All posts by John Wise

Assistant Professor in Physics at Georgia Tech

05 Oct 2011

  • (abs, pdf) Rocha et al., Infall Times for Milky Way Satellites From Their Present-Day Kinematics
  • (abs, pdf) Trenti et al., Overdensities of Y-dropout Galaxies from the Brightest-of-Reionizing Galaxies Survey: A Candidate Protocluster at Redshift z~8
  • (abs, pdf) Petkova & Maio, Radiative feedback on early molecular gas and implications for primordial structure formation
  • (abs, pdf) Maio & Khochfar, The imprint of cosmological non-Gaussianities on primordial structure formation
  • (abs, pdf) Bolton et al., Improved measurements of the intergalactic medium temperature around quasars: possible evidence for the initial stages of He-II reionisation at z~6
  • (abs, pdf) Pan et al., The Pollution of Pristine Material in Compressible Turbulence
  • (abs, pdf) Mignone et al., Adaptive Mesh Refinement with the PLUTO Code for Astrophysical Fluid Dynamics

GPU Meeting (04 Oct 2011)

Lionel London (CRA) – GPU Computing in Matlab

  • Matlab Parallel Computing Toolbox (PCT) vs. Jacket
  • PCT allows for multi-cpu and GPU computing. Limited to 12 cores on the local machine. Very high level.
  • GPU computing with PCT requires an nVidia card with v1.3 compute capabilities. GPGPU with Jacket has relaxed requirements but is very expensive ($4k for 5 licenses!)
  • PCT GPU can run external .cu files.
  • Jacket has 10x more CUDA-enabled functions than Matlab.  It’s cluster capable.

Talk: Magnetar Dynamics & Grav. Waves

Kostas Kokkotas (Tübingen)

  • Magnetars exhibit regular gamma-ray flares that are preceded by star quakes or glitches in the pulsations.  The largest flares have L ~ 10^47 erg/s (3 since 1979).
  • No natural explanation for (1) sudden stop of activity P ~ 12 sec and (2) AXP-SNR association but no SGR-SNR association
  • Thompson & Duncan (1990’s) – developed a fireball model that erupts from the NS surface to explain these largest bursts.
  • Can QPOs be explained by global Alfvèn waves?  (see KK publications)
  • NS models, using perturbation theory, with crust and B-fields to predict QPO frequencies.  No crust oscillations at B > 4 x 10^14 G.
  • Gravitational wave amplitudes are unknown and must be calculated with simulations (3D GRMHD).
  • Simulation of B-field instability (Lasky et al. 2011, ApJL) and prediction for GW (Zink et al. 2011)