Results for "W. B. McKinnon P. M. Schenk"

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Modeling glacial flow on and onto Pluto's Sputnik PlanitiaJun 18 2016Jul 26 2018Observations of Pluto's surface made by the New Horizons spacecraft indicates present-day nitrogen ice glaciation in and around the basin known as Sputnik Planum. Motivated by these observations, we have developed an evolutionary glacial flow model of ... More
Modeling glacial flow on and onto Pluto's Sputnik PlanumJun 18 2016Observations of Pluto's surface made by the New Horizons spacecraft indicates present-day nitrogen ice glaciation in and around the basin known as Sputnik Planum. Motivated by these observations, we have developed an evolutionary glacial flow model of ... More
Impact Craters on Pluto and Charon Indicate a Deficit of Small Kuiper Belt ObjectsFeb 27 2019The flyby of Pluto and Charon by the New Horizons spacecraft provided high-resolution images of cratered surfaces embedded in the Kuiper belt, an extensive region of bodies orbiting beyond Neptune. Impact craters on Pluto and Charon were formed by collisions ... More
Great Expectations: Plans and Predictions for New Horizons Encounter with Kuiper Belt Object 2014 MU69 ('Ultima Thule')Aug 06 2018The New Horizons encounter with the cold classical Kuiper Belt object (KBO) 2014 MU69 (informally named 'Ultima Thule,' hereafter Ultima) on 1 January 2019 will be the first time a spacecraft has ever closely observed one of the free-orbiting small denizens ... More
A Search for Temporal Changes on Pluto and CharonNov 07 2017A search for temporal changes on Pluto and Charon was motivated by (1) the discovery of young surfaces in the Pluto system that imply ongoing or recent geologic activity, (2) the detection of active plumes on Triton during the Voyager 2 flyby, and (3) ... More
Internal-state thermometry by depletion spectroscopy in a cold guided beam of formaldehydeOct 17 2007We present measurements of the internal state distribution of electrostatically guided formaldehyde. Upon excitation with continuous tunable ultraviolet laser light the molecules dissociate, leading to a decrease in the molecular flux. The population ... More
The Small Satellites of Pluto as Observed by New HorizonsApr 18 2016The New Horizons mission has provided resolved measurements of Pluto's moons Styx, Nix, Kerberos, and Hydra. All four are small, with equivalent spherical diameters of $\approx$40 km for Nix and Hydra and ~10 km for Styx and Kerberos. They are also highly ... More
Formation of Charon's Red Poles From Seasonally Cold-Trapped VolatilesMar 09 2019A unique feature of Pluto's large satellite Charon is its dark red northern polar cap. Similar colours on Pluto's surface have been attributed to organic macromolecules produced by energetic radiation processing of hydrocarbons. The polar location of ... More
Reorientation of Sputnik Planitia implies a Subsurface Ocean on PlutoMar 13 2019The deep nitrogen-covered Sputnik Planitia (SP; informal name) basin on Pluto is located very close to the longitude of Pluto's tidal axis[1] and may be an impact feature [2], by analogy with other large basins in the solar system[3,4]. Reorientation[5-7] ... More
Triton's surface age and impactor population revisited in light of Kuiper Belt fluxes: Evidence for small Kuiper Belt objects and recent geological activityOct 24 1999Neptune's largest satellite, Triton, is one of the most fascinating and enigmatic bodies in the solar system. Among its numerous interesting traits, Triton appears to have far fewer craters than would be expected if its surface was primordial. Here we ... More
The Geology of Pluto and Charon Through the Eyes of New HorizonsApr 19 2016NASA's New Horizons spacecraft has revealed the complex geology of Pluto and Charon. Pluto's encounter hemisphere shows ongoing surface geological activity centered on a vast basin containing a thick layer of volatile ices that appears to be involved ... More
Convection in a volatile nitrogen-ice-rich layer drives Pluto's geological vigorMar 13 2019The vast, deep, volatile-ice-filled basin informally named Sputnik Planum is central to Pluto's geological activity[1,2]. Composed of molecular nitrogen, methane, and carbon monoxide ices[3], but dominated by N2-ice, this ice layer is organized into cells ... More
