Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

XIPE: the x-ray imaging polarimetry explorer

XIPE, the X-ray Imaging Polarimetry Explorer, is a mission dedicated to X-ray Astronomy. At the time of writing XIPE is in a competitive phase A as fourth medium size mission of ESA (M4). It promises to reopen the polarimetry window in high energy Astrophysics after more than 4 decades thanks to a detector that efficiently exploits the photoelectric effect and to X-ray optics with large effective area. XIPE uniqueness is time-spectrally-spatially- resolved X-ray polarimetry as a breakthrough in high energy astrophysics and fundamental physics. Indeed the payload consists of three Gas Pixel Detectors at the focus of three X-ray optics with a total effective area larger than one XMM mirror but with a low weight. The payload is compatible with the fairing of the Vega launcher. XIPE is designed as an observatory for X-ray astronomers with 75 % of the time dedicated to a Guest Observer competitive program and it is organized as a consortium across Europe with main contributions from Italy, Germany, Spain, United Kingdom, Poland, Sweden

The spatial distribution of Spanish transport infrastructure between 1860 and 1930

H54, L92, N73, O18,

La motivación fuerza impulsora del aprendizaje

Se quiere solucionar la indisciplina de los alumnos mediante la atención personalizada para lograr su motivación y una mayor tolerancia y respeto a la comunidad educativa. El objetivo principal es que los alumnos aprendan estrategias de mejora personal y de aprendizaje, partiendo de su conocimiento personal y adecuándolas al carácter individual de su entorno. La metodología es dinámica y participativa. Tras el análisis de los cuestionarios iniciales sobre intereses y necesidades de los alumnos, el tutor organiza los contenidos y actividades. Se exponen las técnicas, métodos y estrategias que pueden emplearse para conseguir actitudes y capacidades, se realizan ejercicios de comprensión y por último las prácticas necesarias para que el alumno se considere seguro de emplearlas. Los tutores atienden individualmente a los alumnos más problemáticos y orientan a los padres en las distintas formas de comunicarse con sus hijos. Los alumnos realizan actividades individuales o en grupo, preparan exposiciciones y elaboran un trabajo resumen del año. Se trabaja el bloque Aumenta y mejora tu conocimiento personal para que descubran sus capacidades y recursos, y ¿Qué tengo que hacer para motivarme? para lograr metas y constancia. Tras la evaluación inicial, son los propios alumnos quienes determinan cuándo y qué nivel han alcanzado y si están conformes con lo conseguido. Se incluye en el proyecto curricular de centro como Plan de Acción Tutorial.Madrid (Comunidad Autónoma). Consejería de EducaciónMadridMadrid (Comunidad Autónoma). Subdirección General de Formación del Profesorado. CRIF Las Acacias; General Ricardos 179 - 28025 Madrid; Tel. + 34915250893ES

Análisis Plural. Año 1. Número 1. Una visión diferente de la 4T

En este primer número de la revista, en su nueva versión digital, se orfece un panorama general de lo acontecido en la primera mitad de la administración de Andrés Manuel López Obrador y su denominada "Cuarta transformación" (4T).ITESO, A.C