Analysis of the Swift Gamma-Ray Bursts duration

Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third type of burst. Swift satellite detectors have different spectral sensitivity than pre-Swift ones for gamma-ray bursts. Therefore it is worth to reanalyze the durations and their distribution and also the classification of GRBs. Using The First BAT Catalog the maximum likelihood estimation was used to analyzed the duration distribution of GRBs. The three log-normal fit is significantly (99.54 % probability) better than the two for the duration distribution. Monte-Carlo simulations also confirm this probability (99.2 %).Comment: NANJING GAMMA-RAY BURST CONFERENCE 200

Quantitative sensory testing of the equine face

Background: Quantitative sensory testing methods are now standard in the evaluation of sensory function in man, while few normal equine values have been reported. Objectives: The aim of this experimental study was (a) to define the tactile sensory, mechanical nociceptive and thermal nociceptive thresholds of the equine face; (b) to assess the effect of age, sex, stimulation site and shaving; (c) to evaluate the reliability of the methods and (d) to provide reference facial quantitative sensory testing values. Study design: Method description. Methods: Thirty-four healthy Warmblood horses were used in the study. Six (tactile sensory threshold) and five (mechanical nociceptive and thermal nociceptive thresholds) areas of the left side of the face with clear anatomical landmarks were evaluated. Ten horses had two (mechanical nociceptive threshold) or three (tactile sensory and thermal nociceptive thresholds) of these areas shaved for another study. A linear Mixed model was used for data analysis. Results: All thresholds increased with age (tactile sensory threshold: by 0.90 g/y (CI = [0.12 g; 0.36 g]) P = .001; mechanical nociceptive threshold: by 0.25 N/y (CI = [0.13-0.36 N]) P = .000; thermal nociceptive threshold: by 0.2°C/y (CI = [0.055-0.361]) P = .008). Sex had no effect on thresholds (tactile sensory threshold: P = .1; mechanical nociceptive threshold: P = .09; thermal nociceptive threshold: P = .2). Stimulation site affected tactile sensory and mechanical nociceptive thresholds (P = .001 and P = .008), but not thermal nociceptive threshold (P = .9). Shaving had no significant effect on any of the thresholds (tactile sensory threshold: P = .06; mechanical nociceptive threshold: P = .08; thermal nociceptive threshold: P = .09). Main limitations: Only the left side was investigated and measurements were obtained on a single occasion. Conclusions: Handheld quantitative sensory testing does not require shaving or clipping to provide reliable measurements. Stimulation over the nostril (tactile sensory threshold), temporomandibular joint (mechanical nociceptive threshold) and supraorbital foramen (thermal nociceptive threshold) resulted in the most consistent thresholds

The obscured hyper-energetic GRB 120624B hosted by a luminous compact galaxy at z = 2.20

Gamma-ray bursts are the most luminous explosions that we can witness in the Universe. Studying the most extreme cases of these phenomena allows us to constrain the limits for the progenitor models. In this Letter, we study the prompt emission, afterglow, and host galaxy of GRB 120624B, one of the brightest GRBs detected by Fermi, to derive the energetics of the event and characterise the host galaxy in which it was produced. Following the high-energy detection we conducted a multi-wavelength follow-up campaign, including near-infrared imaging from HAWKI/VLT, optical from OSIRIS/GTC, X-ray observations from the Chandra X-ray Observatory and at sub-millimetre/millimetre wavelengths from SMA. Optical/nIR spectroscopy was performed with X-shooter/VLT. We detect the X-ray and nIR afterglow of the burst and determine a redshift of z = 2.1974 +/- 0.0002 through the identification of emission lines of [OII], [OIII] and H-alpha from the host galaxy of the GRB. This implies an energy release of Eiso = (3.0+/-0.2)x10^54 erg, amongst the most luminous ever detected. The observations of the afterglow indicate high obscuration with AV > 1.5. The host galaxy is compact, with R1/2 < 1.6 kpc, but luminous, at L ~ 1.5 L* and has a star formation rate of 91 +/- 6 Msol/yr as derived from H-alpha. As other highly obscured GRBs, GRB 120624B is hosted by a luminous galaxy, which we also proof to be compact, with a very intense star formation. It is one of the most luminous host galaxies associated with a GRB, showing that the host galaxies of long GRBs are not always blue dwarf galaxies, as previously thought.Comment: 6 pages, 4 figures, 4 tables; accepted for publication in A&