Optimization-based Islanding of Power Networks using Piecewise Linear AC Power FlowOct 24 2013Oct 25 2013In this paper, a flexible optimization-based framework for intentional islanding is presented. The decision is made of which transmission lines to switch in order to split the network while minimizing disruption, the amount of load shed, or grouping coherent ... More
Electrostatic extraction of cold molecules from a cryogenic reservoirJun 16 2008Jan 23 2009We present a method which delivers a continuous, high-density beam of slow and internally cold polar molecules. In our source, warm molecules are first cooled by collisions with a cryogenic helium buffer gas. Cold molecules are then extracted by means ... More
Density functional theory for a model quantum dot: Beyond the local-density approximationSep 17 2010We study both static and transport properties of model quantum dots, employing density functional theory as well as (numerically) exact methods. For the lattice model under consideration the accuracy of the local-density approximation generally is poor. ... More
The nitrogen cycles on Pluto over seasonal and astronomical timescalesApr 06 2018Pluto's landscape is shaped by the cycles of the volatile ices covering its surface. In particular, the Sputnik Planitia (SP) ice sheet displays a large diversity of terrains, with bright and dark plains, pits, topographic depressions and evidences of ... More
The Expanded Very Large ArraySep 08 2009In almost 30 years of operation, the Very Large Array (VLA) has proved to be a remarkably flexible and productive radio telescope. However, the basic capabilities of the VLA have changed little since it was designed. A major expansion utilizing modern ... More
The LEAP of Pulsars in the Milky WayDec 24 2010The location of objects on the celestial sphere is a fundamental measurement in astronomy, and the distribution of these objects within the Milky Way is important for understanding their evolution as well as the large scale structure of the Galaxy. Here, ... More
Directional Statistics for Polarization Observations of Individual Pulses from Radio PulsarsDec 24 2010Radio polarimetry is a three-dimensional statistical problem. The three-dimensional aspect of the problem arises from the Stokes parameters Q, U, and V, which completely describe the polarization of electromagnetic radiation and conceptually define the ... More
The Analytical Solution to the Temporal Broadening of a Gaussian-Shaped Radio Pulse by Multipath Scattering from a Thin Screen in the Interstellar MediumApr 26 2014The radio pulse from a pulsar can be temporally broadened by multipath scattering in the interstellar medium and by instrumental effects within the radio telescope. The observed pulse shape is a convolution of the intrinsic one with the impulse responses ... More
The Pluto system: Initial results from its exploration by New HorizonsOct 26 2015The Pluto system was recently explored by NASA's New Horizons spacecraft, making closest approach on 14 July 2015. Pluto's surface displays diverse landforms, terrain ages, albedos, colors, and composition gradients. Evidence is found for a water-ice ... More
Search for the $Θ^+$ pentaquark in the reaction $γd \to p K^- K^+ n$Mar 14 2006May 04 2006A search for the \thp in the reaction $\gamma d \to pK^-K^+n$ was completed using the CLAS detector at Jefferson Lab. A study of the same reaction, published earlier, reported the observation of a narrow \thp resonance. The present experiment, with more ... More
The Transition between Nonorthogonal Polarization Modes in PSR B2016+28 at 1404 MHzJun 03 2003Polarization observations of the radio emission from PSR B2016+28 at 1404 MHz reveal properties that are consistent with two, very different, interpretations of the pulsar's viewing geometry. The pulsar's average polarization properties show a rapid change ... More
Orientation Angles of a Pulsar's Polarization VectorMar 17 2006A statistical model of the polarization of pulsar radio emission is used to derive the general statistics of a polarization vector's orientation angles. The theoretical distributions are compared with orientation angle histograms computed from single-pulse, ... More
