Multiwavelength study of quiescent states of MrK 421 with unprecedented hard x-Ray coverage provided by NuStar in 2013

We present coordinated multiwavelength observations of the bright, nearby BL Lacertae object Mrk 421 taken in 2013 January–March, involving GASP-WEBT, Swift, NuSTAR, Fermi-LAT, MAGIC, VERITAS, and other collaborations and instruments, providing data from radio to very high energy (VHE) γ-ray bands. NuSTAR yielded previously unattainable sensitivity in the 3–79 keV range, revealing that the spectrum softens when the source is dimmer until the X-ray spectral shape saturates into a steep G » 3 power law, with no evidence for an exponential cutoff or additional hard components up "aprox" 80keV. For the first time, we observed both the synchrotron and the inverse-Compton peaks of the spectral energy distribution (SED) simultaneously shifted to frequencies below the typical quiescent state by an order of magnitude. The fractional variability as a function of photon energy shows a double-bump structure that relates to the two bumps of the broadband SED. In each bump, the variability increases with energy, which, in the framework of the synchrotron self-Compton model, implies that the electrons with higher energies are more variable. The measured multi band variability, the significant X-ray-toVHE correlation down to some of the lowest fluxes ever observed in both bands, the lack of correlation between optical/UV and X-ray flux, the low degree of polarization and its significant (random) variations, the short estimated electron cooling time, and the significantly longer variability timescale observed in the NuSTAR light curves point toward in situ electron acceleration and suggest that there are multiple compact regions contributing to the broadband emission of Mrk 421 during low-activity states.

Development of data reduction pipelines for GTC instruments at the UCM

The UCM Instrumentation Group (GUAIX) is developing currently Data Reduction Pipelines (DRP) for four instruments of the GTC: EMIR, FRIDA, MEGARA and MIRADAS. The purpose of the DRPs is to provide astronomers scientific quality data, removing instrumental biases, calibrating the images in physical units and providing a estimation of the associated uncertainties.

Evaluación del rendimiento de un planificador de tareas sobre una plataforma heterogénea ARM+DSP de Texas Instruments

El presente trabajo estudia la viabilidad a la hora de aplicar un modelo de programación basado en la extracción de paralelismo a nivel de tareas sobre distintas arquitecturas heterogéneas basadas en un procesador multinúcleo de propósito general acelerado con uno o más aceleradores hardware. Se ha implementado una aplicación completa cuyo objetivo es la detección de bordes en una imagen (implementando el Algoritmo de Canny), y se ha evaluado en detalle su rendimiento sobre distintos tipos de arquitecturas, incluyendo CPUs multinúcleo de última generación, sistemas multi-GPU y una arquitectura objetivo basada en procesadores ARM Cortex-A15 acelerados mediante un DSP C66x de la compañía Texas Instruments. Los resultados experimentales demuestran la viabilidad de este tipo de implementación también para arquitecturas heterogéneas novedosas como esta última, e ilustran la facilidad de programación que introduce este tipo de modelos de programación sobre arquitecturas de propósito específico.