Cluster Galaxy Morphologies: The Relationship among Structural Parameters, Activity and the Environment

We use an approach to estimate galaxy morphologies based on an ellipticity (e) vs. Bulge-to-Total ratio (B/T) plane. We have calibrated this plane by comparing with Dressler's classifications. With the aid of our calibration, we have classified 635 galaxies in 18 Abell clusters (0.02 < z < 0.08). Our approach allowed us to recover the Kormendy's relation. We found that ellipticals and Spirals are slightly brighter than S0 in R band. As S0 bulges are brighter than spirals bulges, we believe that ram pressure is not the main mechanism to generate S0s. In our sample, cluster radio galaxies morphologies cover the range S0-E-cD and their bulges have absolutes magnitudes distributed within -21 mag < M < -24.5 mag. If we believe Ferrarese & Merrit's relation, these radio sources have 10^8-10^9 M black hole mass.Comment: Originally published in the proceedings of the conference "The Monster's Fiery Breath: Feedback in Galaxies, Groups, and Clusters", AIP Conference Proceedings, Volume 1201 edited by Sebastian Heinz and Eric Wilcots. This version contains slight modification

The Galaxy Population of Low-Redshift Abell Clusters

We present a study of the luminosity and color properties of galaxies selected from a sample of 57 low-redshift Abell clusters. We utilize the non-parametric dwarf-to-giant ratio (DGR) and the blue galaxy fraction (fb) to investigate the clustercentric radial-dependent changes in the cluster galaxy population. Composite cluster samples are combined by scaling the counting radius by r200 to minimize radius selection bias. The separation of galaxies into a red and blue population was achieved by selecting galaxies relative to the cluster color-magnitude relation. The DGR of the red and blue galaxies is found to be independent of cluster richness (Bgc), although the DGR is larger for the blue population at all measured radii. A decrease in the DGR for the red and red+blue galaxies is detected in the cluster core region, while the blue galaxy DGR is nearly independent of radius. The fb is found not to correlate with Bgc; however, a steady decline toward the inner-cluster region is observed for the giant galaxies. The dwarf galaxy fb is approximately constant with clustercentric radius except for the inner cluster core region where fb decreases. The clustercentric radial dependence of the DGR and the galaxy blue fraction, indicates that it is unlikely that a simple scenario based on either pure disruption or pure fading/reddening can describe the evolution of infalling dwarf galaxies; both outcomes are produced by the cluster environment.Comment: 28 pages, 6 figures, accepted for publication in Ap

Evolution of Cluster Ellipticals at 0.2 < z < 1.2 from Hubble Space Telescope Imaging

Two-dimensional surface photometry derived from Hubble Space Telescope imaging is presented for a sample of 225 early-type galaxies (assumed to be cluster members) in the fields of 9 clusters at redshifts $0.17 < z < 1.21$. The 94 luminous ellipticals ($M_{AB}(B)<-20$; selected by morphology alone with no reference to color) form tight sequences in the size-luminosity plane. The position of these sequences shifts, on average, with redshift so that an object of a given size at z=0.55 is brighter by $\Delta M(B)=-0.57 \pm 0.13$ mag than its counterpart (measured with the same techniques) in nearby clusters. At z=0.9 the shift is $\Delta M(B)=-0.96 \pm 0.22$ mag. If the relation between size and luminosity is universal so that the local cluster galaxies represent the evolutionary endpoints of those at high redshift, and if the size-luminosity relation is not modified by dynamical processes then this population of galaxies has undergone significant luminosity evolution since z=1 consistent with expectations based on models of passively evolving, old stellar populations.Comment: 7 pages, 3 figures, and 1 Tabl

Creer tocando

This paper analyzes the teaching-learning process applied in Singapur (country first in several studies as PISA and TIMSS). This method is based on visual elements that enhance problem ?s understanding. Our main contribution is to complement the learning process incorporating the sense of touch and manipulation as the main mode of discovering mathematics concepts in the preschool Education.En este trabajo se trata de analizar el proceso de enseñanza aprendizaje utilizado en Singapur (país con mejores resultados en diversos estudios, PISA y TIMSS) aplicado a las matemáticas. Este método se basa en elementos visuales que permiten mejorar la comprensión del problema. Nuestra aportación es complementar el proceso de aprendizaje incorporando el sentido del tacto y utilizando la manipulación como el modo principal de descubrimiento en Educación Infantil

Crecimiento Urbano y Desarrollo Sustentable en el Municipio de Miahuatlán de Porfirio Díaz, Oaxaca, en el siglo XXI