Three-Dimensional Statistics of Radio PolarimetryJun 03 2003The measurement of radio polarization may be regarded as a three-dimensional statistical problem because the large photon densities at radio wavelengths allow the simultaneous detection of the three Stokes parameters which completely describe the radiation's ... More
Photometric and proper motion study of neglected open cluster NGC 2215May 20 2015Optical UBVRI photometric measurements using the Faulkes Telescope North were taken in early 2011 and combined with 2MASS JHK$_s$ and WISE infrared photometry as well as UCAC4 proper motion data in order to estimate the main parameters of the galactic ... More
Inflight Radiometric Calibration of New Horizons' Multispectral Visible Imaging Camera (MVIC)Mar 29 2016We discuss two semi-independent calibration techniques used to determine the in-flight radiometric calibration for the New Horizons' Multi-spectral Visible Imaging Camera (MVIC). The first calibration technique compares the observed stellar flux to modeled ... More
Topographic Constraints on the Origin of the Equatorial Ridge on IapetusApr 09 2014Saturn's moon Iapetus has an equatorial ridge system, which may be as high as 20 km, that may have formed by endogenic forces, such as tectonic and convective forces, or exogenic processes such as debris infall. We use high-resolution topographic data ... More
Polarization Patterns in Pulsar Radio EmissionOct 22 2008A variety of intriguing polarization patterns are created when polarization observations of the single pulses from radio pulsars are displayed in a two-dimensional projection of the Poincare sphere. In many pulsars, the projections produce two clusters ... More
On the Excess Dispersion in the Polarization Position Angle of Pulsar Radio EmissionJan 28 2004The polarization position angles (PA) of pulsar radio emission occupy a distribution that can be much wider than what is expected from the average linear polarization and the off-pulse instrumental noise. Contrary to our limited understanding of the emission ... More
Surface Compositions Across Pluto and CharonApr 18 2016The New Horizons spacecraft mapped colors and infrared spectra across the encounter hemispheres of Pluto and Charon. The volatile ices CH$_4$, CO, and N$_2$, that dominate Pluto's surface, have complicated spatial distributions resulting from sublimation, ... More
Overview of initial results from the reconnaissance flyby of a Kuiper Belt planetesimal: 2014 MU69Jan 09 2019Jan 24 2019The centerpiece objective of the NASA New Horizons first Kuiper Extended Mission (KEM-1) was the close flyby of the Kuiper Belt Object KBO) 2014 MU69, nicknamed Ultima Thule. On 1 Jan 2019 this flyby culminated, making the first close observations of ... More
Punctured Trellis-Coded ModulationJan 17 2013In classic trellis-coded modulation (TCM) signal constellations of twice the cardinality are applied when compared to an uncoded transmission enabling transmission of one bit of redundancy per PAM-symbol, i.e., rates of $\frac{K}{K+1}$ when $2^{K+1}$ ... More
Small crater populations on VestaMay 29 2013The NASA Dawn mission has extensively examined the surface of asteroid Vesta, the second most massive body in the main belt. The high quality of the gathered data provides us with an unique opportunity to determine the surface and internal properties ... More
Reduced Complexity Super-Trellis Decoding for Convolutionally Encoded Transmission Over ISI-ChannelsJul 19 2012Oct 04 2012In this paper we propose a matched encoding (ME) scheme for convolutionally encoded transmission over intersymbol interference (usually called ISI) channels. A novel trellis description enables to perform equalization and decoding jointly, i.e., enables ... More
An image-based search for pulsars among Fermi unassociated LAT sourcesDec 18 2017We describe an image-based method that uses two radio criteria, compactness and spectral index, to identify promising pulsar candidates among Fermi Large Area Telescope (LAT) unassociated sources. These criteria are applied to those radio sources from ... More
Matched Decoding for Punctured Convolutional Encoded Transmission Over ISI-ChannelsAug 01 2012Matched decoding is a technique that enables the efficient maximum-likelihood sequence estimation of convolutionally encoded PAM-transmission over ISI-channels. Recently, we have shown that the super-trellis of encoder and channel can be described with ... More
