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Related papers: Low-Luminosity AGNs at the Highest Resolution: Jet…

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We present infrared, optical, and X-ray data of 48 X-ray bright, optically dull AGNs in the COSMOS field. These objects exhibit the X-ray luminosity of an active galactic nucleus (AGN) but lack broad and narrow emission lines in their…

Understanding the evolution of accretion activity is fundamental to our understanding of how galaxies form and evolve over the history of the Universe. We analyse a complete sample of 27 radio galaxies which includes both high-excitation…

We present an analysis of the optical nuclear spectra from the active galactic nuclei (AGN) in a sample of giant low surface brightness (GLSB) galaxies. GLSB galaxies are extreme late type spirals that are large, isolated and poorly evolved…

Astrophysics of Galaxies · Physics 2017-08-23 Smitha Subramanian. , Ramya. S. , Mousumi Das. , Koshy George. , T. Sivarani , T. P. Prabhu

We have studied the host galaxies of a sample of radio-loud AGN spanning more than four decades in the energy output of the nucleus. The core sample includes 40 low-power sources (BL Lac objects) and 22 high-power sources (radio-loud…

Astrophysics · Physics 2009-11-07 Matthew O'Dowd , C. Megan Urry , Riccardo Scarpa

We present deep Near-infrared (NIR) images of a sample of 19 intermediate-redshift ($0.3<z<1.0$) radio-loud active galactic nuclei (AGN) with powerful relativistic jets ($L_{1.4GHz} >10^{27}$ WHz$^{-1}$), previously classified as…

Using the Gemini Near-InfraRed Spectrograph (GNIRS), we have assembled a complete sample of 20 K-selected galaxies at 2.0<z<2.7 with high quality near-infrared spectra. As described in a previous paper, 9 of these 20 galaxies have strongly…

We explored a sample of 545 local galaxies using data from the 3XMM-DR7 and SDSS-DR8 surveys. We carried out all analyses up to z\,$\sim$\,0.2, and we studied the relation between X/O flux ratio and accretion rate for different classes of…

Astrophysics of Galaxies · Physics 2021-07-14 Asrate Gaulle , Mirjana Pović , Dejene Zewdie

We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources of this type and omitting those with steep radio spectra. We analyse data from radio…

Accretion states, which are universally observed in stellar-mass black holes in X-ray binaries, are also anticipated in active galactic nuclei (AGN). This is the case at low luminosities, when the jet-corona coupling dominates the energy…

High Energy Astrophysical Phenomena · Physics 2021-04-28 Juan A. Fernández-Ontiveros , Teo Muñoz-Darias

The disappearance of the accretion disc in low-luminosity active galactic nuclei (LLAGN) leaves behind a faint optical nuclear continuum whose nature has been largely debated, mainly due to serious observational limitations in the IR to UV…

High Energy Astrophysical Phenomena · Physics 2023-02-01 J. A. Fernández-Ontiveros , X. López-López , A. Prieto

We present a sample of 252 broad-line Active Galactic Nuclei (BLAGNs), incorporating 171 newly identified sources, spanning a redshift interval from $z$ = 0.8 to 7.2. We have analyzed spectroscopic data from the NIRSpec instrument aboard…

Astrophysics of Galaxies · Physics 2025-12-04 Caroline Baccus , Xinfeng Xu

A new, complete sample of 14,584 broad-line AGNs at $z<0.35$ is presented, which are uncovered homogeneously from the complete database of galaxies and quasars observed spectroscopically in the Sloan Digital Sky Survey Seventh Data Release.…

Astrophysics of Galaxies · Physics 2019-07-31 He-Yang Liu , Wen-Juan Liu , Xiao-Bo Dong , Hongyan Zhou , Tinggui Wang , Honglin Lu , Weimin Yuan

We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. Our studies cover about seven orders of magnitude in accretion luminosity and the full range…

Astrophysics · Physics 2008-11-26 M. Sikora , L. Stawarz , J. -P. Lasota

In recent surveys of Radio-loud AGN, a new sub-class of objects, known as Weak-Line Radio Galaxies (WLRGs) has emerged. These radio galaxies have only weak, low-ionization optical emission lines. In the X-ray band, these objects are much…

Astrophysics · Physics 2007-05-23 Karen T. Lewis , Michael Eracleous , Rita M. Sambruna

In the last decade of Active Galactic Nuclei (AGN) monitoring programs, the Mets\"ahovi Radio Observatory detected multiple times seven powerful flaring narrow-line Seyfert 1 (NLS1) galaxies at 37 GHz. Several hypotheses have been proposed,…

This study explores the space density and properties of active galaxies to z=0.8. We have investigated the frequency and nature of unresolved nuclei in galaxies at moderate redshift as indicators of nuclear activity such as Active Galactic…

Type 2 active galactic nuclei (AGN) show signatures of accretion onto a supermassive black hole through strong, high-ionization, narrow emission lines extended on scales of 100s to 1000s of parsecs, but they lack the broad emission lines…

High Energy Astrophysical Phenomena · Physics 2022-09-21 M. Lynne Saade , Murray Brightman , Daniel Stern , Matthew A. Malkan , Javier A. Garcia

We present an estimate of the space density of Active Galactic Nuclei (AGN) at z=3. Combining deep X-ray data with Lyman Break Galaxy (LBG) colour-selection in the rest-frame UV makes for highly efficient identification of AGN in a narrow…

Astrophysics · Physics 2009-11-10 K. Nandra , E. S. Laird , C. C. Steidel

We present the first quantified, statistical map of broad-line active galactic nucleus (AGN) frequency with host galaxy color and stellar mass in nearby (0.01 < z < 0.11) galaxies. Aperture photometry and z-band concentration measurements…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jonathan R. Trump , Alexander D. Hsu , Jerome J. Fang , S. M. Faber , David C. Koo , Dale D. Kocevski

Outflows and jets launched from the nuclei of galaxies emit radio synchrotron emission that can be used to study the impact of accretion energy on the host galaxy. The decades-long baseline now enabled by large radio surveys allows us to…

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