bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards multi-threaded local tabling using a common table space
Authors: AREIAS MIGUEL , ROCHA RICARDO 
Published: September 2012

AbstractMulti-threading is currently supported by several well-known Prolog systems providing a highly portable solution for applications that can benefit from concurrency. When multi-threading is combined with tabling, we can exploit the power of higher procedural control and declarative semantics. However, despite the availability of both threads and tabling in some Prolog systems, the implementation of these two features implies complex ties to each other and to the underlying engine. Until now, XSB was the only Prolog system combining multi-threading with tabling. In XSB, tables may be either private or shared between threads. While thread-private tables are easier to implement, shared tables have all the associated issues of locking, synchronization and potential deadlocks. In this paper, we propose an alternative view to XSB's approach. In our proposal, each thread views its tables as private but, at the engine level, we use a common table space where tables are shared among all threads. We present three designs for our common table space approach: No-Sharing (NS) (similar to XSB's private tables), Subgoal-Sharing (SS) and Full-Sharing (FS). The primary goal of this work was to reduce the memory usage for the table space but, our experimental results, using the YapTab tabling system with a local evaluation strategy, show that we can also achieve significant reductions on running time.
Annotation of logic programs for independent AND-parallelism by partial evaluation
Authors: VIDAL GERMAN 
Published: September 2012

AbstractTraditional approaches to automatic AND-parallelization of logic programs rely on some static analysis to identify independent goals that can be safely and efficiently run in parallel in any possible execution. In this paper, we present a novel technique for generating annotations for independent AND-parallelism that is based on partial evaluation. Basically, we augment a simple partial evaluation procedure with (run-time) groundness and variable sharing information so that parallel conjunctions are added to the residual clauses when the conditions for independence are met. In contrast to previous approaches, our partial evaluator is able to transform the source program in order to expose more opportunities for parallelism. To the best of our knowledge, we present the first approach to a parallelizing partial evaluator.
Relative expressiveness of defeasible logics
Authors: MAHER MICHAEL J. 
Published: September 2012

AbstractWe address the relative expressiveness of defeasible logics in the frameworkDL. Relative expressiveness is formulated as the ability to simulate the reasoning of one logic within another logic. We show that such simulations must be modular, in the sense that they also work if applied only to part of a theory, in order to achieve a useful notion of relative expressiveness. We present simulations showing that logics inDLwith and without the capability of team defeat are equally expressive. We also show that logics that handle ambiguity differently – ambiguity blocking versus ambiguity propagating – have distinct expressiveness, with neither able to simulate the other under a different formulation of expressiveness.
Amicus Curiae Pro Bono Publico: Open Access Online Publication at the Institute of Advanced Legal Studies
Authors: Whittle Steven 
Published: September 2012

AbstractIn this paper Steven Whittle describes recent work at the Institute of Advanced Legal Studies to provide open online access to the IALS/SALS official journal Amicus Curiae and selected papers from the Institute's annual W. G. Hart Legal Workshop. It discusses some of the issues involved in a transition from print to web publication and looks at the benefits anticipated from additional web delivery.
Multiwavelength observations of GRB afterglows
Authors: Castro-Tirado Alberto J. 
Published: September 2012

AbstractMultiwavelength observations of gamma-ray burst afterglows are presented, in particular those in the optical and millimetre wavelengths. I will focus on the observations mostly carried out at Spanish ground-based observatories (mainly the 10.4m GTC) and at the Plateau de Bure Interferometer in the French Alps. The importance of global networks of robotic telescopes (like BOOTES, established worldwide) for early time observations in order to put constraints on the physical mechanisms of the GRB early time emission phase is also discussed. The overall observational efforts provide additional clues for a better understanding of the reverse and forward shock. Finally I will report on the Lomonosov/UFFO-p capabilities taking into account its launch in 2012.
Supernovae and Gamma-ray Bursts
Authors: Mazzali Paolo A. 
Published: September 2012