Constraining the Cratering Chronology of VestaJul 11 2014Vesta has a complex cratering history, with ancient terrains as well as recent large impacts that have led to regional resurfacing. Crater counts can help constrain the relative ages of different units on Vesta's surface, but converting those crater counts ... More
Polar-Coded ModulatonFeb 12 2013A framework is proposed that allows for a joint description and optimization of both binary polar coding and $2^m$-ary digital pulse-amplitude modulation (PAM) schemes such as multilevel coding (MLC) and bit-interleaved coded modulation (BICM). The conceptual ... More
Pulsar Astrometry at the Microarcsecond LevelSep 01 2005Determination of pulsar parallaxes and proper motions addresses fundamental astrophysical questions. We have recently finished a VLBI astrometry project to determine the proper motions and parallaxes of 27 pulsars, thereby doubling the total number of ... More
Topological symmetry breaking and the confinement of anyonsDec 11 2000We study topological symmetry breaking via the behaviour of Wilson and 't Hooft loop operators for the 2+1 dimenesional Abelian-Higgs model with Chern-Simons term. The topological linking of instantons, which are closed vortex loop configurations, give ... More
S2DFS: Analysis of temporal changes of drifting subpulsesSep 14 2009We introduce a new technique, called the Sliding Two-Dimensional Fluctuation Spectrum, used for detecting and characterising the temporal changes of drifting subpulses from radio pulsars. The method was tested using simulated data as well as archived ... More
Multilevel Polar-Coded ModulationJan 18 2013A framework is proposed that allows for a joint description and optimization of both binary polar coding and the multilevel coding (MLC) approach for $2^m$-ary digital pulse-amplitude modulation (PAM). The conceptual equivalence of polar coding and multilevel ... More
Secondary Analysis of Teaching Methods in Introductory Physics: a 50k-Student StudyMar 01 2016Oct 07 2016Physics education researchers have developed many evidence-based instructional strategies to enhance physics students' conceptual learning. These strategies have historically been tested using assessments such as the Force Concept Inventory (FCI) and ... More
Topological symmetry breaking and confinement of anyonsJun 02 1999We study the behaviour of Wilson and 't Hooft loop operators for the 2+1 dim. Abelian-Higgs model with Chern-Simons term. The phase of topological symmetry breaking where the vortex field condenses, found by Samuel for the model in the absence of the ... More
Mean radius and shape of Pluto and Charon from New Horizons imagesMar 02 2016Jun 22 2016Approach images taken by the LORRI imaging system during the New Horizons spacecraft encounter have been used to determine the mean radii and shapes of Pluto and Charon. The primary observations are limb locations derived using three independent approaches. ... More
Pluto's Haze as a Surface MaterialMar 09 2019Pluto's atmospheric haze settles out rapidly compared with geological timescales. It needs to be accounted for as a surface material, distinct from Pluto's icy bedrock and from the volatile ices that migrate via sublimation and condensation on seasonal ... More
Unscented External Force and Torque Estimation for QuadrotorsMar 09 2016Aug 02 2016In this paper, we describe an algorithm, based on the well-known Unscented Quaternion Estimator, to estimate external forces and torques acting on a quadrotor. This formulation uses a non-linear model for the quadrotor dynamics, naturally incorporates ... More
Learn Fast, Forget Slow: Safe Predictive Learning Control for Systems with Unknown and Changing Dynamics Performing Repetitive TasksOct 15 2018Apr 09 2019We present a control method for improved repetitive path following for a ground vehicle that is geared towards long-term operation where the operating conditions can change over time and are initially unknown. We use weighted Bayesian Linear Regression ... More
On the diversity of super-luminous supernovae: ejected mass as the dominant factorMar 11 2015Jan 13 2016We assemble a sample of 24 hydrogen-poor super-luminous supernovae (SLSNe). Parameterizing the light curve shape through rise and decline timescales shows that the two are highly correlated. Magnetar-powered models can reproduce the correlation, with ... More
