Feedback-limited Accretion: Luminous Signatures from Growing Planets

Planets form in discs of gas and dust around stars, and keep growing by accretion of disc material while available. Massive planets clear a gap in that protoplanetary disc, but still accrete through spiral wakes. On its way to the planet, the gas will settle on a \emph{circumplanetary} disc around the planet and slowly accrete on to it. The energy of the accreted gas will be released, heating the planet surroundings in a feedback process. For high enough accretion rates the planet should be detectable at infrared wavelengths. We aim to find whether detectable planet luminosities, $\gtrsim 10^{-3} \, \textrm{L}_\odot$, can occur when considering that the planet luminosity is coupled to the accretion, and also to study which other effects has the feedback on the dynamics of the circumplanetary and the gap regions. We model a planet with mass ratio $q=10^{-3}$, orbiting at 10 AU from a solar mass star, using a modified version of the 2D code FARGO-AD, which includes a prescription for the accretion and feedback luminosity of the planet. We find that the planetary feedback is able to partially deplete the circumplanetary disc, and to reduce the accretion rate onto the planet. However, detectable luminosities of $L_\textrm{p}\gtrsim 10^{-3}\, \textrm{L}_\odot$ are still produced. The feedback also contributes to partially refilling the gap, to heat up the coorbital region, and to perturb the orbital velocity of the gas.Comment: Submitted to MNRA

Interpretación de la toponimia vasca

Alfabetización de las listas de toponimia vascas realizadas por Sabino Arana, Eleizalde y Etxalar. Se da la bibliografía referida a las toponimiasTranscription of the lists of Basque toponimy carried out by Sabino Arana, Eleizalde and Etxalar. Bibliography referred to the toponimies is provide

Protoplanetary disk dynamics in high dust-to-gas ratio environments

Protoplanetary disks are the birthplace of planets. Gas and dust orbit around the central star subject to the forces of gravity, pressure, turbulence, and mutual drag. With the advent of the new telescopes, we need more than ever accurate models to interpret the observations of disks, which display a wide variety of substructures. In this work we study the effect of the mutual drag force between gas and dust on protoplanetary disk dynamics and evolution, particularly in the cases where the dust-to-gas ratio is high enough for the solids to become dynamically important. We derive the collective gas and dust dynamics from the momentum conservation equations, by including the back-reaction from the dust to the gas drag force, and considering the contribution of multiple dust species. The resulting velocities are implemented into the protoplanetary disk evolution codes Dustpy and Twopoppy, that solve the advection of the gas and dust components of the protoplanetary disk, along with the growth of solids through coagulation and fragmentation. Finally, we combine our equations for the fluid dynamics with different disk scenarios, including: the re-activation of a dead zone, the evaporation and condensation of water at the snowline, and the evolution of a photo-evaporative disk. We characterize the effect of dust back-reaction on the gas and dust dynamics in the different scenarios. We find that in the event of a dead zone re-activation the high dust content accumulated in the inner regions damps the collective disk motion, since more material is carried away by the same viscous force. At the snowline the dust back-reaction can stop the gas flow, disconnect the inner and outer disk in terms of gas accretion, and enhance both the radial extend and the level concentration of dust accumulations. Also, dust rings formed at the edge of a photo-evaporative gap are spread over a wider area, since the dust back-reaction smooths the gas pressure profile by pushing the material away from the pressure maximum. Lastly, we find that the back-reaction only affects the disk motion in environments with high dust-to-gas ratios, low turbulent viscosity, and large particle sizes. Our work shows the effects of the the dust back-reaction on the global disk dynamics, and can be used to better characterize observational signatures, by providing a more accurate model for the dust distribution, as well as a guideline to assess whether the dust back-reaction should be considered, given the disk conditions

Los dioscuros de Carolina V. Humboldt y el Palacio de la Granja por G. von Humboldt

El artículo reune fragmentos del viaje realizado a España por Guillermo de Humboldt entre 1799-1800, más concretamente recoge su estancia en Segovia, acompañado de su mujer Catalina, y su visita al palacio de la Granja. Catalina escribió un artículo a su hermano contándole sus impresiones acerca de un magnífico grupo escultórico que ha visto en la Granja: el grupo de Cástor y Pollu

Sufijos locativos

Lista alfabética de sufijos toponímicos con varios ejemplos. Se analizan las derivaciones de los sufijos, por ejemplo, considera que "-ao" deriva de "-ano" o "-aun", "-eun" o "-ain" y no es un diminutivo como afirman otros. El sufijo "-anda" puede ser una variante de "-ana"Alphabetical list of toponimic suffixes with several examples. The author analyzes the derivations of the suffixes, for example, he considers that "-ao" is derived from "-anus" or "-aun", "-eun" or "-ain", which is not a diminutive as other authors assert. The suffix "-anda" can be a variant of "-ana

El comic como lenguaje artístico reconocible, crítica y político de lo social

El interés de este proyecto artístico está encaminado a la investigación sobre la asimilación inconsciente de la violencia por parte del individuo a través de los Máss Media, debido a que en esta época globalizada en la cual vivimos estamos llenos de información, la misma que receptamos por medio de la escuela, la televisión, radio, prensa, internet, cine, etc. de todo este bombardeo de información al cual estamos expuestos, la de mayor rango de asimilación es la de carácter grafico; y esta mayormente es de carácter violento Dentro de todo este contexto cultural nos damos cuenta que vivimos en una sociedad llena de violencia, en la cual hemos llegado acostumbrarnos a la misma, debido a que en el día a día, estamos expuestos a la violencia, ya sea de carácter verbal, o la misma discriminación de las clases sociales que son una forma de violencia. Dentro de este contexto mi propuesta artística consiste, en la utilización de un medio de comunicación y entretenimiento de masas como es el comic, debido a su simplicidad en la asimilación del discurso por parte del receptor, para de esta manera, no solo poder llegar a un público menos preparado con respecto al arte contemporáneo, sino también revalorizar este medio de expresión artística.Licenciado en Artes VisualesCuenc

The Visit de Merle Collins y The Bed Sitting Room de Maureen Ismay: dos aproximaciones al tema del desplazamiento en la literatura post-colonial

[Abstract] This paper seeks to analyse how the theme of displacement, a key issue in Post-Colonial literature, is dealt with in two short stories by two Caribbean female writers, that is, Merle CoUin's "The Visit" and Maureen Ismay's "The Bed Sitting Room". In both stories, seve- ral thematic motifs, especially gender, race and language, intertwine in the depiction of the feeling of displacement of the female protagonists and their quest for a new identity. The ten- sion mother --daughter, metropolis- colony, self -home, also adds to the representation of this dislocation. Though coinciding in certain aspects, the different origin of the displace- ment of the female protagonists will be reflected in the different solution to the conflict of the los s of identity through the recovery of a new relationship between self and place tqat each story portrays