AbstractThe properties of the Supernovae discovered in coincidence with long-duration Gamma-ray Bursts and X-Ray Flashes are reviewed, and compared to those of SNe for which GRBs are not observed. The SNe associated with GRBs are of Type Ic, they are brighter than the norm, and show very broad absorption lines in their spectra, indicative of high expansion velocities and hence of large explosion kinetic energies. This points to a massive star origin, and to the birth of a black hole at the time of core collapse. There is strong evidence for gross asymmetries in the SN ejecta. The observational evidence seems to suggest that GRB/SNe are more massive and energetic than XRF/SNe, and come from more massive stars. While for GRB/SNe the collapsar model is favoured, XRF/SNe may host magnetars.
A shallow water analogue of asymmetric core-collapse, and neutron star kick/spin
Authors: Foglizzo Thierry , Masset Frédéric , Guilet Jérôme , Durand Gilles 
Published: September 2012

AbstractMassive stars end their life with the gravitational collapse of their core and the formation of a neutron star. Their explosion as a supernova depends on the revival of a spherical accretion shock, located in the inner 200km and stalled during a few hundred milliseconds. Numerical simulations suggest that the large scale asymmetry of the neutrino-driven explosion is induced by a hydrodynamical instability named SASI. Its non radial character is able to influence the kick and the spin of the resulting neutron star. The SWASI experiment is a simple shallow water analog of SASI, where the role of acoustic waves and shocks is played by surface waves and hydraulic jumps. Distances in the experiment are scaled down by a factor one million, and time is slower by a factor one hundred. This experiment is designed to illustrate the asymmetric nature of core-collapse supernova.
SN 2010jp (PTF10aaxi): A Jet-driven Type II Supernova
Authors: Smith Nathan , Cenko S. Bradley , Butler Nat , Bloom Joshua S. , Kasliwal Mansi M. , Horesh Assaf , Kulkarni Shrinivas R. , Law Nicholas M. , Nugent Peter E. , Ofek Eran O. , Poznanski Dovi , Quimby Robert M. , Sesar Branimir , Ben-Ami Sagi , Arcavi Iair , Gal-Yam Avishay , Polishook David , Xu Dong , Yaron Ofer , Frail Dale A. , Sullivan Mark 
Published: September 2012

AbstractWe present photometry and spectroscopy of the peculiar Type II supernova SN 2010jp, also named PTF10aaxi. The light curve exhibits a linear decline with a relatively low peak absolute magnitude of only −15.9 (unfiltered), and a low radioactive decay luminosity at late times that suggests a low synthesized nickel mass of about 0.003 M⊙ or less. Spectra of SN 2010jp display an unprecedented triple-peaked Hα line profile, showing: (1) a narrow central component that suggests shock interaction with a dense circumstellar medium (CSM); (2) high-velocity blue and red emission features centered at −12,600 and +15,400 km s−1; and (3) very broad wings extending from −22,000 to +25,000 km s−1. We propose that this line profile indicates a bipolar jet-driven explosion, with the central component produced by normal SN ejecta and CSM interaction at mid and low latitudes, while the high-velocity bumps and broad line wings arise in a nonrelativistic bipolar jet. Jet-driven SNe II are predicted for collapsars resulting from a wide range of initial masses above 25 M⊙, especially at the sub-solar metallicity consistent with the SN host environment. It also seems consistent with the apparently low 56Ni mass that may accompany black hole formation. We speculate that the jet survives to produce observable signatures because the star's H envelope was very low mass, having been mostly stripped away by the previous eruptive mass loss.
Luminosities, Masses and Star Formation Rates of Galaxies at High Redshift
Authors: Bunker Andrew J. 
Published: September 2012

AbstractThere has been great progress in recent years in discovering star forming galaxies at high redshifts (z > 5), close to the epoch of reionization of the intergalactic medium (IGM). The WFC3 and ACS cameras on the Hubble Space Telescope have enabled Lyman break galaxies to be robustly identified, but the UV luminosity function and star formation rate density of this population at z = 6 − 8 seems to be much lower than at z = 2 − 4. High escape fractions and a large contribution from faint galaxies below our current detection limits would be required for star-forming galaxies to reionize the Universe. We have also found that these galaxies have blue rest-frame UV colours, which might indicate lower dust extinction at z > 5. There has been some spectroscopic confirmation of these Lyman break galaxies through Lyman-α emission, but the fraction of galaxies where we see this line drops at z > 7, perhaps due to the onset of the Gunn-Peterson effect (where the IGM is opaque to Lyman-α).
Nucleosynthesis in neutrino-driven, aspherical Population III supernovae
Authors: Fujimoto Shin-ichiro , Hashimoto Masa-aki , Ono Masaomi , Kotake Kei 
Published: September 2012