Aspects of Polar-Coded ModulationNov 29 2012We consider the joint design of polar coding and higher-order modulation schemes for ever increased spectral efficiency. The close connection between the polar code construction and the multi-level coding approach is described in detail. Relations between ... More
Electronic states of Mn4+ ions in p-type GaNJun 09 2004The electronic states of manganese in p-type GaN are investigated using photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies. A series of sharp PL lines at 1.0 eV is observed in codoped GaN and attributed to the intra d-shell transition ... More
Next Generation Very Large Array Memo No. 5: Science Working Groups -- Project OverviewOct 21 2015We summarize the design, capabilities, and some of the priority science goals of a next generation Very Large Array (ngVLA). The ngVLA is an interferometric array with 10x larger effective collecting area and 10x higher spatial resolution than the current ... More
Towards Characterization of the Type IIP Supernova Progenitor Population: a Statistical Sample of Light Curves from Pan-STARRS1Apr 08 2014Feb 01 2015In recent years, wide-field sky surveys providing deep multi-band imaging have presented a new path for indirectly characterizing the progenitor populations of core-collapse supernovae (SN): systematic light curve studies. We assemble a set of 76 grizy-band ... More
Signatures of orbital loop currents in the spatially resolved local density of statesMar 06 2012Polarized neutron scattering measurements have suggested that intra-unit cell antiferromagnetism may be associated with the pseudogap phase. Assuming that loop current order is responsible for the observed magnetism, we calculate some signatures of such ... More
Optical investigation of electronic states of Mn4+ ions in p-type GaNDec 12 2004The electronic states of manganese in p-type GaN are investigated using photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies. A series of sharp PL lines at 1.0 eV is observed in codoped GaN and attributed to the intra d-shell transition ... More
Comment on the narrow structure reported by Amaryan et alApr 05 2012The CLAS Collaboration provides a comment on the physics interpretation of the results presented in a paper published by M. Amaryan et al. regarding the possible observation of a narrow structure in the mass spectrum of a photoproduction experiment.
Simulated Dynamics and Endohedral Relesase of Ne from Ne@C60 ClustersDec 29 2005Molecular Dynamics (MD) computer simulations are utilized to better understand the escape of neon from small (N=5) endohedral Ne@C60 clusters. Multiple runs at various temperatures are used to increase the reliability of our statistics. The cluster holds ... More
The PULSE@Parkes project: A new observing technique for long-term pulsar monitoringJul 28 2009The PULSE@Parkes project has been designed to monitor the rotation of radio pulsars over time spans of days to years. The observations are obtained using the Parkes 64-m and 12-m radio telescopes by Australian and international high school students. These ... More
On Time-Bounded Incompressibility of Compressible Strings and SequencesSep 17 2008Aug 11 2009For every total recursive time bound $t$, a constant fraction of all compressible (low Kolmogorov complexity) strings is $t$-bounded incompressible (high time-bounded Kolmogorov complexity); there are uncountably many infinite sequences of which every ... More
Tensor Correlations Measured in 3He(e,e'pp)nAug 18 2010We have measured the 3He(e,e'pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs using kinematic cuts and measured their relative and total momentum distributions. This ... More
Study of the gp-->etap reaction with the Crystal Ball detector at the Mainz Microtron(MAMI-C)Jul 05 2010Sep 25 2010The gp-->etap reaction has been measured with the Crystal Ball and TAPS multiphoton spectrometers in the energy range from the production threshold of 707 MeV to 1.4 GeV (1.49 =< W >= 1.87 GeV). Bremsstrahlung photons produced by the 1.5-GeV electron ... More
