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Related papers: Increasing AGN sample completeness using long-term…

200 papers

We present a census of local active galactic nuclei (AGN) at a redshift of $z\leq0.025$ selected using the high-ionization [Ne v] $\lambda14.32\,\mu$m emission line from the Infrared Database of Extragalactic Observables from Spitzer…

Astrophysics of Galaxies · Physics 2026-03-16 S. Yassir , A. Annuar

Luminous AGNs are usually selected by their non-stellar colours or their X-ray emission. Colour selection cannot be used to select low-luminosity AGNs, since their emission is dominated by the host galaxy. Objects with low X-ray to optical…

Astrophysics of Galaxies · Physics 2009-11-13 K. Boutsia , B. Leibundgut , D. Trevese , F. Vagnetti

We use Chandra data to study the incidence and properties of Active Galactic Nuclei (AGN) in 16 intermediate redshift ($0.5 < z < 1.1$) X-ray-selected galaxy groups in the Chandra Deep Field-South. We measure an AGN fraction of $f(L_{X,H} >…

To understand the Active Galactic Nuclei (AGN) phenomenon and their impact on the evolution of galaxies, a complete AGN census is required; however, finding heavily obscured AGNs is observationally challenging. Here we use the deep and…

We investigate the possible presence of active galactic nuclei (AGN) in dwarf galaxies and other nearby galaxies to identify candidates for follow-up confirmation and dynamical mass measurements. We use the Wide-field Infrared Survey…

Astrophysics of Galaxies · Physics 2017-07-19 Francine R. Marleau , Dominic Clancy , Rebecca Habas , Matteo Bianconi

Reliably identifying active galactic nuclei (AGNs) in dwarf galaxies is key to understanding black hole demographics at low masses and constraining models for black hole seed formation. Here we present Chandra X-ray Observatory observations…

Astrophysics of Galaxies · Physics 2022-06-24 Lilikoi J. Latimer , Amy E. Reines , Kevin N. Hainline , Jenny E. Greene , Daniel Stern

We use the VST-COSMOS survey to identify, via their optical broadband variability, 30 AGN in nearby (z<0.4) dwarf (10^8 MSun < M < 10^10 MSun) galaxies. VST-COSMOS offers a 1 deg^2 survey footprint, a single visit depth of 24.6 mag and 68…

Astrophysics of Galaxies · Physics 2025-11-20 S. Kaviraj , D. De Cicco , I. Lazar , B. Bichang'a , A. E. Watkins , G. Martin , S. Koudmani

We use the multi-epoch, mid-infrared Spitzer Deep, Wide-Field Survey to investigate the variability of 474,179 objects in 8.1 deg^2 of the NDWFS Bootes field. We perform a Difference Image Analysis of the four available epochs between 2004…

We present new Chandra X-ray Observatory and Hubble Space Telescope observations of eight optically selected broad-line AGN candidates in nearby dwarf galaxies ($z<0.055$). Including archival Chandra observations of three additional…

High Energy Astrophysical Phenomena · Physics 2017-02-15 Vivienne F. Baldassare , Amy E. Reines , Elena Gallo , Jenny E. Greene

We present a large robust sample of 1503 reliable and unconfused 70microm selected sources from the multiwavelength data set of the Cosmic Evolution Survey (COSMOS). Using the Spitzer IRAC and MIPS photometry, we estimate the total infrared…

We present an analysis of near-infrared (NIR) emission-line properties, AGN diagnostics, and circumnuclear gas dynamics for 453 hard X-ray selected (14$-$195 keV) AGN from the BAT AGN Spectroscopic Survey (BASS) NIR Data Release 3 (DR3;…

We measure the clustering of X-ray, radio, and mid-IR-selected active galactic nuclei (AGN) at 0.2 < z < 1.2 using multi-wavelength imaging and spectroscopic redshifts from the PRIMUS and DEEP2 redshift surveys, covering 7 separate fields…

We present the results of a 5-8 micron spectral analysis performed on the largest sample of local ultraluminous infrared galaxies (ULIRGs) selected so far, consisting of 164 objects up to a redshift of ~0.35. The unprecedented sensitivity…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 E. Nardini , G. Risaliti , Y. Watabe , M. Salvati , E. Sani

Hard X-ray surveys are an important tool for the study of active galactic nuclei (AGN): they provide almost an unbiased view of absorption in the extragalactic population, allow the study of spectral features such as reflection and high…

High Energy Astrophysical Phenomena · Physics 2013-02-12 Loredana Bassani , M. Molina , A. Malizia , F. Panessa , R. Landi , A. Bazzano , P. Ubertini , A. J. Bird , J. B. Stephen

We present a systematic search for radio active galactic nuclei (AGNs) in dwarf galaxies using recent observations taken by the Very Large Array Sky Survey (VLASS). To select these objects, we first establish a criterion to identify…

Astrophysics of Galaxies · Physics 2024-11-25 John-Michael Eberhard , Amy E. Reines , Hansung B. Gim , Jeremy Darling , Jenny E. Greene

We present the results of a 2-epoch variability survey in the Hubble Deep Field with the goal of investigating the population of AGN to z=1. The primary data sets analyzed for galactic variability are the original HDF observations obtained…

Astrophysics · Physics 2009-11-10 Vicki L. Sarajedini , Ronald L. Gilliland , Christina Kasm

Utilizing Chandra X-ray observations in the All-wavelength Extended Groth Strip International Survey (AEGIS) we identify 241 X-ray selected Active Galactic Nuclei (AGNs, L > 10^{42} ergs/s) and study the properties of their host galaxies in…

Spectral energy distribution and its variability are basic tools for understanding the physical processes operating in active galactic nuclei (AGN). In this paper we report the results of a one-year near infra red (NIR) and optical…

High Energy Astrophysical Phenomena · Physics 2015-06-16 R. Nesci , G. Tosti , T. Pursimo , R. Ojha , M. Kadler

We assemble a sample of 733 dwarf galaxies ($M_{\ast} \le 10^{9.5} \text{M}_\odot$) with signatures of active galactic nuclei (AGN) and explore the intersection between different AGN selection techniques. Objects in our database are…

Astrophysics of Galaxies · Physics 2024-05-31 Erik J. Wasleske , Vivienne F. Baldassare