M. N. Pavlinsky

Bio: M. N. Pavlinsky is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Telescope & Gamma-ray burst. The author has an hindex of 22, co-authored 151 publications receiving 2233 citations. Previous affiliations of M. N. Pavlinsky include Space Research Institute.

The center of the Galaxy in the recent past : a view from Granat

Abstract: We present 15' resolution images of the extended source (∼1.°5) in the center of our Galaxy made with the ART-P telescope onboard Granat, in the energy bands 2.5-5 keV, 5-8.5 keV, and, for the first time, in the harder 8.5-22 keV interval. In the 2.5-8.5 keV band, we see a source of roughly the same shape as that found by Spartan 1, Spacetab 2, and Ginga. At higher energies, this source appears much more elongated parallel to the Galactic plane and has some features in common with the map of the molecular gas clouds. This leads us to suggest that part of the observed X-ray flux (at least at higher energies) may be X-rays from nearby compact sources, Thomson-scattered by dense molecular gas

Hard X-ray view of the past activity of Sgr A in a natural Compton mirror

Abstract: We report the association of the recently discovered hard X-ray source IGR J17475−2822 with the giant molecular cloud Sgr B2 in the Galactic Center region. The broad band (3-200 keV) spectrum of the source constructed from data of different observatories strongly supports the idea that the X-ray emission of Sgr B2 is Compton scattered and reprocessed radiation emitted in the past by the Sgr Asource. We conclude that 300-400 years ago Sgr Awas a low luminosity (L ≈ 1.5 × 10 39 erg s −1 at 2-200 keV) AGN with a characteristic hard X-ray spectrum (photon index Γ ≈ 1. 8). We estimate the mass and iron abundance of the Sgr B2 scattering gas at 2 × 10 6 M� (r/10 pc) 2 and 1.9 solar, respectively (where r is the radius of

Three Spectral States of 1E 1740.7-2942: From Standard Cygnus X-1 Type Spectrum to the Evidence of Electron-Positron Annihilation Feature

Abstract: The source 1E 1740.7-2942 is known to be the brightest hard X-ray source close to the dynamic center of our Galaxy. Three apparently different spectral states of this source were detected by the GRANAT observatory during 1990-1991 observations of the Galactic Center (GC) region. In almost all 1990 observations the source had Cyg X-1-like spectrum with nearly constant flux. The hardest of the states (observed on 1990 October 13-14) exhibits a prominent high-energy bump on the spectrum at 300-600 keV, probably related to the annihilation processes in relatively cold electron-positron plasma

Sigma discovery of variable e(+)-e(-) annihilation radiation from the near Galactic center variable compact source 1E 1740.7 - 2942

Abstract: A series of observations of the Galactic center have been performed by the hard X-ray and low-energy gamma-ray coded imaging telescope SIGMA, aboard the GRANAT space observatory, in 1990 march, April, September, and October, in the energy range 35 keV-1.3 MeV. The emission of the close nucleus center region above 35 keV was found to be dominated up to 300 keV by the previously observed X-ray source 1E 1740.7-2942, situated ≃48' away from the radio source Sgr A *

Parameter estimation in astronomy through application of the likelihood ratio. [satellite data analysis techniques

Abstract: Many problems in the experimental estimation of parameters for models can be solved through use of the likelihood ratio test. Applications of the likelihood ratio, with particular attention to photon counting experiments, are discussed. The procedures presented solve a greater range of problems than those currently in use, yet are no more difficult to apply. The procedures are proved analytically, and examples from current problems in astronomy are discussed.

The Supernova Gamma-Ray Burst Connection

Abstract: Observations show that at least some gamma-ray bursts (GRBs) happen simultaneously with core-collapse supernovae (SNe), thus linking by a common thread nature's two grandest explosions. We review here the growing evidence for and theoretical implications of this association, and conclude that most long-duration soft-spectrum GRBs are accompanied by massive stellar explosions (GRB-SNe). The kinetic energy and luminosity of well-studied GRB-SNe appear to be greater than those of ordinary SNe, but evidence exists, even in a limited sample, for considerable diversity. The existing sample also suggests that most of the energy in the explosion is contained in nonrelativistic ejecta (producing the supernova) rather than in the relativistic jets responsible for making the burst and its afterglow. Neither all SNe, nor even all SNe of Type Ibc produce GRBs. The degree of differential rotation in the collapsing iron core of massive stars when they die may be what makes the difference.

Cosmology and Fundamental Physics with the Euclid Satellite

Abstract: Euclid is a European Space Agency medium-class mission selected for launch in 2020 within the cosmic vision 2015–2025 program. The main goal of Euclid is to understand the origin of the accelerated expansion of the universe. Euclid will explore the expansion history of the universe and the evolution of cosmic structures by measuring shapes and red-shifts of galaxies as well as the distribution of clusters of galaxies over a large fraction of the sky. Although the main driver for Euclid is the nature of dark energy, Euclid science covers a vast range of topics, from cosmology to galaxy evolution to planetary research. In this review we focus on cosmology and fundamental physics, with a strong emphasis on science beyond the current standard models. We discuss five broad topics: dark energy and modified gravity, dark matter, initial conditions, basic assumptions and questions of methodology in the data analysis. This review has been planned and carried out within Euclid’s Theory Working Group and is meant to provide a guide to the scientific themes that will underlie the activity of the group during the preparation of the Euclid mission.

The tenth data release of the Sloan digital sky survey: First spectroscopic data from the SDSS-iii apache point observatory galactic evolution experiment

Abstract: The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the Tenth Public Data Release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R ~ 22,500 300 fiber spectrograph covering 1.514-1.696 μm. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included. DR10 also roughly doubles the number of BOSS spectra over those included in the Ninth Data Release. DR10 includes a total of 1,507,954 BOSS spectra comprising 927,844 galaxy spectra, 182,009 quasar spectra, and 159,327 stellar spectra selected over 6373.2 deg2.