First Results from the La Silla-QUEST Supernova Survey and the Carnegie Supernova ProjectMar 24 2016The LaSilla/QUEST Variability Survey (LSQ) and the Carnegie Supernova Project (CSP II) are collaborating to discover and obtain photometric light curves for a large sample of low redshift (z < 0.1) Type Ia supernovae. The supernovae are discovered in ... More
Momentum sharing in imbalanced Fermi systemsNov 29 2014The atomic nucleus is composed of two different kinds of fermions, protons and neutrons. If the protons and neutrons did not interact, the Pauli exclusion principle would force the majority fermions (usually neutrons) to have a higher average momentum. ... More
The FUSE Spectrum of PG0804+761: A Study of Atomic and MolecularGas in the Lower Galactic Halo and BeyondOct 17 2000We present an analysis of interstellar and intergalactic absorption lines in the FUSE spectrum of the low-redshift quasar PG0804+761 (z=0.100) at intermediate resolution (FWHM=25 km/s) in the direction l=138.3, b=31.0. With a good signal-to-noise ratio ... More
Correlated spin-down rates and radio emission in PSR B1859+07Oct 15 2015We study the spin-down changes of PSR B1859$+$07 over a period of more than 28 years of radio observation. We identify that the time derivative of the rotational frequency ($\nu$) varies quasi-periodically with a period of $\sim$350 days, switching mainly ... More
Induced polarization of Λ(1116) in kaon electroproductionJun 16 2014We have measured the induced polarization of the ${\Lambda}(1116)$ in the reaction $ep\rightarrow e'K^+{\Lambda}$, detecting the scattered $e'$ and $K^+$ in the final state along with the proton from the decay $\Lambda\rightarrow p\pi^-$.The present study ... More
Dimension two condensates in the Gribov-Zwanziger theory in the Coulomb gaugeMar 10 2015Apr 16 2015We investigate the dimension two condensate $< {\bar \phi}^{ab}_i \phi^{ab}_i -{\bar \omega}^{ab}_i \omega^{ab}_i >$ within the Gribov-Zwanziger approach to Euclidean Yang-Mills theories in the Coulomb gauge, in both 3 and 4 dimensions. An explicit calculation ... More
Spin relaxation in $n$-type (111) GaAs quantum wellsAug 15 2010We investigate the spin relaxation limited by the D'yakonov-Perel' mechanism in $n$-type (111) GaAs quantum wells, by means of the kinetic spin Bloch equation approach. In (111) GaAs quantum wells, the in-plane effective magnetic field from the D'yakonov-Perel' ... More
The global random attractor for a class of stochastic porous media equationsOct 04 2010We prove new $L^2$-estimates and regularity results for generalized porous media equations "shifted by" a function-valued Wiener path. To include Wiener paths with merely first spatial (weak) derivates we introduce the notion of "$\zeta$-monotonicity" ... More
A Manifestly Gauge-Invariant Approach to Charged ParticlesOct 07 1996In this article we provide a manifestly gauge-invariant approach to charged particles. It involves (1) Green functions of gauge-invariant operators and (2) Feynman rules which do not depend on any kind of gauge-fixing condition. First, we provide a thorough ... More
Self-aligned fabrication process for silicon quantum computer devicesAug 20 2002Aug 28 2002We describe a fabrication process for devices with few quantum bits (qubits), which are suitable for proof-of-principle demonstrations of silicon-based quantum computation. The devices follow the Kane proposal to use the nuclear spins of 31P donors in ... More
Data reduction strategy of the Effelsberg-Bonn HI Survey (EBHIS)Sep 15 2009Since autumn 2008 a new L-band 7-Feed-Array receiver is used for an HI 21-cm line survey performed with the 100-m Effelsberg telescope. The survey will cover the whole northern hemisphere comprising both, the galactic and extragalactic sky in parallel. ... More
Cosmological Galaxy Evolution with Superbubble Feedback I: Realistic Galaxies with Moderate FeedbackMay 23 2015Sep 13 2015We present the first cosmological galaxy evolved using the modern smoothed particle hydrodynamics (SPH) code GASOLINE2 with superbubble feedback. We show that superbubble-driven galactic outflows powered by Type II supernovae alone can produce $\rm{L^*}$ ... More
Scaling Behaviors and Novel Creep Motion of Flux Lines under AC DrivingApr 27 2011We performed Langevin dynamics simulations for the \textit{ac} driven flux lines in a type II superconductor with random point-like pinning centers. Scaling properties of flux-line velocity with respect to instantaneous driving force of small frequency ... More
