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On the Nature of Fossil Galaxy Groups: Are they really fossils ?
F. La Barbera, R. R. de Carvalho, I. G. de la Rosa +3
We use SDSS-DR4 photometric and spectroscopic data out to redshift z~0.1 combined with ROSAT All Sky Survey X-ray data to produce a sample of twenty-five fossil groups (FGs), defin…
Properties of Galaxies Hosting X-ray Selected Active Galactic Nuclei in the Cl1604 Supercluster at z=0.9
Dale D. Kocevski, Lori M. Lubin, Brian C. Lemaux +4
To investigate the role of feedback from Active Galactic Nuclei (AGN) in driving the evolution of their host galaxies, we have carried out a study of the environments and optical p…
The Observations of Redshift Evolution in Large Scale Environments (ORELSE) Survey : I. The Survey Design and First Results on Cl 0023+0423 at z = 0.84 and RX J1821.6+6827 at z = 0.82
L. M. Lubin, R. R. Gal, B. C. Lemaux +2
We present the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey, a systematic search for structure on scales greater than 10 Mpc around 20 well-known…
Chandra Observations of the Cl1604 Supercluster at z=0.9: Evidence for an Overdensity of Active Galactic Nuclei
Dale D. Kocevski, Lori M. Lubin, Roy Gal +3
We present the results of Chandra observations of the Cl1604 supercluster at z~0.9. The system is the largest structure mapped at redshifts approaching unity, containing at least e…
2DPHOT: A Multi-purpose Environment for the Two-dimensional Analysis of Wide-field Images
F. La Barbera, R. R. de Carvalho, J. L. Kohl-Moreira +5
We describe 2DPHOT, a general purpose analysis environment for source detection and analysis in deep wide-field images. 2DPHOT is an automated tool to obtain both integrated and su…
X-ray Galaxy Clusters in NoSOCS: Substructure and the Correlation of Optical and X-ray Properties
P. A. A. Lopes, R. R. de Carvalho, H. V. Capelato +5
We present a comparison of optical and X-ray properties of galaxy clusters in the northern sky. We determine the recovery rate of X-ray detected clusters in the optical as a functi…
Optical Detection of Galaxy Clusters
Roy R. Gal
This chapter provides an overview of past and present techniques for optical detection of galaxy clusters. It follows the progression of cluster detection techniques through time,…
Closing in on a Short-Hard Burst Progenitor: Constraints from Early-Time Optical Imaging and Spectroscopy of a Possible Host Galaxy of GRB 050509b
J. S. Bloom, J. X. Prochaska, D. Pooley +25
The localization of the short-duration, hard-spectrum GRB 050509b was a watershed event. Thanks to the nearly immediate relay of the GRB position by Swift, we began imaging the GRB…
Color Gradients in Early-type Galaxies: Dependence on Environment and Redshift
F. La Barbera, R. R. de Carvalho, R. Gal +4
Color gradients in early-type galaxies contain valuable clues about their formation and evolutionary histories and mechanisms. We examine color gradients in 1,700 early-type galaxi…
A Catalog of Distant Compact Groups Using DPOSS
R. R. de Carvalho, T. S. Goncalves, A. Iovino +3
In this paper we present an objectively defined catalog of 459 small, high density groups of galaxies out to z~0.2 in a region of 6260 square degrees in the northern sky derived fr…
Pushing the Boundaries of the Cl 1604 Supercluster at z~0.9
R. R. Gal, L. M. Lubin, G. K. Squires
The Cl 1604 supercluster at z~0.9 is known to contain at least four distinct member clusters, separated in both projection and redshift. In this paper we present deep, multicolor w…
Galaxy Groups Associated with Gravitational Lenses and H_0 from B1608+656
Chris Fassnacht, Lori Lubin, John McKean +6
Compact groups of galaxies recently have been discovered in association with several strong gravitational lens systems. These groups provide additional convergence to the lensing p…
The Northern Sky Optical Cluster Survey IV: An Intermediate Redshift Galaxy Cluster Catalog and the Comparison of Two Detection Algorithms
P. A. A. Lopes, R. R. de Carvalho, R. R. Gal +4
We present an optically selected galaxy cluster catalog from ~ 2,700 square degrees of the Digitized Second Palomar Observatory Sky Survey (DPOSS), spanning the redshift range 0.1…
The Second Data Release of the Sloan Digital Sky Survey
K. Abazajian et al.
The Sloan Digital Sky Survey has validated and made publicly available its Second Data Release. This data release consists of 3324 square degrees of five-band (u g r i z) imaging d…
Peculiar Broad Absorption Line Quasars found in DPOSS
Robert J. Brunner, Patrick B. Hall, S. George Djorgovski +10
With the recent release of large (i.e., > hundred million objects), well-calibrated photometric surveys, such as DPOSS, 2MASS, and SDSS, spectroscopic identification of important t…
A New Sample of Distant Compact Groups From DPOSS
A. Iovino, R. de Carvalho, R. Gal +4
We have identified eighty-four small, high density groups of galaxies out to z ~ 0.2 in a region of ~ 2000 square degrees around the north galactic pole using DPOSS (the Digitized…
The Digitized Second Palomar Observatory Sky Survey (DPOSS) II: Photometric Calibration
R. R. Gal, R. R. de Carvalho, S. C. Odewahn +4
We present the photometric calibration technique for the Digitized Second Palomar Observatory Sky Survey (DPOSS), used to create seamless catalogs of calibrated objects over large…
Searches for Rare and New Types of Objects
S. G. Djorgovski, A. A. Mahabal, R. J. Brunner +4
Systematic exploration of the observable parameter space, covered by large digital sky surveys spanning a range of wavelengths, will be one of the primary modes of research with a…
Exploring the Multi-Wavelength, Low Surface Brightness Universe
R. J. Brunner, S. G. Djorgovski, R. R. Gal +2
Our current understanding of the low surface brightness universe is quite incomplete, not only in the optical, but also in other wavelength regimes. As a demonstration of the type…
Groups and clusters detection on DPOSS catalogs
E. Puddu, E. De Filippis, V. Strazzullo +5
We discuss the implementation and validation of a procedure aimed to detect groups and clusters of galaxies in DPOSS catalogs.
Mass-to-Light Ratios of Groups and Clusters of Galaxies
V. Hradecky, C. Jones, R. H. Donnelly +3
We constrain the mass-to-light ratios, gas mass fractions, baryon mass fractions and the ratios of total to luminous mass for a sample of eight nearby relaxed galaxy groups and clu…
The Palomar Abell Cluster Optical Survey I: Photometric Redshifts for 431 Abell Clusters
R. R. Gal, R. R de Carvalho, R. Brunner +2
This paper presents photometric redshifts for 431 Abell clusters imaged as part of the Palomar Abell Cluster Optical Survey (PACOS), of which 236 are new redshi fts. We have obtain…
Tests of the Accelerating Universe with Near-Infrared Observations of a High-Redshift Type Ia Supernova
Adam G. Riess, Alexei V. Filippenko, Michael C. Liu +25
We have measured the rest-frame B,V, and I-band light curves of a high-redshift type Ia supernova (SN Ia), SN 1999Q (z=0.46), using HST and ground-based near-infrared detectors. A…
An automatic procedure to extract galaxy clusters from CRoNaRio catalogs
E. Puddu, S. Andreon, G. Longo +6
We present preliminary results of a simple peak finding algorithm applied to catalogues of galaxies, extracted from the Second Palomar Sky Survey in the framework of the CRoNaRio p…