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.

El teatro cómico de Enrique García Álvarez

Enrique García Álvarez (Madrid, 1883-1931) belonged to the group of writers who stood out in the late nineteenth century and early twentieth in what was known as “género chico”, label used to oppose this kind of theater to the dramaturgy considered serious. It was composed of brief and comic works whose intention was to generate a fun time for the spectators. Our author was one of the leading representatives and his numerous creations appeared profusely in the posters of the theaters per hour. In the twentieth century, he adapted to the new forms imposed on the scene. Despite his enormous fame at the time, nowadays Enrique García Álvarez remains completely unknown, not only in the eyes of the general public but also to the more knowledgeable circles of our literature. Studies of his dramatic work are almost nonexistent and basically limited to their collaborations with other authors who had more luck as Arniches or Muñoz Seca. The purpose of this thesis is, therefore, to complete a thorough study of the figure and production of Enrique García Álvarez, as well as its impact on the literature. The opening chapter is a reconstruction of the life and work of the author. In the following chapters, we proceeded to the analysis of structural features such as theme, time, space, and characters of his dramatic world. At the end of these pages, we have included a photographic appendix that illustrates some moments of his personal and professional career. We have also developed appendices to classify his librettos chronologically, by collaborator and by genre...