Voltage controlled spin precession in InAs quantum wellsNov 03 2010Dec 01 2010In this work we investigate spin diffusion in InAs quantum wells with the Rashba spin-orbit coupling modulated by a gate voltage. The gate voltage dependence of the spin diffusion under different temperatures is studied with all the scattering explicitly ... More
Coupled plasmon-phonon modes in a two-dimensional electron gas in the presence of Rashba effectApr 11 2003Elementary electronic excitation is studied theoretically for a 2DEG in the presence of spin orbit (SO) interaction induced by Rashba effect. In such a system, coupled plasmon-phonon excitation can be achieved via intra- and inter-SO electronic transitions. ... More
Magnetocapacitance effect in perovskite-superlattice based multiferroicsJun 14 2005We report the structural and magnetoelectrical properties of La$_{0.7}$Ca$_{0.3}$MnO$_3$/BaTiO$_3$ perovskite superlattices grown on (001)-oriented SrTiO$_3$ by the pulsed laser deposition technique. Magnetic hysteresis loops together with temperature ... More
Thin Fisher ZeroesMay 16 2001Biskup et al. [Phys. Rev. Lett. 84 (2000) 4794] have recently suggested that the loci of partition function zeroes can profitably be regarded as phase boundaries in the complex temperature or field planes. We obtain the Fisher zeroes for Ising and Potts ... More
Age and metallicity for six LMC clusters and their surrounding field populationApr 03 2000We investigate, on the basis of CCD Stroemgren photometry, the ages and metallicities of six LMC clusters together with their surrounding field population. The clusters and metallicities are: NGC1651 (in the range [Fe/H]=-0.65 dex to -0.41 dex), NGC1711 ... More
Red giant-disk encounters: Food for quasars?May 22 1996We explore the role that red giants might play in the central regions of Active Galactic Nuclei. Due to their large radii and the low binding energy of the stellar envelope, giants are vulnerable to envelope stripping from collisions with the accretion ... More
Super-luminous supernovae from PESSTOMay 06 2014Aug 04 2014We present optical spectra and light curves for three hydrogen-poor super-luminous supernovae followed by the Public ESO Spectroscopic Survey of Transient Objects (PESSTO). Time series spectroscopy from a few days after maximum light to 100 days later ... More
Coexistence and Competition of Isotropic Superconductivity and Itinerant AntiferromagnetismNov 25 2003Jan 06 2004This paper was withdrawn by the authors due to the belated discovery of a published paper showing similar results.
Absence of long-range Ni/Mn ordering in ferromagnetic La2NiMnO6 thin filmsJun 11 2007Epitaxial La2NiMnO6 thin films have been grown on (001)-oriented SrTiO3 using the PLD technique. The thin films are semiconducting and FM with a TC close to 270K, a coercive field of 920Oe, and a saturation magnetization of 5muB per f.u. TEM, conducted ... More
A comparative study of Type II-P and II-L supernova rise times as exemplified by the case of LSQ13cuwFeb 20 2015Aug 04 2015We report on our findings based on the analysis of observations of the Type II-L supernova LSQ13cuw within the framework of currently accepted physical predictions of core-collapse supernova explosions. LSQ13cuw was discovered within a day of explosion, ... More
Massive stars exploding in a He-rich circumstellar medium. VI. Observations of two distant Type Ibn supernova candidates discovered by La Silla-QUESTFeb 17 2015We present optical observations of the peculiar stripped-envelope supernovae (SNe) LSQ12btw and LSQ13ccw discovered by the La Silla-QUEST survey. LSQ12btw reaches an absolute peak magnitude of M(g) = -19.3 +- 0.2, and shows an asymmetric light curve. ... More
Measurement of the $^{1}H$($\vecγ$, $\vec{p}$)$π^{0}$ reaction using a novel nucleon spin polarimeterSep 30 2013We report the first large-acceptance measurement of polarization transfer from a polarized photon beam to a recoiling nucleon, pioneering a novel polarimetry technique with wide application to future nuclear and hadronic physics experiments. The commissioning ... More
Target and Double Spin Asymmetries of Deeply Virtual $π^0$ Production with a Longitudinally Polarized Proton Target and CLASNov 10 2015Dec 04 2015The target and double spin asymmetries of the exclusive pseudoscalar channel $\vec e\vec p\to ep\pi^0$ were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized ... More
