Equisingularity classes of birational projections of normal singularities to a plane

Given a birational normal extension S of a two-dimensional local regular ring R, we describe all the equisingularity types of the complete ideals J in R whose blowing-up has some point at which the local ring is analytically isomorphic to S. The problem of classifying the germs of such normal surface singularities was already posed by Spivakovsky (Ann. of Math. 1990). This problem has two parts: discrete and continous. The continous part is to some extent equivalent to the problem of the moduli of plane curve singularities, while the main result of this paper solves completely the discrete part.Comment: 22 pages, 3 figures. To appear in Advances in Mathematic

Solar, Stellar and Galactic Connections between Particle Physics and Astrophysics

This book collects extended and specialized reviews on topics linking astrophysics and particle physics at a level intermediate between a graduate student and a young researcher. The book includes also three reviews on observational techniques used in forefront astrophysics and short articles on research performed in Latin America. The reviews, updated and written by specialized researchers, describe the state of the art in the related research topics. This book is a valuable complement not only for research but also for lecturers in specialized course of high energy astrophysics, cosmic ray astrophysics and particle physics

Very high energy gamma ray astronomy and non pulsating low mass x-ray binaries

This thesis is concerned with non pulsating Low Mass X-Ray Binaries as Very High Energy γ-ray sources, in particular Scorpius X-1; the brightest of these objects in X-rays, and the most likely to be detectable at energies above 250 GeV. After a first introductory chapter, experimental techniques presently used in Very High Energy γ-ray Astronomy are reviewed. In the third chapter statistical techniques used to quantify count rate excesses and orbital modulations are described and applied to data from Scorpius X-1. Data taken in 1988 and 1989 showing a 3cr count excess, reported previously elsewhere, are found to show orbital modulation at the 3% statistical level. The analysis of data taken on 1990 shows no signal. Periodicity tests, in particular the Rayleigh test, are also described. The principles of a segmented fast algorithm for period searches in Cerenkov data using memory limited, but relatively fast, micro-computers are shown in the fourth chapter. Various of these machines can be used simultaneously in order to achieve a large efficiency. A method to perform various trials per independent frequency is also presented. The results of period searches in data from three selected objects (Scorpius X-1, GX 5-1 and Supernova 1987A) are presented. No periodicity is found at significant level in these data. The complete power spectrum of four segments of data from Cygnus X-3 showing a signal near to 12.59 ms are also shown. The final chapter considers theoretical models developed previously for more massive systems accounting for the different physical scenario of these low mass systems. The process of pair production between high energy photons and the radiation field of the accretion disc appears as the tightest constraint on how close to the neutron star high energy photons can be produced

A candidate gamma-ray pulsar in the supernova remnant CTA 1

We present a detailed analysis of the high energy gamma-ray source 2EG J0008+7307. The source has a steady flux and a hard spectrum, softening above 2 GeV. The properties of the gamma-ray source are suggestive of emission from a young pulsar in the spatially coincident CTA 1 supernova remnant, which has recently been found to have a non-thermal X-ray plerion. Our 95% uncertainty contour around the >1 GeV source position includes the point-like X-ray source at the centre of the plerion. We propose that this object is a young pulsar and is the most likely counterpart of 2EG J0008+7307.Comment: Accepted for publication in MNRAS. 6 pages including four PS figures. Uses mn.te

TeV neutrinos from microquasars in compact massive binaries

We consider a compact binary system in which a Wolf-Rayet star supplies matter onto a stellar mass black hole or a neutron star. This matter forms an accretion disk which ejects a jet as observed in Galactic microquasars. A part of the jet kinetic energy, typically 10%, can be transfered to relativistic nuclei. These nuclei lose nucleons as a result of photo-disintegration process in collisions with thermal photons from the accretion disk and the massive star. Due to the head on photon-nucleus collisions most of neutrons released from nuclei move towards the surface of the accretion disk and/or the massive star producing neutrinos in collisions with the matter. We calculate the spectra of muon neutrinos and expected neutrino event rates in a 1 km^2 neutrino detector of the IceCube type from a microquasar inside our Galaxy applying, as an example, the parameters of the Cyg X-3 binary system, provided that nuclei are accelerated to the Lorentz factors above 10^6 with the power law spectrum with an index close to 2.Comment: 13 pages, 2 figures, ApJ, accepte