Now showing items 1-20 of 22

    • Compatibility of the large quasar groups with the concordance cosmological model 

      Marinello, Gabriel E.; Clowes, Roger G.; Campusano Brown, Luis; Williger, Gerard M.; Sochting, Ilona K.; Graham, Matthew J. (2016)
      We study the compatibility of large quasar groups with the concordance cosmological model. Large quasar groups are very large spatial associations of quasars in the cosmic web, with sizes of 50-250 h(-1) Mpc. In particular, ...
    • Cusps in the center of galaxies: a real conflict with observations or a numerical artefact of cosmological simulations? 

      Baushev, Anton; Valle Bertoni, Luciano del; Campusano Brown, Luis; Escala Astorquiza, Andrés; Muñoz Vidal, Ricardo; Palma Quilodrán, Gonzalo (IOP Publishing, 2017-05)
      Galaxy observations and N-body cosmological simulations produce conflicting dark matter halo density pro files for galaxy central regions. While simulations suggest a cuspy and universal density pro file (UDP) of this ...
    • Delaunay based algorithm for finding polygonal voids in planar point sets 

      Alonso, R.; Ojeda, J.; Hitschfeld Kahler, Nancy; Hervías, C.; Campusano Brown, Luis (Elsevier, 2018)
      This paper presents a new algorithm to find under-dense regions called voids inside a 2D point set. The algorithm starts from terminal-edges (local longest-edges) in a Delaunay triangulation and builds the largest possible ...
    • A delaunay Tessellation based void finder algorithm 

      Alonso Ortega, Rodrigo Ignacio (Universidad de Chile, 2016)
      En el campo de la cosmología, los vacíos son regiones del espacio cuya densidad es nota- blemente menor que la densidad de fondo, abarcando distancias en el rango de 20 50 Mpc/h (1 Mpc/h ∼ 2,10 × 1019 km). Los primeros ...
    • Dry merger rate and post-merger fraction in the Coma cluster core 

      Cordero, Juan P.; Campusano Brown, Luis; Propris, Roberto de; Haines, Chris; Weinzirl, Tim; Jogee, Shardha (The American Astronomical Society, 2016)
      A We evaluate the dry merger activity in the Coma cluster, using a spectroscopically complete sample of 70 red-sequence (RS) galaxies, most of which (similar to 75%) are located within 0.2R(200) (similar to 0.5 Mpc) from ...
    • Environments of strong/ultrastrong, ultraviolet Fe II emitting quasars 

      Clowes, Roger G.; Raghunathan, Srinivasan; Söchting, Ilona K.; Graham, Matthew J.; Campusano Brown, Luis (Oxford University Press, 2013-06)
      We have investigated the strength of ultraviolet (UV) Fe II emission from quasars within the environments of large quasar groups (LQGs) in comparison with quasars elsewhere, for 1.1 ≤ ¯zLQG ≤ 1.7, using the DR7QSO catalogue ...
    • La era inflamatoria del universo en teorias de bigravedad: perspectivas teóricas y observacionales 

      Atal Chomali, Vicente (Universidad de Chile, 2012)
      Este trabajo representa un primer intento para unir el paradigma inflacionario con teorías de bigravedad. Por una parte, inflación es un período hipotético dentro de la historia del Universo durante del cual el Universo ...
    • Experimental and theoretical challenges in the search for tensor B-modes 

      Raghunathan, Srinivasan (Universidad de Chile, 2016)
      This thesis describes the work that I performed to analyse the data from the Atacama B-mode Search (ABS) experiment. The ABS experiment observed the Cosmic Microwave Background (CMB) radiation for three years using ...
    • Galaxy Cluster Detection using Nonparametric Maximum Likelihood Estimation of Features in Voronoi Tessellations 

      Pizarro Pizarro, Daniel Iván (Universidad de ChilePrograma Cybertesis, 2007)
    • Monitoreo Óptico de Causares Luminosos de Alto Redshift 

      Botti Rojas, Ismael Andrés (Universidad de ChileCyberDocs, 2011)
    • Paralelización de un Algoritmo para la Detección de Cúmulos de Galaxias 