Target and Double Spin Asymmetries of Deeply Virtual $π^0$ Production with a Longitudinally Polarized Proton Target and CLASNov 10 2015Mar 15 2017The target and double spin asymmetries of the exclusive pseudoscalar channel $\vec e\vec p\to ep\pi^0$ were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized ... More
PESSTO : survey description and products from the first data release by the Public ESO Spectroscopic Survey of Transient ObjectsNov 02 2014May 10 2015The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. We describe the data reduction strategy and data products which are publicly available through the ESO archive ... More
Target and Beam-Target Spin Asymmetries in Exclusive Pion Electroproduction for $Q^2>1$ GeV$^2$. I. $e p \rightarrow e π^+ n$Jul 26 2016Oct 10 2016Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $\pi^+$ electroproduction reaction $\gamma^* p \to n \pi^+$. The results were obtained from scattering of 6 GeV longitudinally polarized electrons off ... More
Alternative PV Bus Modelling with the Holomorphic Embedding Load Flow MethodJul 01 2016The Holomorphic Embedding Load Flow Method (HELM) has been suggested as an alternative approach to solve load flow problems. However, the current literature does not provide any HELM models that can accurately handle general power networks containing ... More
The Beam-Target Helicity Asymmetry for $\vecγ \vec{n} \rightarrow π^- p$ in the {\bf{$N^*$} Resonance RegionMay 12 2017We report the first beam-target double-polarization asymmetries in the $\gamma + n(p) \rightarrow \pi^- + p(p)$ reaction spanning the nucleon resonance region from invariant mass $W$= $1500$ to $2300$ MeV. Circularly polarized photons and longitudinally ... More
Binary black hole initial data for numerical general relativity based on post-Newtonian dataJul 02 2002With the goal of taking a step toward the construction of astrophysically realistic initial data for numerical simulations of black holes, we for the first time derive a family of fully general relativistic initial data based on post-2-Newtonian expansions ... More
Low-voltage organic transistors and inverters with ultra-thin fluoropolymer gate dielectricNov 06 2009We report on the simple fabrication of hysteresis-free and electrically stable organic field-effect transistors (OFETs) and inverters operating at voltages <1-2 V, enabled by the almost trap-free interface between the organic semiconductor and an ultra-thin ... More
The Effelsberg-Bonn HI Survey: Data reductionMay 25 2010Starting in winter 2008/2009 an L-band 7-Feed-Array receiver is used for a 21-cm line survey performed with the 100-m telescope, the Effelsberg-Bonn HI survey (EBHIS). The EBHIS will cover the whole northern hemisphere for decl.>-5 deg comprising both ... More
The Effelsberg Bonn HI Survey EBHISOct 08 2009The Effelsberg-Bonn HI Survey (EBHIS) covers the whole sky north of Dec(2000) = -5 deg. on a fully sampled angular grid. Using state-of-the-art FPGA-spectrometers we perform a Milky Way and an extragalactic HI survey in parallel. Moreover, the high dynamic ... More
Charged-particle detection efficiencies of close-packed CsI arraysDec 05 2016Detector efficiency determination is essential to correct the measured yields and extract reliable cross sections of particles emitted in nuclear reactions. We investigate the efficiencies for measuring the full energies of light charged particle in arrays ... More
Cosmological Galaxy Evolution with Superbubble Feedback II: The Limits of SupernovaeApr 27 2016Apr 29 2016We explore when supernovae can (and cannot) regulate the star formation and bulge growth in galaxies based on a sample of 18 simulated galaxies. The simulations include key physics such as evaporation and conduction, neglected in prior work, and required ... More
Dynamics of a period-three pattern loaded Bose-Einstein condensate in an optical latticeDec 16 2002We discuss the dynamics of a Bose-Einstein condensate initially loaded into every third site of an optical lattice using a description based upon the discrete nonlinear Schrodinger equation. An analytic solution is developed for the case of a periodic ... More