13โ€“18 Dec 2015
International Conference Centre Geneva
Europe/Zurich timezone

Session

18 - Gal. accel. & pulsars

Gal. Accel.
14 Dec 2015, 14:00
International Conference Centre Geneva

International Conference Centre Geneva

17 Rue de Varembรฉ, 1211 Geneva

Conveners

18 - Gal. accel. & pulsars: Galactic accelerators

  • Marco Tavani (INAF)

18 - Gal. accel. & pulsars: Galactic accelerators

  • Marco Tavani (INAF)

18 - Gal. accel. & pulsars: Pulsars

  • Marco Tavani (INAF)

18 - Gal. accel. & pulsars: Pulsars

  • Marco Tavani (INAF)

Presentation materials

There are no materials yet.

  1. Nukri Komin (Wits University)
    14/12/2015, 14:00
    Talk
    The Large Magellanic Cloud (LMC) is an irregular satellite galaxy of the Milky Way, which has been observed extensively at Very-High-Energy (VHE) gamma-rays with the H.E.S.S. telescopes, obtaining a deep exposure of 210 hours. In this talk we will present the results of this campaign. Besides the already known PWN N 157B, these observations establish significant VHE gamma-ray emission from...
    Go to contribution page
  2. Dr Thierry Stolarczyk (IRFU/SAp,CEA Saclay, 91190 Gif-sur-Yvette (FR))
    14/12/2015, 14:20
    Talk
    CTA is the next generation ground based gamma-ray observatory planned to start operations before the end of the decade. With tens of telescopes on sites in both hemispheres, it will allow probing the Milky Way with an unprecedented sensitivity and angular resolution, in the energy domain from a few tens of GeV to a few hundreds of TeV. I will review the CTA Galactic science program ranging...
    Go to contribution page
  3. Dr Shiu Hang (Herman) Lee (ISAS/JAXA)
    14/12/2015, 14:45
    Talk
    Recent observations by the Large Area Telescope (LAT) onboard the Fermi satellite have revealed bright gamma-ray emission from middle-aged supernova remnants (SNRs) inside our Galaxy. These remnants which also possess bright non-thermal radio shells are often found to be interacting directly with surrounding gas clouds. We explore the non-thermal emission mechanism at these dynamically evolved...
    Go to contribution page
  4. Maria Chernyakova (DCU)
    14/12/2015, 15:05
    Talk
    Gamma-ray loud binaries are are a recently identified class of X-ray binaries in which interaction of an outflow from the compact object (black hole or neutron star) with the wind and radiation emitted by a companion star leads to the production of very-high energy (VHE) gamma-ray emission. Only five systems have been firmly detected so far as persistent or regularly variable TeV gamma-ray...
    Go to contribution page
  5. Matteo Balbo (Universitรฉ de Genรจve)
    14/12/2015, 15:25
    Talk
    The Fermi Large Area Telescope (LAT) observed for the first time ever two consecutive $\eta$Carinae periastron passages. The large field of view of the instrument, its performing sensitivity and homogeneous exposition offers a continuous observation above 100 MeV of the $\eta$Carinae region on the last 7 years. $\eta$Carinae is a binary system hosted in the Carina nebula. Its luminous blue...
    Go to contribution page
  6. Dr Takayuki Saito (Kyoto University)
    14/12/2015, 16:15
    Talk
    Although more than 150 gamma-ray pulsars are known in GeV band, their spectra roll off above 10 GeV and only two pulsars are detected at about 50 GeV, namely Crab and Vela. There is also a large difference between Crab and Vela. Crab spectrum is extending above 1 TeV, while Vela has a very soft spectrum, becoming almost undetectable at 100 GeV. In order to further understand the emission...
    Go to contribution page
  7. Chandreyee Maitra (CEA Saclay)
    14/12/2015, 16:35
    Talk
    PSR J0855-4644 is a nearby, fast spinning, and energetic radio pulsar spatially coincident with the rim of the supernova remnant RX J0852.0-4622 (aka Vela Jr). XMM Newton observations of the pulsar region have shown an arcmin scale extended emission, the pulsar wind nebula (PWN), around the X-ray counterpart of the pulsar. Here, we present results from the small scale structure of the nebula...
    Go to contribution page
  8. Joseph D Gelfand
    14/12/2015, 16:55
    Talk