AbstractWe investigate explosive nucleosynthesis during neutrino-driven, aspherical supernova (SN) explosion aided by standing accretion shock instability (SASI), based on two-dimensional hydrodynamic simulations of the explosion of 11, 15, 20, 25, 30 and 40M⊙ stars with zero metallicity. The magnitude and asymmetry of the explosion energy are estimated with simulations, for a given set of neutrino luminosities and temperatures, not as in the previous study in which the explosion is manually and spherically initiated by means of a thermal bomb or a piston and also some artificial mixing procedures are applied for the estimate of abundances of the SN ejecta.By post-processing calculations with a large nuclear reaction network, we have evaluated abundances and masses of ejecta from the aspherical SNe. We find that matter mixing induced via SASI is important for the abundant production of nuclei with atomic number ≥ 21, in particular Sc, which is underproduced in the spherical models without artificial mixing. We also find that the IMF-averaged abundances are similar to those observed in extremely metal poor stars. However, observed [K/Fe] cannot be reproduced with our aspherical SN models.
Gamma-Ray Bursts as Cosmological Probes
Authors: Totani Tomonori 
Published: September 2012

AbstractThe status and prospects for gamma-ray bursts (GRBs) as cosmological probes are reviewed. Long duration GRBs can potentially be used as an indicator of star formation rate (SFR), though GRB rate might be systematically different from SFR, by the effect of e.g. metallicity. There are several papers claiming that the cosmic GRB rate history is different from that of SFR in the sense that GRB rate is relatively higher than SFR at higher redshifts, which may be explained by the metallicity effect. However, considering the large uncertainties about the efficiency of GRB afterglow detection and redshift determination, it would be conservative to state that the observed GRB rate is roughly consistent with the star formation history. GRBs can also be used as a unique and powerful tool to reveal the reionization history. However, there is practically no progress in this direction since the first GRB-based useful constraint on reionization in 2005 (GRB 050904). The bottleneck now is the insufficient sensitivity of near-infrared spectroscopy, even with 8m class telescopes. The planned 30m class telescopes will bring the next breakthruough. Finally, GRBs can potentially be used as a standard candle to study cosmology by a geometrical test. However, there are still many steps for GRBs to overcome before it produces a result that has strong impact on the cosmology community in the precision cosmology era.
Spectropolarimetry of Type IIn SN2010jl: Peering Into the Heart of a Monster
Authors: Bauer Franz E. , Zelaya Paula , Clocchiatti Alejandro , Maund Justyn 
Published: September 2012

AbstractWe report results for two epochs of spectropolarimetry on the luminous type IIn SN2010jl, taken at ≈36 and 85 days post-explosion with VLT FORS2-PMOS. The high signal-to-noise data demonstrate distinct evolution in the continuum and the broad lines point to a complex origin for the various emission components and to a potentially common polarization signal for the type IIn class even over 1-2 orders of magnitude in luminosity output.
Supernova Nucleosynthesis with Neutrino Processes: Dependence of Fluorine abundance on Stellar Mass, Explosion Energy and Metallicity
Authors: Izutani Natsuko , Umeda Hideyuki , Yoshida Takashi 
Published: September 2012

AbstractWe investigate the effects of neutrino-nucleus interactions on the production of Fluorine during normal supernovae and hypernovae, and discuss stellar mass, metallicity and explosion energy dependence of [F/Fe,Ne,O]. We find the clear trend of [F/Fe,O,Ne] with stellar mass and explosion energy, while no clear trend with metallicity. This trend of [F/O] can be used to constrain the contributed stellar mass by comparing with the observational abundance.
Observing GRBs and Supernovae at Gemini Observatory as Target of Opportunity (ToO)
Authors: Lemoine-Busserolle M. , Roth K. C. , Carrasco E. R. , Miller B. W. , Stephens A. W. , Jorgensen I. , Rodgers B. 
Published: September 2012

