NASA Hubble Space Telescope Daily Report #4354
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 # 4354
– Continuing to collect World Class Science
PERIOD COVERED: UT May 02, 2007 (DOY 122)
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 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 0.3< z< 0.4. These observations will be combined with similar archival data of QSO1s and ground based data of Seyfert and normal galaxies. First, we will intestigate whether interactions are the most important feeding mechanism in high luminosity AGNs. This will be done in a quantitative way, comparing the asymmetry indices of QSO2 hosts with those of lower luminosity AGNs and normal galaxies. Second, we will do a detailed study of the morphology of the host galaxies of both QSO types, to determine if they are similar, or if there is an evolutionary trend from QSO2s to QSO1s. The results from this project will represent an important step in the understanding of AGN evolution, and may also introduce a substantial modification to the Unified Model.
NIC1/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=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 10847
Coronagraphic Polarimetry of HST-Resolved Debris Disks
We propose to take full advantage of the recently commissioned coronagraphic polarimetry modes of ACS and NICMOS to obtain imaging polarimetry of circumstellar debris disks that were imaged previously by the HST coronagraphs, but without the polarizers. It is well established that stars form in gas-rich protostellar disks, and that the planets of our solar system formed from a circum-solar disk. However, the connection between the circumstellar disks that we observe around other stars and the processes of planet formation is still very uncertain. Mid-IR spectral studies have suggested that disk grains are growing in the environments of young stellar objects during the putative planet-formation epoch. Furthermore, structures revealed in well resolved images of circumstellar disks suggest gravitational influences on the disks from co-orbital bodies of planetary mass. Unfortunately, existing imaging data provides only rudimentary information abou the disk grains and their environments. Our proposed observations, which can be obtained only with HST, will enable us to quantitatively determine the sizes of the grains and optical depths as functions of their location within the disks {i.e., detailed tomography}. Armed with these well-determine physical and geometrical systemic parameters, we will develop a set of self- consistent models of disk structures to investigate possible interactions between unseen planets and the disks from which they formed. Our results will also calibrate models of the thermal emission from these disks, that will in turn enable us to infer the properties of other debris disks that cannot be spatially resolved with current or planned instruments and telescopes.
NIC2 10849
Imaging Scattered Light from Debris Disks Discovered by the Spitzer Space Telescope around 21 Sun-like Stars
We propose to use the high-contrast capability of the NICMOS coronagraph to image a sample of newly discovered circumstellar disks associated with Sun-like stars. These systems were identified by their strong thermal infrared {IR} emission with the Spitzer Space Telescope as part of the Spitzer Legacy Science program titled “The Formation and Evolution of Planetary Systems” {FEPS, P.I.: M.Meyer}. Modeling of the thermal excess emission from the spectral energy distributions alone cannot distinguish between narrowly confined high-opacity disks and broadly distributed, low-opacity disks. By resolving light scattered by the circumstellar material, our proposed NICMOS observations can break this degeneracy, thus revealing the conditions under which planet formation processes are occuring or have occured. For three of our IR-excess stars that have known radial-velocity planets, resolved imaging of the circumstellar debris disks may further offer an unprecedented view of planet-disk interactions in an extrasolar planetary system. Even non-detections of the light scattered by the circumstellar material will place strong constraints on the disk geometries, ruling out disk models with high optical depth. Unlike previous disk imaging programs, our program contains a well-defined sample of ~1 solar mass stars covering a range of ages from 3 Myr to 3 Gyr, thus allowing us to study the evolution of disks from primordial to debris for the first time. The results from our program will greatly improve our understanding of the architecture of debris disks around Sun-like stars, and will create a morphological context for the existence of our own solar system. This proposal is for a continuation of an approved Cycle 14 program {GO/10527, P.I.: D. Hines}.
NIC2 10802
SHOES-Supernovae, HO, for the Equation of State of Dark energy
The present uncertainty in the value of the Hubble constant {resulting in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at redshifts exceeding 1 are now the leading obstacles to determining the nature of dark energy. We propose a single, integrated set of observations for Cycle 15 that will provide a 40% improvement in constraints on dark energy. This program will observe known Cepheids in six reliable hosts of Type Ia supernovae with NICMOS, reducing the uncertainty in H_0 by a factor of two because of the smaller dispersion along the instability strip, the diminished extinction, and the weaker metallicity dependence in the infrared. In parallel with ACS, at the same time the NICMOS observations are underway, we will discover and follow a sample of Type Ia supernovae at z > 1. Together, these measurements, along with prior constraints from WMAP, will provide a great improvement in HST’s ability to distinguish between a static, cosmological constant and dynamical dark energy. The Hubble Space Telescope is the only instrument in the world that can make these IR measurements of Cepheids beyond the Local Group, and it is the only telescope in the world that can be used to find and follow supernovae at z > 1. Our program exploits both of these unique capabilities of HST to learn more about one of the greatest mysteries in science.