    TeV gamma-rays indicate the presence of extremely high-energy particles. While many discrete TeV sources have been identified in the Galactic plane, the origin of these particles is often unclear. This is especially true for HESS J1640-465, among the most luminous TeV sources in the Milky Way, which is coincident with both a radio supernova remnant and an energetic X-ray pulsar and pulsar...
    Go to contribution page
  9. Mr Simone Giacche` (Max-Planck Institute for Nuclear Physics)
    14/12/2015, 17:15
    Talk
    The Pulsar Wind Nebulae (PWNe) PSR B1259-63 has been observed to emit periodic GeV flares, whose power can be comparable to the total pulsar spin-down luminosity. Because of the short timescale involved, these photons are likely to be produced via inverse Compton scattering of stellar photons or Synchrotron radiation by a population of very energetic electrons (from GeV to TeV energies)...
    Go to contribution page
  10. John Kirk
    14/12/2015, 17:35
    Talk
    Perpendicular shocks are shown to be rapid astrophysical particle accelerators. They perform optimally when the ratio of the shock speed to the particle speed roughly equals the ratio of the scattering rate to the gyro frequency. Analytical methods and Monte-Carlo simulations are used to solve the kinetic equation that govern the anisotropy generated at these shocks,...
    Go to contribution page
  11. Dr Krzysztof Nalewajko (Stanford University)
    14/12/2015, 17:55
    Talk
    We will present the results of kinetic particle-in-cell numerical simulations of relativistic harmonic magnetic equilibria, so called "ABC fields". These equilibria have been recently shown by relativistic magnetofluid simulations to be generally unstable. An ideal plasma instability leads to the formation of dynamical current layers where magnetic energy is dissipated via reconnection and...
    Go to contribution page
  12. Jรฉrรดme Pรฉtri (Universitรฉ de Strasbourg)
    14/12/2015, 18:15
    Poster
    The magnetic field topology in the surrounding of neutron stars is one of the key questions in pulsar magnetospheric physics. A very extensive literature exists about the assumption of a dipolar magnetic field but very little progress has been made in attempts to include multipolar components in a self-consistent way. In this talk, we study the effect of multipolar electromagnetic fields...
    Go to contribution page
  13. Aurรฉlien Sourie (LUTH - Observatoire de Paris)
    15/12/2015, 14:00
    Talk
    We present a realistic numerical model for rotating superfluid neutron stars in a full general relativistic framework. Following the work initiated by Prix, Novak & Comer [1], we compute stationary axisymmetric configurations of neutron stars composed of two fluids, namely superfluid neutrons and charged particles (protons and electrons), which are free to rotate around a common axis with...
    Go to contribution page
  14. Brynmor Haskell (The University of Melbourne)
    15/12/2015, 14:21
    Talk
    Neutron stars are an exceptional fundamental physics laboratory, and provide us with the only opportunity to study the strong interaction at high densities and low temperatures. These objects are, in fact, not only very dense (with central densities surpassing nuclear saturation density), but also cold, as their thermal energy is generally negligible compared to the Fermi energy of the...
    Go to contribution page
  15. Benoit Cerutti (Princeton University)
    15/12/2015, 14:42
    Talk
    Pulsars shine throughout the electromagnetic spectrum, from radio waves to energetic gamma rays. The radio emission is thought to originate from the discharge of the polar-cap and the formation of copious electron-positron pairs. Gamma rays are traditionally associated with particle acceleration in electrostatic gaps within the light cylinder. The recent development of global Particle-In-Cell...
    Go to contribution page
  16. Dr Jaroslaw Dyks (Nicolaus Copernicus Astronomical Center)
    15/12/2015, 15:02
    Talk
    The knowledge of radio emission geometry is crucial for interpreting their gamma-ray profiles, and for establishing the orientation of their tilted magnetic field. I will review the continually increasing evidence against the most popular (nested cone) radio beam geometry. It will be shown that several features of pulse profiles, which have normally been considered as signatures of the...
