in each of the distinct populations collected in the Kuiper Belt to be able to measure, with statistical significance, how the fraction of binaries varies as a function of their particular dynamical paths into the Kuiper Belt. Today’s Kuiper Belt bears the imprints of the final stages of giant-planet building and migration; binaries may offer some of the best preserved evidence of that long-ago era.

WFPC2 10877

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for supernovae {SNe}, most notably our Lick Observatory Supernova Search {LOSS}, have found hundreds of SNe, many of them in quite nearby galaxies {cz < 4000 km/s}. Most of the objects were discovered before maximum brightness, and have follow-up photometry and spectroscopy; they include some of the best-studied SNe to date. We propose to conduct a snapshot imaging survey of the sites of some of these nearby objects, to obtain late-time photometry that {through the shape of the light and color curves} will help reveal the origin of their lingering energy. The images will also provide high-resolution information on the local environments of SNe that are far superior to what we can procure from the ground. For example, we will obtain color-color and color-magnitude diagrams of stars in these SN sites, to determine the SN progenitor masses and constraints on the reddening. Recovery of the SNe in the new HST images will also allow us to actually pinpoint their progenitor stars in cases where pre- explosion images exist in the HST archive. This proposal is an extension of our successful Cycle 13 snapshot survey with ACS. It is complementary to our Cycle 15 archival proposal, which is a continuation of our long-standing program to use existing HST images to glean information about SN environments.

WFPC2 10910

HST / Chandra Monitoring of a Dramatic Flare in the M87 Jet

As the nearest galaxy with an optical jet, M87 affords an unparalleled opportunity to study extragalactic jet phenomena at the highest resolution. During 2002, HST and Chandra monitoring of the M87 jet detected a dramatic flare in knot HST-1 located ~1″ from the nucleus. Its optical brightness eventually increased seventy-fold and peaked in 2005; the X- rays show a similarly dramatic outburst. In both bands HST-1 is still extremely bright and greatly outshines the galaxy nucleus. To our knowledge this is the first incidence of an optical or X-ray outburst from a jet region which is spatially distinct from the core source — this presents an unprecedented opportunity to study the processes responsible for non- thermal variability and the X-ray emission. We propose five epochs of HST/ACS flux monitoring during Cycle 15, as well as seven epochs of Chandra/ACIS observation {5ksec each, five Chandra epochs contemporary with HST}. At two of the HST/ACS epochs we also gather spectral information and map the magnetic field structure. The results of this investigation are of key importance not only for understanding the nature of the X-ray emission of the M87 jet, but also for understanding flares in blazar jets, which are highly variable, but where we have never before been able to resolve the flaring region in the optical or X-rays. These observations will allow us to test synchrotron emission models for the X- ray outburst, constrain particle acceleration and loss timescales, and study the jet dynamics associated with this flaring component.

WFPC2 10880

The host galaxies of QSO2s: AGN feeding and evolution at high luminosities

Now that the presence of supermassive black holes in the nuclei of galaxies is a well established fact, other questions related to the AGN phenomena still have to be answered. Problems of particular interest are how the AGN gets fed, how the black hole evolves and how the evolution of the black hole is related to the evolution of the galaxy bulge. Here we propose to address some of these issues using ACS/WFC + F775W snapshot images of 73 QSO2s with redshifts in the range 0.3NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration – CR Persistence Part 5

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=3Ddate/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 10808

Morphologies of spectroscopically-confirmed “red and dead” galaxies at z~2.5

Using a combination of wide-field near-infrared imaging and very deep follow-up near-infrared spectroscopy we have identified a population of massive “red and dead” galaxies at z~2.5. The galaxies lack emission lines and have strong Balmer/4000 Angstrom breaks, demonstrating directly that they have evolved stellar populations. These objects are very likely progenitors of massive ellipticals today and may be descendants of the first generation of galaxies. We propose to image 10 of these objects with the NIC2 camera to determine their morphologies. The goals are to 1} determine whether they have the sizes of present-day early-types or are more compact, as predicted by models, 2} determine the morphology, using visual classification and quantitative methods, and 3} constrain the evolution of the Kormendy relation from z~2.5 to the present. These observations will show whether the oldest and most massive galaxies at z~2.5 were already fully formed or still in the process of assembly.

NIC3 10839

The NICMOS Polarimetric Calibration

Recently, it has been shown that NICMOS possesses an instrumental polarization at a level of 1.2%. This completely inhibits the data reduction in a number of previous GO programs, and hampers the ability of the instrument to perform high accuracy polarimetry. In all, 90 orbits of HST data are affected, with potentially many more in Cycle 15. We propose to obtain high signal to noise observations of three polarimetric standards at the cardinal roll angles of the NICMOS polarizers for both NIC1 and NIC2. These observations are designed to fully characterize the instrumental polarization in order for NICMOS to reach its full potential by enabling high accuracy polarimetry of sources with polarizations around 1%. The residual polarization will also be determined as a function of position and spectral energy distribution. Our group will rapidly turn around the required data products and produce reports and software for the accurate representation of the instrumental polarization. These items will be presented to STScI and for dissemination among the wider astronomical community.

NIC3 11080

Exploring the Scaling Laws of Star Formation

As a variety of surveys of the local and distant Universe are approaching a full census of galaxy populations, our attention needs to turn towards understanding and quantifying the physical mechanisms that trigger and regulate the large-scale star formation rates {SFRs} in galaxies.

