UNT Scholarly Works - 121 Matching Results

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Collective behavior and evolutionary games - An introduction

Description: This article is an introduction to a special issue in Chaos, Solitons & Fractals with the goal of attracting submissions that identify unifying principles that describe the essential aspects of collective behavior, and which thus allow for a better interpretation and foster the understanding of the complexity arising in such systems.
Date: June 2013
Creator: Perc, Matjaž & Grigolini, Paolo
Partner: UNT College of Arts and Sciences

Weak Line Quasars at High Redshift: Extremely High Accretion Rates or Anemic Broad-Line Regions?

Description: This article presents Gemini-North K-band spectra of two representative members of the class of high-redshift quasars with exceptionally weak rest-frame ultraviolet emission lines.
Date: September 8, 2010
Creator: Shemmer, Ohad; Trakhtenbrot, Benny; Anderson, Scott F.; Brandt, William Nielsen; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui et al.
Partner: UNT College of Arts and Sciences

A Population of X-Ray Weak Quasars: PHL 1811 Analogs at High Redshift

Description: This article reports the results from Chandra and XMM-Newton observations of a sample of 10 type 1 quasars selected to have unusual UV emission-line properties similar to those of PHL 1811.
Date: April 15, 2011
Creator: Wu, Jianfeng; Brandt, William Nielsen; Hall, Patrick B.; Gibson, Robert R.; Richards, Gordon T.; Schneider, Donald P. et al.
Partner: UNT College of Arts and Sciences

Variability-Selected Low-Luminosity Active Galactic Nuclei in the 4 Ms Chandra Deep Field-South

Description: This article demonstrates that the observed variability cannot be explained by X-ray Binary populations or ultraluminous X-ray sources, so the variability is most likely caused by accretion onto a supermassive black hole.
Date: January 18, 2012
Creator: Young, Monica; Brandt, William Nielsen; Xue, Yongquan; Alexander, David M.; Bauer, Franz E.; Lehmer, Bret et al.
Partner: UNT College of Arts and Sciences

On The Performance of Quasar Reverberation Mapping in the Era of Time-Domain Photometric Surveys

Description: This article quantitatively assesses, by means of comprehensive numerical simulations, the ability of broadband photometric surveys to recover the broad emission line region size in quasars under various observing conditions and for a wide range of object properties.
Date: February 2, 2014
Creator: Chelouche, Doron; Shemmer, Ohad; Cotlier, Gabriel I.; Barth, Aaron J. & Rafter, Stephen E.
Partner: UNT College of Arts and Sciences

The Ultraviolet-To-Mid-Infrared Spectral Energy Distribution of Weak Emission Line Quasars

Description: This article presents Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey quasars which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet spectra.
Date: September 23, 2011
Creator: Lane, Ryan A.; Shemmer, Ohad; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Anderson, Scott F.; Brandt, William Nielsen et al.
Partner: UNT College of Arts and Sciences

X-Ray and Multiwavelength Insights into the Nature of Weak Emission-Line Quasars at Low Redshift

Description: This article reports on the X-ray and multiwavelength properties of 11 radio-quiet quasars with weak or no emission lines identified by the Sloan Digital Sky Survey with redshift.
Date: December 9, 2011
Creator: Wu, Jianfeng; Brandt, William Nielsen; Anderson, Scott F.; Diamond-Stanic, Aleksandar M.; Hall, Patrick B.; Plotkin, Richard M. et al.
Partner: UNT College of Arts and Sciences

X-Ray Spectral Constraints for z ≈ 2 Massive Galaxies: The Identification of Reflection-Dominated Active Galactic Nuclei

Description: This article uses the 4 Ms Chandra Deep Field-South survey to place direct constraints on the ubiquity of z ≈ 2 heavily obscured active galactic nuclei.
Date: June 6, 2011
Creator: Alexander, David M.; Bauer, Franz E.; Brandt, William Nielsen; Daddi, Emanuele; Hickox, Ryan; Lehmer, Bret et al.
Partner: UNT College of Arts and Sciences

The X-Ray Properties of the Optically Brightest Mini-Bal Quasars from the Sloan Digital Sky Survey

Description: This article compiles a sample of 14 of the optically brightest radio-quiet quasars in the Sloan Digital Sky Survey Data Release 5 quasar catalog that have mini-broad absorption lines present in their spectra.
Date: September 12, 2010
Creator: Wu, Jianfeng; Brandt, William Nielsen; Comins, M.L.; Gibson, Robert R.; Shemmer, Ohad; Garmire, Gordon P. et al.
Partner: UNT College of Arts and Sciences

Locating Star-Forming Regions in Quasar Host Galaxies

Description: This article presents a study of the morphology and intensity of star formation in the host galaxies of eight Palomar-Green quasars using observations with the Hubble Space Telescope.
Date: November 5, 2013
Creator: Young, Jason E.; Eracleous, Michael; Shemmer, Ohad; Netzer, Hagai; Gronwall, Caryl; Lutz, Dieter et al.
Partner: UNT College of Arts and Sciences

A Statistical Relation Between the X-ray Spectral Index and Eddington Ratio of Active Galactic Nuclei in Deep Surveys

Description: This article presents an investigation into how well the properties of the accretion flow on to a supermassive black hole may be coupled to those of the overlying hot corona.
Date: May 22, 2013
Creator: Brightman, M.; Silverman, John David; Mainieri, Vincenzo; Ueda, Yoshihiro; Schramm, Malte; Matsuoka, Kenta et al.
Partner: UNT College of Arts and Sciences

The 4Ms Chandra Deep Field-South Number Counts Apportioned By Source Class: Pervasive Active Galactic Nuclei and the Ascent of Normal Galaxies

Description: This article presents cumulative and differential number-count measurements for the recently completed 4 Ms Chandra Deep Field-South survey.
Date: April 9, 2012
Creator: Lehmer, Bret; Xue, Yongquan; Brandt, William Nielsen; Alexander, David M.; Bauer, Franz E.; Brusa, Marcella et al.
Partner: UNT College of Arts and Sciences

Multiwavelength Observations of Radio-Quiet Quasars with Weak Emission Lines

Description: This article presents radio and X-ray observations, as well as optical light curves, for a subset of 26 BL Lac candidates from the Sloan Digital Sky Survey lacking strong radio emission and with z < 2.2.
Date: July 26, 2010
Creator: Plotkin, Richard M.; Anderson, Scott F.; Brandt, William Nielsen; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; MacLeod, Chelsea L. et al.
Partner: UNT College of Arts and Sciences

The Lack of Torus Emission from BL Lacertae Objects: An Infrared View of Unification with WISE

Description: This article uses data from the Wide-Field Infrared Survey Explorer to perform a statistical study on the mid-infrared properties of a large number of BL Lac objects.
Date: December 21, 2011
Creator: Plotkin, Richard M.; Anderson, Scott F.; Brandt, William Nielsen; Markoff, Sera; Shemmer, Ohad & Wu, Jianfeng
Partner: UNT College of Arts and Sciences