    Go to contribution page
  17. Lucia Pavan (University of Geneva)
    15/12/2015, 15:22
    Talk
    Despite jets are detected in all kind of accreting systems, bright and elongated jets are known to be formed also by isolated rotationally powered pulsars. PSR J1101-6101 in the Lighthouse Nebula is an isolated pulsar which is powering a bright wind nebula and two jets, while travelling at supersonic velocity in the interstellar medium. Extending over 15 pc, the jets are more than 10 times...
    Go to contribution page
  18. Lab Saha (Nicolaus Copernicus Astronomical Center, Torun, Poland)
    15/12/2015, 15:42
    Poster
    Average profiles of some radio pulsars contain weak emission components which cover large intervals of pulse phase as well as localised emission or absorption features. The polarisation-angle (PA) under such features exhibits local distortions which cannot be explained through the rotating vector model and other effects such as the special relativistic effects or modification of...
    Go to contribution page
  19. Norbert Schartel (ESA)
    15/12/2015, 16:15
    Talk
    With about 300 refereed papers published each year, XMM-Newton is one of the most successful scientific missions of ESA ever. Neutron stars are classical targets of X-ray observatories and consequently huge expectations were accompanying the lunch of the spacecraft. Contrary to expectations, the spectra of neutron stars were generally found continuum dominated exclusive any spectral...
    Go to contribution page
  20. Jรฉrรดme Pรฉtri (Universitรฉ de Strasbourg)
    15/12/2015, 16:35
    Talk
    Pulsar magnetospheres are shaped by ultra-relativistic electron/positron plasmas flowing in a strong magnetic field and subject to strong gravitational fields. The former induces magnetospheric currents and space charges responsible for the distortion of the electromagnetic field based on pure electrodynamics. The latter induces other perturbations in these fields based on space-time...
    Go to contribution page
  21. Maxim Lyutikov
    15/12/2015, 16:55
    Talk
    Using the latest multi-wavelength observations of the inner-most regions of Crab nebular, we develop a model of relativistic pulsar winds that reproduces the detailed morphology of the Crab inner knot. We infer that a large equatorial sector of the wind, responsible for the production of the inner knot, is a low-magnetized flow - we see directly the surface of the termination shock. At...
    Go to contribution page
  22. Mikhail Belyaev (UC Berkeley/TAC)
    15/12/2015, 17:15
    Talk
    We perform 2.5D axisymmetric simulations of the pulsar magnetosphere (aligned dipole rotator) using the charge conservative, relativistic, electromagnetic particle in cell code PICsar. The particle in cell method is a powerful tool for studying the pulsar magnetosphere, because it can handle the force-free and vacuum limits as well as magnetic reconnection. In particular, dissipative regions...
    Go to contribution page
  23. Jรฉrรดme Pรฉtri (Universitรฉ de Strasbourg)
    15/12/2015, 17:35
    Talk
    Geodetic precession has been observed directly in the double-pulsar PSR J0737-3039. Its rate has even been measured and agrees with predictions of general relativity. Very recently, the double pulsar has been detected in X-rays and gamma-rays. This fuels the hope observing geodetic precession in its high-energy pulse profile. Unfortunately, the geometric configuration of the binary renders any...
    Go to contribution page
  24. Guillaume Belanger (ESA)
    15/12/2015, 17:55
    Poster
    We present here the results of an analysis of 15 years of regular XMM-Newton EPIC pn observations of the Crab pulsar. The analysis of its pulse profile is based on a multi-harmonic decomposition using a new periodogram statistic which is ideally suited for studying the details of the characteristics of peaked pulse profiles such as the Crabโ€™s, especially in time-tagged event data. The...
    Go to contribution page
Building timetable...