GALPROP WebRun: an internet-based service for calculating galactic cosmic ray propagation and associated photon emissions

GALPROP is a numerical code for calculating the galactic propagation of relativistic charged particles and the diffuse emissions produced during their propagation. The code incorporates as much realistic astrophysical input as possible together with latest theoretical developments and has become a de facto standard in astrophysics of cosmic rays. We present GALPROP WebRun, a service to the scientific community enabling easy use of the freely available GALPROP code via web browsers. In addition, we introduce the latest GALPROP version 54, available through this service.Comment: Accepted for publication in Computer Physics Communications. Version 2 includes improvements suggested by the referee. Metadata completed in version 3 (no changes to the manuscript

Stamp Ornamented Pottery From the Kniazha Hora Site (based on excavations 1958–1965)

The article is devoted to the publication of the pottery with a stamp design from the Kniazha Hora Old Rus fortress. During field seasons of 1958–1965, a representative collection of ceramic products was found on the settlement by a detachment of the Slavic-Rus archaeology of the Kaniv complex expedition under the direction of Halyna Mezentseva. Pots that are decorated with geometric figures-stamps are noteworthy because they are rare for the Kniazha Hora area. Studying ornamentation is very important because the décor reflects some aspects of the spiritual culture of ancient population. However, these unique findings have not been given due attention by previous researchers. In the papers, the stamp type of ornament is associated with the West Slavonic tradition. It testifies one more peculiarity of the Old Rus society’s culture, in particular, of the Kniazha Hora fortress

Constraints on cosmic-ray propagation models from a global Bayesian analysis

Research in many areas of modern physics such as, e.g., indirect searches for dark matter and particle acceleration in SNR shocks, rely heavily on studies of cosmic rays (CRs) and associated diffuse emissions (radio, microwave, X-rays, gamma rays). While very detailed numerical models of CR propagation exist, a quantitative statistical analysis of such models has been so far hampered by the large computational effort that those models require. Although statistical analyses have been carried out before using semi-analytical models (where the computation is much faster), the evaluation of the results obtained from such models is difficult, as they necessarily suffer from many simplifying assumptions, The main objective of this paper is to present a working method for a full Bayesian parameter estimation for a numerical CR propagation model. For this study, we use the GALPROP code, the most advanced of its kind, that uses astrophysical information, nuclear and particle data as input to self-consistently predict CRs, gamma rays, synchrotron and other observables. We demonstrate that a full Bayesian analysis is possible using nested sampling and Markov Chain Monte Carlo methods (implemented in the SuperBayeS code) despite the heavy computational demands of a numerical propagation code. The best-fit values of parameters found in this analysis are in agreement with previous, significantly simpler, studies also based on GALPROP.Comment: 19 figures, 3 tables, emulateapj.sty. A typo is fixed. To be published in the Astrophysical Journal v.728 (February 10, 2011 issue). Supplementary material can be found at http://www.g-vo.org/pub/GALPROP/GalpropBayesPaper

Microwave Response of V3Si Single Crystals: Evidence for Two-Gap Superconductivity

The investigation of the temperature dependences of microwave surface impedance and complex conductivity of V3Si single crystals with different stoichiometry allowed to observe a number of peculiarities which are in remarkable contradiction with single-gap Bardeen-Cooper-Schrieffer theory. At the same time, they can be well described by two-band model of superconductivity, thus strongly evidencing the existence of two distinct energy gaps with zero-temperature values Delta1~1.8Tc and Delta2~0.95Tc in V3Si.Comment: Submitted to Europhysics Letter

GALPROP: modeling cosmic ray propagation and associated interstellar emissions

Research in many areas of modern physics and astrophysics such as, e.g., indirect searches for dark matter (DM), particle acceleration in SNR shocks, and the spectrum and origin of extragalactic gamma-ray background, rely heavily on studies of cosmic rays (CRs) and associated diffuse emissions. New or improved instrumentation to explore these open issues is ready or under development. A fleet of ground-based, balloon-borne, and spacecraft instruments measures many CR species, gamma rays, radio, and synchrotron emission. Exploiting the data collected by the scientific missions to the fullest requires reliable and detailed calculations using a numerical model. GALPROP is the current state-of-the-art numerical CR propagation code that has become a standard analysis tool in CR and diffuse gamma-ray research. It uses astrophysical information, nuclear and particle data as input to self-consistently predict CRs, gamma rays, synchrotron emission and other observables. This paper reviews recent GALPROP developments and results.Comment: Invited talk at 8th Workshop on Science with the New Generation of High Energy Gamma-ray Experiments: Gamma-ray Astrophysics in the Multimessenger Context (SciNeGHE2010, Trieste, Sept. 8-10, 2010); Il Nuovo Cimento C, v. 034, published onlin

Three-band superconductivity and the order parameter that breaks time-reversal symmetry

We consider a model of multiband superconductivity, inspired by iron pnictides, in which three bands are connected via repulsive pair-scattering terms. Generically, three distinct superconducting states arise within such a model. Two of them are straightforward generalizations of the two-gap order parameter while the third one corresponds to a time-reversal symmetry breaking order parameter, altogether absent within the two-band model. Potential observation of such a genuinely frustrated state would be a particularly vivid manifestation of the repulsive interactions being at the root of iron-based high temperature superconductivity. We construct the phase diagram of this model and discuss its relevance to the iron pnictides family of high temperature superconductors. We also study the case of the Josephson coupling between a two-band s' (or extended s-wave) superconductor and a single-gap s-wave superconductor, and the associated phase diagram.Comment: 9 pages, 9 figures. Added discussion and references, one new figure (Fig. 3