Type-II surface brightness profiles in edge-on galaxies produced by flares

Previous numerical studies had apparently ruled out the possibility that flares in galaxy discs could give rise to the apparent breaks in their luminosity profiles when observed edge-on. However the studies have not, until now, analyzed this hypothesis systematically using realistic models for the disc, the flare, and the bulge. We revisit this theme by analyzing a series of models which sample a wide range of observationally based structural parameters for these three components. We have considered realistic distributions of bulge to disc ratios, morphological parameters of bulges and discs, vertical scale heights of discs and their radial gradients defining the flare for different morphological types and stellar mass bins, based on observations. The surface brightness profiles for the face-on and edge-on views of each model were simulated to find out whether the flared disc produces a Type-II break in the disc profile when observed edge-on, and if so under what conditions. Contrary to previous claims, we find that discs with realistic flares can produce significant breaks in discs when observed edge-on. Specifically a flare with the parameters of that of the Milky Way would produce a significant break of the disc at a Rbreak of ~8.6 kpc if observed edge-on. Central bulges have no significant effects on the results. These simulations show that flared discs can explain the existence of many Type-II breaks observed in edge-on galaxies, in a range of galaxies with low-to-intermediate break strength values of -0.25<S<-0.1.Comment: Published in Astronomy & Astrophysics. 5 pages, 5 figures. Language corrections by the journal included in this new versio

Towards asteroseismology of core-collapse supernovae with gravitational-wave observations - I. Cowling approximation

Gravitational waves from core-collapse supernovae are produced by the excitation of different oscillation modes in the proto-neutron star (PNS) and its surroundings, including the shock. In this work we study the relationship between the post-bounce oscillation spectrum of the PNS-shock system and the characteristic frequencies observed in gravitational-wave signals from core-collapse simulations. This is a fundamental first step in order to develop a procedure to infer astrophysical parameters of the PNS formed in core-collapse supernovae. Our method combines information from the oscillation spectrum of the PNS, obtained through linear-perturbation analysis in general relativity of a background physical system, with information from the gravitational-wave spectrum of the corresponding non-linear, core-collapse simulation. Using results from the simulation of the collapse of a 35 $M_{\odot}$ presupernova progenitor we show that both types of spectra are indeed related and we are able to identify the modes of oscillation of the PNS, namely g-modes, p-modes, hybrid modes, and standing-accretion-shock-instability (SASI) modes, obtaining a remarkably close correspondence with the time-frequency distribution of the gravitational-wave modes. The analysis presented in this paper provides a proof-of-concept that asteroseismology is indeed possible in the core-collapse scenario, and it may serve as a basis for future work on PNS parameter inference based on gravitational-wave observations

Pericia médica y arte: la otra mirada

La Medicina es la ciencia que está más cerca del hombre. Ningún avatar sociopolítico que haya modificado su organización o su práctica ha podido alterar esta verdad esencial. En el esfuerzo experiencial que el médico debe hacer para aproximarse al hombre, objeto de su quehacer y vocación, se ve necesariamente impelido a intentar un conocimiento holístico de la condición humana, esto es: al humanismo. Y al humanismo médico le debe interesar, sin duda alguna, la actividad creadora a través del Arte, que es el genuino certificado de origen de la Humanidad

La modernización de los regadíos como estrategia de desarrollo rural en Castilla y León. Aplicación a la zona regable del Bajo Carrión

La finalidad del trabajo es el estudio, como caso práctico, de la viabilidad económico-financiera que supondría modernizar la zona regable del Bajo Carrión (Palencia). Previamente, se resumen los periodos que caracterizan la política hidráulica clásica y la nueva política del agua (Directiva Marco del Agua) derivada, entre otros factores, de la amenaza del cambio climático sobre las disponibilidades de los recursos hídricos. También se analizan las ventajas e inconvenientes del sistema tradicional de regadío frente al modernizado y los incentivos que la Comunidad Autónoma de Castilla y León otorga para su ejecución y financiación, como política que favorece el desarrollo rural. En este aspecto, se valora los resultados del Programa de Desarrollo Rural 2007-2013 que tuvo esta media en materia de incorporación de jóvenes agricultores y mayores inversiones en zonas regables ya modernizadasDepartamento de Economía AplicadaMáster en Desarrollo Económico Regional y Local y Gestión del Territori