El crecimiento urbano de las ciudades se seguirá presentando en las siguientes décadas principalmente en ciudades pequeñas y medias, en el caso del municipio de Miahuatlán de Porfirio Díaz, Oaxaca, se manifiestan retos, pero también oportunidades para que exista un crecimiento urbano ordenado y controlado, con el objetivo de mejorar el bienestar de los habitantes del municipio, además de incrementar su calidad de vida. El objetivo de la investigación es analizar el crecimiento urbano y desarrollo sustentable, presentado en el siglo XXI en Miahuatlán de Porfirio Díaz, Oaxaca. El primero al mostrarse de forma desordenada dificulta y encarece el suministro de los servicios básicos como el agua potable, alumbrado público, drenaje. Por ello, es necesario contrarrestarlo con la planeación urbana y el ordenamiento territorial de las actividades humanas, lo cual dará como resultado el uso eficiente del territorio y de los recursos naturales que existen en el municipio. Por otra parte, el planteamiento del desarrollo sustentable es incipiente, ya que no existe por parte del municipio una postura de proteger las reservas naturales que existen en el territorio, hay una escasa infraestructura y equipamiento urbano como son los parques y jardines públicos, los servicios públicos básicos no son de calidad, alumbrado público, agua potable (45% de la población no cuenta con este servicio), drenaje (20% de la población carece del servicio), lo anterior con base en la Encuesta Intercensal del INEGI, 2015. El Plan Municipal de Desarrollo (2017-2019), plantea el objetivo en el tema de vivienda, “promover la calidad y acceso a la infraestructura de servicios básicos de la vivienda de la población de Miahuatlán de Porfirio Díaz”. Por mencionar dos líneas de acción: la primera, ampliar la cobertura de la infraestructura social básica como el agua, drenaje y alumbrado público, la segunda; robustecer el sistema de drenaje y agua potable mediante la construcción, rehabilitación y ampliación de la red. Además, existen problemas de movilidad y trasporte, en el municipio tenían un registro de 6 982 vehículos de motor, siendo el décimo municipio con mayor número de registros en la entidad (INEGI, 2015). Por su parte el municipio menciona en el PMD (2017-2019), tiene como objetivo: “contribuir al desarrollo económico y social del municipio con servicios de comunicación y medios de transporte suficientes y de calidad”. La estrategia menciona, hacer de los servicios de transporte y comunicación competitivos a través del incremento de los servicios y la calidad. Mientras que su línea de acción contempla la: implementación de programas para la regulación y supervisión de los servicios de transporte público del municipio. La sustentabilidad se relaciona directamente con el cuidado y conservación del ambiente de manera adecuada, consciente y racional, para lograr su uso inteligente con la finalidad de que las futuras generaciones cuenten con el mismo nivel de recursos con los que actualmente goza la generación presente en el municipio de Miahuatlán

Evolution of galactic disks in clusters and the field at 0.1<z<0.60.1 < z < 0.6 in the CNOC survey

Two-dimensional surface photometry is presented for a sample of 351 late-type galaxies with $0.12 < z < 0.65$. These objects are drawn from the Canadian Network for Observational Cosmology (CNOC) cluster survey and are either spectroscopically confirmed members of clusters at $z=0.23$ (64 galaxies), $0.43$ (45), and $0.55$ (36) or field galaxies with similar redshifts. Galaxies in the rich cluster Abell 2256 at $z=0.06$ were also analyzed with the same methods to provide a local reference point. At redshifts of (0.23, 0.43, 0.55) the disk surface brightness in cluster late-type galaxies is higher in the $B$-band by $\Delta \mu_{0}(B) =(-0.58\pm 0.12,-1.22\pm 0.17,-0.97\pm 0.2$) mag, respectively, relative to the Freeman (1970) constant surface-brightness relation; whereas disks in cluster galaxies at $z=0.06$ are consistent with that relation. Field galaxies show a progressive disk-brightening with redshift that is consistent with that seen in the cluster population. Taken together with similar measurements of early-type galaxies (Schade et al. 1996a), these results suggest that the evolution of the field and cluster galaxy populations are similar, although we emphasize that our sample of cluster galaxies is dominated by objects at large distances (up to 3 Mpc) from the dense cluster core, so that the implications of these findings with respect to the Butcher-Oemler effect and the morphology-density relation will not be clear until an analysis of galaxy properties as a function of cluster-centric distance is completed.Comment: accepted for ApJ Letters, also available at http://manaslu.astro.utoronto.ca/~carlberg/cnoc/disk