Environmental effects on galaxy evolution. II: quantifying the tidal features in NIR-images of the cluster Abell 85

This work is part of a series of papers devoted to investigate the evolution of cluster galaxies during their infall. In the present article we imaged in NIR a selected sample of galaxies through- out the massive cluster Abell 85 (z = 0.055). We obtained (JHK) photometry for 68 objects, reaching 1 mag/arcsec^2 deeper than 2MASS. We use these images to unveil asymmetries in the outskirts of a sample of bright galaxies and develop a new asymmetry index, alpha_An, which allows to quantify the degree of disruption by the relative area occupied by the tidal features on the plane of the sky. We measure the asymmetries for a subsample of 41 large area objects finding clear asymmetries in ten galaxies, most of them being in groups and pairs projected at different clustercentric distances, some of them located beyond R500 . Combining information on the Hi-gas content of blue galaxies and the distribution of sub-structures across Abell 85, with the present NIR asymmetry analysis, we obtain a very powerful tool to confirm that tidal mechanisms are indeed present and are currently affecting a fraction of galaxies in Abell 85. However, when comparing our deep NIR images with UV-blue images of two very disrupted (jellyfish) galaxies in this cluster, we discard the presence of tidal 1 interactions down to our detection limit. Our results suggest that ram-pressure stripping is at the origin of such spectacular disruptions. We conclude that across a complex cluster like Abell 85, environment mechanisms, both gravitational and hydrodynamical, are playing an active role in driving galaxy evolution.Comment: 30 pages, 13 figures, Accepted for Publication in A

Photoelectric Properties of MOS-like Structures with Twofold SRO Films

AbstractThe optical properties of silicon rich oxide (SRO) have been deeply studied because, between other reasons, they emit an intense photoluminescence (PL) from visible to the near infrared range when excited with UV light. MOS-like structures with SRO film as the active layer have shown an enhanced conductivity under different illumination conditions. In this paper, MOS-like structures with double SRO layer were fabricated in order to have a barrier to isolate the silicon substrate from the active SRO layer. Results show that all structures have a higher current when light shines on them than that obtained under dark conditions. A possible application of this photo-effect can be used to increase the response of photodetectors and silicon solar cells

Building integration of photovoltaic solar systems in the ZAE office building in Germany

Currently, one of the major concerns worldwide is the access to safe, clean and sustainable energy. People’s current life-style and our life on this planet are subject to energy availability. Therefore, latest research projects have focused on developing ways of obtaining clean, safe and renewable energy. Solar photovoltaic energy (PV) is one of those energy sources, where electricity is directly obtained from solar radiation. This paper examines a case study showing the integration of PV modules into an office and lab building located in Erlangen, Germany. Polysun Simulation Software v.5.3 was used for simulating different types, size and location of PV modules in the building selected as case study (Vela Solaris, 2012). Results demonstrate the multiple possibilities for PV integration into buildings, and the advantages and disadvantages of every option regarding electricity production, orientation, modules dimension, aesthetics and CO2 savings. Moreover, the benefits offered to designers and clients when using specialised software during design decision stages are discussed.El acceso a energía de manera segura y constante es actualmente una de las grandes preocupaciones mundiales. La continuación de la vida humana en el planeta y de los estilos de vida actuales están sujetos a la disponibilidad energética. Desde hace varias décadas numerosas investigaciones se han concentrado en buscar fuentes de energía limpias, seguras y renovables. Una de esas fuentes es la solar fotovoltaica, a través de la cual se puede obtener electricidad a partir de la radiación solar. Aquí se presenta un caso de estudio de integración, dimensionamiento y ubicación de módulos fotovoltaicos en un edificio de oficinas y laboratorios ubicado en Erlangen, Alemania. El trabajo se realizó a través de un levantamiento arquitectónico del sitio, un modelo en 3D del edificio, un estudio de sombras y simulaciones de sistemas fotovoltaicos utilizando el programa Polysun Simulation Software v.5.3 (Vela Solaris, 2012). Los resultados obtenidos demuestran las múltiples posibilidades que existen para integrar módulos fotovoltaicos en edificios, así como las ventajas y desventajas de cada opción en términos de producción de energía, orientación, dimensiones de los paneles, estética y de ahorro de CO2. Además se demuestran las ventajas que ofrece la utilización de un software especializado para tomar decisiones de diseño con mayor certeza

Metal-THINGS: The association and optical characterization of SNRs with HI holes in NGC 6946

NGC~6946, also known as the `Fireworks' galaxy, is an unusual galaxy that hosts a total of 225 supernova remnant (SNR) candidates, including 147 optically identified with high [SII]/Ha line ratios. In addition, this galaxy shows prominent HI holes, which were analyzed in previous studies. Indeed, the connection between SNRs and HI holes together with their physical implications in the surrounding gas is worth of attention. This paper explores the connection between the SNRs and the HI holes, including an analysis of their physical link to observational optical properties inside and around the rims of the holes, using new integral field unit (IFU) data from the Metal-THINGS survey. We present an analysis combining previously identified HI holes, SNRs candidates, and new integral field unit (IFU) data from Metal-THINGS of the spiral galaxy NGC 6946. We analyze the distributions of the oxygen abundance, star formation rate surface density, extinction, ionization, diffuse ionized gas, and the Baldwin-Phillips-Terlevich classification throughout the galaxy. By analyzing in detail the optical properties of the 121 previously identify HI holes in NGC 6946, we find that the SNRs are concentrated at the rims of the HI holes. Furthermore, our IFU data shows that the star formation rate and extinction are enhanced at the rims of the holes. To a lesser degree, the oxygen abundance and ionization parameter show hints of enhancement on the rims of the holes. Altogether, this provides evidence of induced star formation taking place at the rims of the holes, whose origin can be explained by the expansion of superbubbles created by multiple supernova explosions in large stellar clusters dozens of Myr ago.Comment: Accepted by A&