      Augsburger Becerra, Marcel Andre (Universidad de ChileCyberDocs, 2012)
      Dados los avances en la tecnología, la astronomía es capaz de recolectar del orden de terabytes de datos por noche. El análisis manual de ésta es prácticamente imposible, por lo que es constante la necesidad de nuevos y ...
    • Properties of high-Z galaxies seen through lensing clusters 

      Pelló, R.; Bolzonella, M.; Campusano Brown, Luis; Dantel Fort, M.; Fort, B.; Kneib, J. P.; Le Borgne, J. F.; Mellier, Y.; Ellis, R. S.; Smail, I. (2001)
      We present new results obtained on the identification and study of high-z galaxies seen through lensing clusters used as gravitational telescopes. The amplification effect provides a tool to study the spectrophotometric ...
    • Propiedades de aglomeración de galaxias normales y activas A z ~ 3 en la exploración musyc 

      Francke Henriquez, Harold (Universidad de Chile, 2009)
      Las observaciones de galaxias a corrimientos al rojo menores que 1 (z < 1) han mostrado que durante los últimos 8 giga-años de existencia del universo, las propiedades generales de las galaxias se mantienen parecidas a las ...
    • Quasar environment in the context of large-scale structure at z similar to 0.3 

      Söchting, Ilona K.; Clowes, Roger G.; Campusano Brown, Luis (2002)
      We look at quasar environment in the context of large-scale structure (LSS) – a new approach, giving a more informed interpretation of quasar–galaxy correlations. This paper presents our first results for a sample of z ...
    • Re-assessment of the large scale structure in the 2dF galaxy redshift survey 

      Marinello Batalla, Gabriel Esteban Eugenio (Universidad de Chile, 2011)
      La distribución de galaxias a gran escala define una compleja red de filamentos, murallas y vacíos de galaxias, situándose los cúmulos de galaxias en la intersección de filamentos. A dicha red se la conoce como “Estructura ...
    • Relation of radio-quiet quasars to galaxy clusters at z < 0.3 

      Söchting, Ilona K.; Clowes, Roger G.; Campusano Brown, Luis (2004)
      We investigate whether radio-quiet quasars (RQQs) with z < 0.3 (and predominantly of low luminosity) are located preferentially in specific regions with respect to the centres and boundaries of neighbouring galaxy clusters. ...
    • Self interactive dark matter in large scale structure 

      Rincón Rivero, Ángel (Universidad de Chile, 2016)
      Cold Dark matter (ΛCDM) models have been remarkably successful to explain the observed large scale structure of our universe on scales of the order of galaxy clusters (≥ 4 Mpc) and above (therefore in this work we consider ...
    • Strong lensing in the inner halo of galaxy clusters 

      Sáez, C.; Campusano Brown, Luis; Cypriano, E. S.; Sodre, L.; Kneib, J. P. (Oxford Univ. Press, 2016)
      We present an axially symmetric formula to calculate the probability of finding gravitational arcs in galaxy clusters, being induced by their massive dark matter haloes, as a function of clusters redshifts and virial masses. ...
    • A structure in the early Universe at z similar to 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology 

      Clowes, Roger G.; Harris, Kathryn A.; Raghunathan, Srinivasan; Campusano Brown, Luis; Söchting, Ilona K.; Graham, Matthew J. (Oxford University Press on behalf of the Royal Astronomical Society, 2013-03)
      A large quasar group (LQG) of particularly large size and high membership has been identified in the DR7QSO catalogue of the Sloan Digital Sky Survey. It has characteristic size (volume(1/3)) similar to 500 Mpc (proper ...
    • Ultra Deep Catalogue of Galaxy Structures in the Cosmic Evolution Survey field 

      Söchting, Ilona K.; Coldwell, Georgina V.; Clowes, Roger G.; Campusano Brown, Luis; Graham, Matthew J. (Royal Astronomical Society, 2012-04-03)
      detected using a fully automated search in the Cosmic Evolution Survey field. The detection algorithm is based on density peak extraction from a density distribution sampled usingVoronoi tessellation within overlapping ...