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PAH Emission and Star Formation in the Host of the z ~ 2.56 Cloverleaf QSO

Description: This article reports the first detection of the 6.2 and 7.7 μm infrared polycyclic aromatic hydrocarbon emission features in the spectrum of a high-redshift QSO, from the Spitzer IRS spectrum of the Cloverleaf lensed QSO.
Date: March 30, 2007
Creator: Lutz, Dieter; Sturm, Eckhard; Tacconi, Linda; Valiante, Elisabetta; Schweitzer, Mario; Netzer, Hagai et al.
Partner: UNT College of Arts and Sciences

The X-Ray Properties of the Most Luminous Quasars From the Sloan Digital Sky Survey

Description: This article studies the X-ray properties of a representative sample of 59 of the most optically luminous quasars in the universe spanning a redshift range of z ≈ 1.5-4.5.
Date: May 18, 2007
Creator: Just, Dennis W.; Brandt, William Nielsen; Shemmer, Ohad; Steffen, Aaron; Schneider, Donald P.; Chartas, George et al.
Partner: UNT College of Arts and Sciences

Erratum: "Is there a metallicity-luminosity relationship in active galactic nuclei? The case of narrow-line Seyfert 1 galaxies"

Description: This erratum corrects a computational error affecting the calculation of the intrinsic luminosities of several objects in the article "Is there a metallicity-luminosity relationship in active galactic nuclei? The case of narrow-line Seyfert 1 galaxies." This does not affect any of the main results of the article.
Date: April 10, 2002
Creator: Shemmer, Ohad & Netzer, Hagai
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

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 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

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

GRB 060505: A Possible Short-Duration Gamma-Ray Burst in a Star-Forming Region at a Redshift of 0.09

Description: This article reports the discovery of the GRB optical afterglow and observations of its environment using Gemini South, the Hubble Space Telescope, Chandra, Swift, and the Very Large Array.
Date: March 13, 2007
Creator: Ofek, Efran; Cenko, Brad; Gal-Yam, Avishay; Fox, Derek B.; Nakar, Ehud; Rau, Arne et al.
Partner: UNT College of Arts and Sciences

The Hard X-Ray Spectrum as a Probe for Black Hole Growth in Radio-Quiet Active Galactic Nuclei

Description: This article studies the hard X-ray spectral properties of 10 highly luminous radio-quiet active galactic nuclei at z = 1.3-3.2, including new XMM-Newton observations of four of these sources.
Date: April 3, 2008
Creator: Shemmer, Ohad; Brandt, William Nielsen; Netzer, Hagai; Maiolino, Roberto & Kaspi, Shai
Partner: UNT College of Arts and Sciences

The X-ray Spectral Properties and Variability of Luminous High-Redshift Active Galactic Nuclei

Description: This article contains a detailed investigation of moderate- to high-quality X-ray spectra of 10 of the most luminous active galactic nuclei known at z > 4.
Date: May 20, 2005
Creator: Shemmer, Ohad; Brandt, William Nielsen; Vignali, Christian; Schneider, Donald P.; Fan, Xiaohui; Richards, Gordon T. et al.
Partner: UNT College of Arts and Sciences