AbstractThe Gemini Observatories primarily operate a multi-instrument queue, with observers selecting observations that are best suited to weather and seeing conditions. The Target of Opportunity (ToO) observing mode is intended to allow observation of targets that cannot be specified in advance but which have a well defined external trigger such as distant supernovae or Gamma Ray bursts. In addition, the instrument and configuration best suited to observe the ToO may depend on properties of the event, such as brightness and redshift which again are impossible to know in advance. Queue observing naturally lends itself to Target of Opportunity (ToO) support since the time required to switch between programs and instruments is very short, and the staff observer is trained to operate all the available instruments and modes. Gemini Observatory has supported pre-approved ToO programs since beginning queue operations, and has implemented a rapid (less than 15 minutes response time) ToO mode since 2005. ToOs comprise a significant fraction of the queue (20–25% of the highest ranking band) nowadays. We discuss the ToO procedures, the statistics of rapid ToOs observing at Gemini North Observatory, the science related to GRBs and supernovae that this important mode has enabled.
The Accretion-Powered Jet Propagations and Breakout Criteria for GRB Progenitors
Authors: Nagakura Hiroki , Suwa Yudai , Ioka Kunihito 
Published: September 2012

AbstractWe investigate the propagation of accretion-powered jets in various types of progenitor candidates of GRBs. We perform two dimensional axisymmetric simulations of relativistic hydrodynamics taking into account both the envelope collapse and the jet propagation. In our simulations, the accretion rate is estimated by the mass flux going through the inner boundary, and the jet is injected with a constant accretion-to-jet conversion efficiency η. By varying the efficiency η and opening angle θop for more than 30 models, we find that the jet can make a relativistic breakout from all types of progenitors for GRBs if a simple condition η ≳ 10−3 (θop/20°)2 is satisfied, that is consistent with analytical estimates, otherwise no explosion or some failed spherical explosions occur.
Radiation from accelerated particles in shocks
Authors: Nishikawa K.-I. , Zhang B. , Choi E. J. , Min K. W. , Niemiec J. , Medvedev M. , Hardee P. , Mizuno Y. , Nordlund A. , Frederiksen J. , Sol H. , Pohl M. , Hartmann D. H. , Fishman G.J. 
Published: September 2012

AbstractRecent PIC simulations of relativistic electron-positron (electron-ion) jets injected into a stationary medium show that particle acceleration occurs in the shocked regions. Simulations show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields and for particle acceleration. These magnetic fields contribute to the electron's transverse deflection behind the shock. The “jitter” radiation from deflected electrons in turbulent magnetic fields has properties different from synchrotron radiation calculated in a uniform magnetic field. This jitter radiation may be important for understanding the complex time evolution and/or spectral structure of gamma-ray bursts, relativistic jets in general, and supernova remnants. In order to calculate radiation from first principles and go beyond the standard synchrotron model, we have used PIC simulations. We present synthetic spectra to compare with the spectra obtained from Fermi observations.
Cosmological effects on the observed flux and fluence distributions of gamma-ray bursts
Authors: Řípa Jakub , Mészáros Attila , Ryde Felix 
Published: September 2012

AbstractSeveral claims have been put forward that an essential fraction of long-duration BATSE gamma-ray bursts should lie at redshifts larger than 5. This point-of-view follows from the natural assumption that fainter objects should, on average, lie at larger redshifts. However, redshifts larger than 5 are rare for bursts observed by Swift. The purpose of this article is to show that the most distant bursts in general need not be the faintest ones. We derive the cosmological relationships between the observed and emitted quantities, and arrive at a prediction that is tested on the ensembles of BATSE, Swift and Fermi bursts. This analysis is independent on the assumed cosmology, on the observational biases, as well as on any gamma-ray burst model. We arrive to the conclusion that apparently fainter bursts need not, in general, lie at large redshifts. Such a behaviour is possible, when the luminosities (or emitted energies) in a sample of bursts increase more than the dimming of the observed values with redshift. In such a case dP(z)/dz > 0 can hold, where P(z) is either the peak-flux or the fluence. This also means that the hundreds of faint, long-duration BATSE bursts need not lie at high redshifts, and that the observed redshift distribution of long Swift bursts might actually represent the actual distribution.
Origin of Ultra-High Energy Cosmic Rays: Nuclear Composition of Gamma-Ray Burst Jets
Authors: Shibata Sanshiro , Tominaga Nozomu 
Published: September 2012