Radiation distributions in TCV

Total radiative powers measured by foil bolometer and AXUV camera systems are compared to SOLPS5 simulations in low and high density deuterium and helium diverted discharges on the TCV tokamak. For low density the match between simulation and measurements is satisfactory, but at high density strongly radiating regions outside the SOLPS5 simulation grid are seen in measurements and this may indicate the presence of enhanced convective particle transport in the low field side midplane region. The chord coverage of the foil bolometer system does not, however, allow detailed resolution in this region. The comparison of foil and AXUV data also demonstrates that ageing of the AXUV diodes under plasma irradiation combined with the unevenness of the diode spectral response, strongly limits their application for total radiative power measurements. (c) 2007 Elsevier B.V. All rights reserved

Cosmology and the Subgroups of Gamma-ray Bursts

Both short and intermediate gamma-ray bursts are distributed anisotropically in the sky (Mészáros, A. et al. ApJ, 539, 98 (2000), Vavrek, R. et al. MNRAS, 391, 1 741 (2008)). Hence, in the redshift range, where these bursts take place, the cosmological principle is in doubt. It has already been noted that short bursts should be mainly at redshifts smaller than one (Mészáros, A. et al. Gamma-ray burst: Sixth Huntsville Symp., AIP, Vol. 1 133, 483 (2009); Mészáros, A. et al. Baltic Astron., 18, 293 (2009)). Here we show that intermediate bursts should be at redshifts up to three

Point source in a phononic grating: stop bands give rise to phonon-focusing caustics

We use locally-excited gigahertz surface phonon wavepackets in microscopic line structures of different pitches to reveal profound anisotropy in the radiation pattern of a point source in a grating. Time-domain data obtained by an ultrafast optical imaging technique and by numerical simulations are Fourier transformed to obtain frequency-filtered real-space acoustic field patterns and k-space phononic band structure. The numerically-obtained k-space images are processed to reveal an intriguing double-horn structure in the lowest-order group-velocity surface, which explains the observed non-propagation sectors bounded by caustics, noted at frequencies above the bottom of the first stop band. We account for these phonon-focusing effects, analogous to collimation effects previously observed in two- and three-dimensional lattices, with a simple analytical model of the band structure based on a plane wave expansion. As the frequency is increased, a transition to dominant waveguiding effects along the lines is also documented

Reconfigurable Autonomy

This position paper describes ongoing work at the Universities of Liverpool, Sheffield and Surrey in the UK on developing hybrid agent architectures for controlling autonomous systems, and specifically for ensuring that agent-controlled dynamic reconfiguration is viable. The work outlined here forms part of the Reconfigurable Autonomy research project

Searching for differences in Swift's intermediate GRBs

Gamma-ray bursts are usually classified through their high-energy emission into short-duration and long-duration bursts, which presumably reflect two different types of progenitors. However, it has been shown on statistical grounds that a third, intermediate population is needed in this classification scheme, although an extensive study of the properties of this class has so far not been done. The large amount of follow-up studies generated during the Swift era allows us to have a suficient sample to attempt a study of this third population through the properties of their prompt emission and their afterglows. Our study is focused on a sample of GRBs observed by Swift during its first four years of operation. The sample contains those bursts with measured redshift since this allows us to derive intrinsic properties. Intermediate bursts are less energetic and have dimmer afterglows than long GRBs, especially when considering the X-ray light curves, which are on average one order of magnitude fainter than long bursts. There is a less significant trend in the redshift distribution that places intermediate bursts closer than long bursts. Except for this, intermediate bursts show similar properties to long bursts. In particular, they follow the Epeak vs. Eiso correlation and have, on average, positive spectral lags with a distribution similar to that of long bursts. Like long GRBs, they normally have an associated supernova, although some intermediate bursts have shown no supernova component. This study shows that intermediate bursts are different from short bursts and, in spite of sharing many properties with long bursts, there are some differences between them as well. We suggest that the physical difference between intermediate and long bursts could be that for the first the ejecta are thin shells while for the latter they are thick shells.Comment: Accepted for publication in Astronomy and Astrophysics. 16 pages, 17 figures, 5 table