1,755,853 research outputs found
Cosmic rays acceleration in SN 1006
No full textSupernova remnants are expected to be the main source of Galactic cosmic rays up to energies of about 3 PeV, provided that they transfer a significant fraction of their kinetic energy to the par- ticles. The bilateral supernova remnant SN 1006 shows bright synchrotron X-ray emission from ultrarelativistic electrons accelerated at the shock front in its northeastern and southwestern limbs. If efficient hadron acceleration occurs in these regions, we expect that it affects the shock dynamics by enhancing the shock compression ratio above the canonical value of 4. We performed a spatially resolved spectral analysis of Chandra and XMM-Newton observations of SN 1006 by measuring the density of the shocked ambient medium in narrow regions between the shock front and the con- tact discontinuity. Our results show an increase of the compression ratio up to ∼ 7 in northeastern and southwestern limbs, i.e. in regions where the ambient magnetic field is almost parallel to the shock velocity. We conclude that an efficient particle acceleration causes shock modification in quasi-parallel shocks in SN 1006. By comparing our results with state-of-the-art models, we find that SN 1006 is transferring a significant fraction of its kinetic energy to hadrons
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
1006 Extraordinaria Convocatorias
No full textConvocatorias: Jefe de Depto de Servicios Administrativos; División de Control y Ejercicio del Presupuesto; División Editorial; Depto de Control Documental; Depto de Equivalencia y Revalidación de Estudios; Depto de Promoción y Prestaciones; Depto de Control del Presupuesto, y de Depto de Control NormativoConvocatorias: Jefe de Depto de Servicios Administrativos; División de Control y Ejercicio del Presupuesto; División Editorial; Depto de Control Documental; Depto de Equivalencia y Revalidación de Estudios; Depto de Promoción y Prestaciones; Depto de Control del Presupuesto, y de Depto de Control NormativoPD
Author Recognition Image 7
No full textThis image was taken at the Author Recognition Reception March 20, 2012.https://scholarworks.gvsu.edu/author_images/1006/thumbnail.jp
1006 Extraordinaria Convocatorias
No full textConvocatorias: Jefe de Depto de Servicios Administrativos; División de Control y Ejercicio del Presupuesto; División Editorial; Depto de Control Documental; Depto de Equivalencia y Revalidación de Estudios; Depto de Promoción y Prestaciones; Depto de Control del Presupuesto, y de Depto de Control Normativ
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