WFPC2 10845

HUNTING FOR OPTICAL COMPANIONS TO BINARY MILLISECOND PULSARS IN TERZAN 5 AND NGC6266

We propose deep WFPC2 and NICMOS observations to search for optical companions to binary millisecond pulsar {MSPs} in two Globular Clusters {GCs}: Terzan 5 and NGC6266. Terzan 5 has the largest MSP population of any GC: 33 MSP {17 in binary systems} have been discovered up to now in this stellar system. NGC6266 ranks fifth among the GC for wealth of MSPs but it is the only one in which all the {six} detected MSPs are in binary systems. Only 5 optical counterparts to binary MSP companions are known in GCs {two of them have been discovered by our group}: hence even the addition of a few new identifications are crucial to investigate the variety of processes occurring in binary MSPs in dense environment. The observations proposed here would easily double/triple the existing sample of known MSP companions, allowing the first meaningful study of the phenomena which drive the formation and evolution of these exotic systems. Moreover, since most of binary MSP in GC are formed via stellar interactions in the high density regions of the cluster, the determination of the nature of the companion and the incidence of this collisionally induced population have a significant impact on our knowledge of the cluster dynamics. Even more interesting, the study of the optical companions to NSs in a GC allows to derive tighter constraints {than those obtainable for NS binaries in the galactic field} on the properties {mass, orbital inclination and so on} of the compation star. This has, in turn, an intrisic importance for fundamental physics since it offers the opportunity of measuring the mass of the NS and hence to put constraints to the equation of state of matter at nuclear equilibrium density.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)

HSTARS: 10798 – GSacq (2,3,2) failed to RGA control

During LOS the GSacq (2,3,2) scheduled at 123/22:31:35
failed. At The Map at 23:20:21 showed errors of v1=3D 431.20, V2=3D708.51,
V3=3D926.65 and RSS=3D 1243.62.

AOS (23:19:01) we observed stop flags QF2STOPF and QSTOP for
FGS 2.

The REacq (2,3,2) at 124/00:04:19 also failed during LOS with
stop flags on FGS 2.

COMPLETED OPS REQUEST: 18058-1 – MSS/CSSGyro2 KF Initialization Convergence Testing for SMS 120
(Test # 36 & 9)
18059-1 – MSS/CSS KF Add/Removal of Gyro1 Input Testing for SMS 120
(Test # 28) 18061-1 – MSS KF Adding Gyro1 Convergence Testing for SMS 120 (Test #
22) 18054-0 – Preview KF Sun Vector Data via Telemetry Diags 18067-1 – PCS KF OOT Support

18068-1 – PCS KF OOT Support

COMPLETED OPS NOTES: (None)

                      SCHEDULED      SUCCESSFUL

FGS GSacq              10                 09
FGS REacq              03                 02

OBAD with Maneuver     27                 27

SIGNIFICANT EVENTS:

Evaluation of Universal Kalman Filter performance continued. Multiple text segments were executed, all of them successfully. Details follow.

Background Kalman Filter Operation Flash Report for day 123

The KF was halted at 123/16:15 (OR 18061-1). The filter was restarted at 123/16:16 during orbit day and during an F2G guiding interval. The filter was activated with only the MSS enabled. The Gyro1 sensor input was added to the converged KF at 123/16:28 during orbit day, in an M2G guiding period with the vehicle inertially fixed and during a slow changing B-field. All UKF parameters showed nominal operation. The test was an MSS/Gyro1 test case with the Gyro1 input added to an already converged filter with the vehicle inertially fixed and during a slow changing B-field (M_G1_RNS, Test #22).

The Gyro input was removed at 123/16:39 and the CSS sensor input re-enabled at 123/16:50 to reconfigure the KF back to its default MSS/CSS input state. The activity above used the slot 1 TMDIAG at 123/16:24. The slot 1 TMDIAG was reset to monitor the V2 component of the KF estimated sun vector at 123/16:52.

The Gyro1 sensor input was added to the an already converged KF at 123/18:15. The MSS and CSS sensor inputs were enabled. The Gyro1 sensor input was added during an M2G guiding period during orbit day, during a vehicle slew and during a slow changing B-field. All UKF parameters showed nominal operation. The test was an MSS/CSS test case with the Gyro1 sensor input added during a vehicle slew and a slow changing B-field (MC_G1_RVS, Test #28).

The MSS/CSS default KF configuration was restored at 123/19:11. The activity above used the slot 1 TMDIAG at 123/18:15. The slot 1 TMDIAG was reset to monitor the V2 component of the KF estimated sun vector at 123/19:24. The KF was halted at 123/20:05. The filter was restarted at 123/20:04 during an M2G guiding period, during orbit day, during a vehicle slew and during a slow changing B-field. All UKF parameters showed nominal operation. The test was an MSS/CSS/Gyro2 Initialization test case during a vehicle slew and during a slow changing B-field (MC_G1_IVS, Test #36).

The MSS/CSS default configuration was restored at 123/20:17. The filter was planned to be restarted in the default configuration at 20:15 to execute an additional test (M_C_IVP, Test #9). This test is an initialization test with the MSS and CSS sensor inputs enabled at orbit day, during a vehicle slew immediately prior to EON. However, due to communication issues the test was not executed at the time required to capture the penumbra. This test will be rescheduled.

The tests above complete the KF testing for the week of the 120 SMS.

SpaceRef staff editor.