NIC3 10792
Quasars at Redshift z=6 and Early Star Formation History
We propose to observe four high-redshift quasars {z=6} in the NIR in order to estimate relative Fe/Mg abundances and the central black hole mass. The results of this study will critically constrain models of joint quasar and galaxy formation, early star formation, and the growth of supermassive black holes. Different time scales and yields for alpha-elements {like O or Mg} and for iron result into an iron enrichment delay of ~0.3 to 0.6 Gyr. Hence, despite the well-known complexity of the FeII emission line spectrum, the ratio iron/alpha – element is a potentially useful cosmological clock. The central black hole mass will be estimated based on a recently revised back hole mass – luminosity relationship. The time delay of the iron enrichment and the time required to form a supermassive black hole {logM>8 Msol, tau ~0.5Gyr} as evidenced by quasar activity will be used to date the beginning of the first intense star formation, marking the formation of the first massive galaxies that host luminous quasars, and to constrain the epoch when supermassive black holes start to grow by accretion.
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:
10797 – REacq(1,2,1) failed to RGA control
The REacq(1,2,1) scheduled at 123/01:24:40 failed to RGA contro1. At 01:28:330 Stop flags QF1STOPF and QSTOP were received for FGS 1. OBAD1 showed errors of V1=-31.98, V2=-793.32, V3= -21.99, and RSS=794.27. OBAD2 showed errors of V1=1.35, V2= -3.78, V3=1.32, and RSS= 4.22. The map at 01:32:58 showed errors of V1=-2.89, V2=12.54, V3=-4.03, and RSS=13.49. REACQ(1,2,1) at 03:00:31 also failed with QF1STOPF and QSTOP flags received at 03:04:14. OBAD prior ro REACQ had RSS error of 14.97 arcseconds
COMPLETED OPS REQUEST:
18062-0 – MSS KF Initialization Convergence Testing for SMS 120 (Test # 1)
18066-3 – PCS KF OOT Support, 122/18:15
18061-1 – MSS KF Adding Gyro1 Convergence Testing for SMS 120 (Test # 24)
18054-0 – Preview KF Sun Vector Data via Telemetry Diags, Generic
18062-0 – MSS KF Initialization Convergence Testing for SMS 120 (Test #4)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL FGS GSacq 10 10 FGS REacq 05 03 OBAD with Maneuver 30 30
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 122. The KF was halted at 122/11:26 (OR 18062-0) during orbit day and during a T2G guiding interval. The filter was restarted at 122/11:27 with the CCS input disabled, during an M2G period, during a vehicle slew and during a fast changing B-field. The filter was activated with only the MSS enabled. All UKF parameters showed nominal operation. The test was an MSS Initialization test case during a vehicle slew and during a fast changing B-field (M_0_IVF, Test #1). The MSS/CSS default KF configuration was restored at 122/12:11.
The KF was halted at 122/17:48 during orbit day with no vehicle slew and during an F2G guiding interval. The filter was restarted at 122/17:50 with the CSS input disabled. The Gyro1 sensor input was added to the converged KF at 122/17:59 during orbit day and with no ongoing vehicle maneuver. The Gyro1 sensor input was then removed at 122/18:20 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/Gyro1 test case with the Gyro1 input removed from an already converged KF with the MSS and Gyro1 sensor input enabled, during a vehicle maneuver and during a slow changing B-field (M_G1_HVS, Test #24).
The CSS sensor input was re-enabled at 122/19:04 to restore the default MSS/CSS configuration of the filter. The KF estimated sun vector TMDIAG slot 1 was overwritten at 122/17:59 and restored at 122/19:06. The KF was halted at 122/19:56 (OR 18062-0) during orbit day and during an M2G guiding interval. The filter was restarted at 122/19:58 during orbit day with no ongoing vehicle maneuver and during a slow changing B-field. All UKF parameters showed nominal operation. The test was an MSS Only Initialization with the vehicle inertially fixed and during a slow changing B-field (M_0_INS, Test #4). The KF was halted, the CCS sensor input was re-enabled and the KF restarted at 122/20:25 to reconfigure the KF to its default configuration. The test above completed testing for day 122.
