English
Related papers

Related papers: A Search for Binary Active Galactic Nuclei: Double…

200 papers

We have combined a sample of 44984 quasars, selected from the Sloan Digital Sky Survey (SDSS) Data Release 3, with the FIRST radio survey. Using a novel technique where the optical quasar position is matched to the complete radio…

Astrophysics · Physics 2009-11-11 W. H. de Vries , R. H. Becker , R. L. White

This is the first paper in a dedicated series to study the properties of the optically selected BLR-less AGNs (Active Galactic Nuclei with no-hidden central broad emission line regions). We carried out a systematic search for the BLR-less…

Astrophysics of Galaxies · Physics 2015-06-17 Xue Guang Zhang

We study the FeII properties of double-peaked broad low-ionization emission line AGN (dbp emitters) using a sample of 27 dbp emitters from SDSS (DR4), with mean value $\sigma_{H\alpha_{B}}\sim3002\pm139{\rm km\cdot s^{-1}}$. Our first…

Astrophysics · Physics 2007-05-23 Xue-Guang Zhang , Dultzin-Hacyan Deborah , Ting-Gui Wang

We present optical spectroscopy of a sample of 77 luminous AGN and quasars selected on the basis of their mid-infrared colors. Our objects are selected from the Spitzer Extragalactic First Look Survey and SWIRE XMM-LSS fields, with a…

Astrophysics · Physics 2008-11-26 M. Lacy , A. Petric , A. Sajina , G. Canalizo , L. J. Storrie-Lombardi , L. Armus , D. Fadda , F. R. Marleau

Active Galactic Nuclei (AGNs) are among the most luminous objects in the universe, making them valuable probes for studying galaxy evolution. However, understanding how AGN properties evolve over cosmic time remains a fundamental challenge.…

Astrophysics of Galaxies · Physics 2025-05-06 Shreya Sareen , Swayamtrupta Panda

In this work, we use ~500 low-redshift (z ~ 0.1) X-ray AGNs observed by XMM-Newton and SDSS to investigate the prevalence and nature of AGNs that apparently lack optical emission lines (``optically dull AGNs''). Although 1/4 of spectra…

Astrophysics of Galaxies · Physics 2023-02-15 Christopher J. Agostino , Samir Salim , Sara L. Ellison , Robert W. Bickley , S. M. Faber

Over the last few years, optical, mid-infrared and X-ray surveys have brought to light a significant number of candidate obscured AGN and, among them, many Type 2 quasars, the long-sought after "big cousins'' of local Seyfert 2 galaxies.…

Astrophysics · Physics 2007-05-23 C. Vignali , A. Comastri , D. M. Alexander

The quest for binary and dual supermassive black holes (SMBHs) at the dawn of the multi-messenger era is compelling. Detecting dual active galactic nuclei (AGN) -- active SMBHs at projected separations larger than several parsecs -- and…

We present an analysis of a large sample of AGN environments at z~1 using stacked Spitzer data at 3.6um. The sample contains type-1 and type-2 AGN in the form of quasars and radio galaxies, and spans a large range in both optical and radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 J. T. Falder , J. A. Stevens , Matt J. Jarvis , M. J. Hardcastle , M. Lacy , R. J. McLure , E. Hatziminaoglou , M. J. Page , G. T. Richards

We report on 293 quasars with strong NIV] lambda 1486 or NIII] lambda 1750 emission lines (rest-frame equivalent width > 3 \AA) at 1.7 < z < 4.0 selected from the Sloan Digital Sky Survey (SDSS) Fifth Data Release. These nitrogen-rich…

Astrophysics · Physics 2009-06-23 Linhua Jiang , Xiaohui Fan , M. Vestergaard

Interactions between the radio jet and the optical emission of the narrow-line region (NLR) are a well known phenomenon in Seyfert galaxies. Here, we present the study of possible jet-NLR interactions in five radio-quiet PG quasars with…

Astrophysics · Physics 2009-11-11 Christian Leipski , Nicola Bennert

Some Active Galactic Nuclei (AGN) host outflows which have the potential to alter the host galaxy's evolution (AGN feedback). These outflows have been linked to enhanced radio emission. Here we investigate the connection between…

Short millimeter observations of radio-loud AGN offer the opportunity to study the physics of their inner relativistic jets, from where the bulk millimeter emission is radiated. Millimeter jets are significantly less affected by Faraday…

Astrophysics of Galaxies · Physics 2014-07-02 I. Agudo , C. Thum , J. L. Gomez , H. Wiesemeyer

Pairs of galaxies hosting active galactic nuclei (AGN) are powerful probes of merger-driven supermassive black hole (SMBH) growth as they can resolve individual AGN and trace mergers over a large range of physical separations. To exploit…

Astrophysics of Galaxies · Physics 2023-07-12 R. Scott Barrows , Julia M. Comerford , Daniel Stern , Roberto J. Assef

We study the radio properties of moderately obscured quasars over a range of redshifts to understand the role of radio activity in accretion using the Jansky Very Large Array (JVLA) at 6.0GHz and 1.4GHz. Our z~2.5 sample consists of…

Astrophysics of Galaxies · Physics 2016-08-31 Rachael M. Alexandroff , Nadia L. Zakamska , Sjoert van Velzen , Jenny E. Greene , Michael A. Strauss

Active galactic nuclei (AGN) in low surface brightness galaxies (LSBGs) have received little attention in previous studies. In this paper, we present detailed spectral analysis of 194 LSBGs from the Impey et al. (1996) APM LSBG sample which…

Astrophysics of Galaxies · Physics 2009-11-13 Lin Mei , Weimin Yuan , Xiaobo Dong

Merger events can trigger gas accretion onto supermassive black holes (SMBHs) located at the centre of galaxies, and form close pairs of AGN. The fraction of AGN in pairs offers critical insights into the dynamics of galaxy interactions,…

Combined investigations of the clustering properties of galaxies of different spectral type and high-redshift quasars strongly suggest local ellipticals to be the parent population of optically bright Active Galactic Nuclei (AGN). However,…

Astrophysics · Physics 2007-05-23 Manuela Magliocchetti