AbstractUltra-high energy cosmic rays (UHECRs) are the most energetic particles flying from space and their source is not clarified yet. Recently, the Pierre Auger Observatory (PAO) suggests that UHECRs involve heavy nuclei. The PAO results require that a considerable fraction of metal nuclei must exist in the accelerating site, which can be realized only in the stellar interior. This puts strong constraints on the origin of UHECRs. In order to definitize the constraints from PAO results, we investigate the fraction of metal nuclei in a relativistic jet in gamma-ray burst associated with core-collapse supernova. If the jet is initially dominated by radiation field, quasi-statistical equilibrium (QSE) is established and heavy nuclei are dissociated to light particles such as 4He during the acceleration and expansion. On the other hand, if the jet is mainly accelerated by magnetic field heavy or intermediate mass nuclei can survive. The criterion to contain the metal nuclei is that the temperature at the launch site is below 4.5 × 109K. Therefore, if the composition of UHECRs is dominated by metal nuclei, a GRB with the magnetized jet is the most plausible candidate of the accelerating site.
Radio Insight into the Nature of Type IIb Progenitors
Authors: Stockdale Christopher J. , Ryder S. D. , Horesh A. , Weiler K. W. , Panagia N. , Van Dyk S. D. , Bauer F. E. , Immler S. , Sramek R. A. , Pooley D. , Marcaide J. M. , Kassim N. 
Published: September 2012

AbstractWe present the results of over two decades of radio observations of type IIb Supernovae with the Very Large Array and the Australia Telescope Compact Array. These radio studies illustrate the need for multi-wavelength follow-up to determine the progenitor scenario for type IIb events.
On the importance of the equation of state for the neutrino-driven supernova explosion mechanism
Authors: Suwa Yudai 
Published: September 2012

AbstractWe present two-dimensional numerical simulations of core-collapse supernova including multi-energy neutrino radiative transfer. We aim to examine the influence of the equation of state (EOS) for the dense nuclear matter. We employ four sets of EOSs, namely, those by Lattimer and Swesty (LS) and Shen et al., which became standard EOSs in the core-collapse supernova community. We reconfirm that not every EOS produces an explosion in spherical symmetry, which is consistent with previous works. In two-dimensional simulations, we find that the structure of the accretion flow is significantly different between LS EOS and Shen EOS, inducing an even qualitatively different evolution of the shock wave, namely, the LS EOS leads to shock propagation beyond 2000 km from the center, while the Shen EOS shows only oscillations within 500 km. The possible origins of the difference are discussed.
Optical to X-rays SNe light curves following shock breakout through a thick wind
Authors: Svirski Gilad , Nakar Ehud , Sari Re'em 
Published: September 2012

AbstractWe present luminosity and temperature light curves following supernova shock breakouts through a thick wind. These events are very luminous and their spectrum may contain both an X-ray and a UV/optical component. For breakout pulse durations between a week and a month, the X-ray component luminosity peaks 100-500 days after the explosion, respectively.
Type II-P supernovae in the mid-infrared
Authors: Szalai Tamás , Vinkó József 
Published: September 2012

AbstractWe present detailed analysis of mid-infrared (MIR) data for 9 type II-P supernovae from the public Spitzer database. Spectral energy distributions (SEDs) from observed fluxes are fitted with simple models to get basic information about the dust as the presumed source of MIR radiation. We found two SNe, 2005ad and 2005af, which likely have newly-formed dust in their environment, while in the other seven cases the observed MIR flux may originate from pre-existing circumstellar or interstellar dust.