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Related papers: Properties of IR selected Active Galactic Nuclei

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We develop a new diagnostic method to classify galaxies into AGN hosts, star-forming galaxies, and absorption-dominated galaxies by combining the [O III]/Hbeta ratio with rest-frame U-B color. This can be used to robustly select AGNs in…

Recent observations have revealed an interesting active galactic nuclei (AGN) subclass that shows strong activity at large scales ($\sim1$ kpc) but weaker at small scales ($<10$ pc), suggesting a strong change in the mass accretion rate of…

Astrophysics of Galaxies · Physics 2022-10-26 J. Pflugradt , K. Ichikawa , M. Akiyama , M. Kokubo , B. Vijarnwannaluk , H. Noda , X. Chen

We introduce a new infrared diagnostic to separate galaxies on the basis of their dominant infrared emission: stellar or nuclear. The main novelty with respect to existing diagnostics, is the usage of a broad band encompassing at the same…

Astrophysics of Galaxies · Physics 2015-06-22 Dario Fadda , Giulia Rodighiero

We present X-ray and optical analysis of 188 AGN identified from 497 hard X-ray (f (2.0-8.0 keV) > 2.7x10^-15 erg cm^-2 s^-1) sources in 20 Chandra fields (1.5 deg^2) forming part of the Chandra Multi-wavelength Project. These medium depth…

We report a new sample of obscured active galactic nuclei (AGNs) selected from the XMM serendipitous source and AKARI point-source catalogs. We match X-ray sources with infrared (18 and 90 micron) sources located at |b|>10 deg to create a…

Astrophysics of Galaxies · Physics 2015-11-18 Yuichi Terashima , Yoshitaka Hirata , Hisamitsu Awaki , Shinki Oyabu , Poshak Gandhi , Yoshiki Toba , Hideo Matsuhara

We select a sample of 90 obscured (type2) AGN with 1.45<z<3.05 from the zCOSMOS-deep galaxy sample by 5 sigma-detection of the high-ionization CIV {\lambda}1549 narrow emission line. The presence of this feature in a galaxy spectrum is…

We propose a new method for identifying active galactic nuclei (AGN) in low mass ($\rm M_*\leq10^{10}M_\odot$) galaxies. This method relies on spectral energy distribution (SED) fitting to identify galaxies whose radio flux density has an…

It is known that the IR and X-ray luminosities of Active Galactic Nuclei (AGN) are correlated with L_{IR} ~ L_{X}. Moreover, the IR flux ratio between the 5.8 and 3.6 \mu m bands is a good distinguishing characteristic of AGN or AGN-like…

High Energy Astrophysical Phenomena · Physics 2013-08-08 P. Shalima , V. Jithesh , K. Jeena , R. Misra , S. Ravindranath , G. C. Dewangan , C. D. Ravikumar , B. R. S. Babu

X-rays provide a robust method in identifying AGN. However, in the high-redshift Universe, their space density is relatively low, and, in combination with the small areas covered by X-ray surveys, the selected AGN are poorly sampled. Deep…

Astrophysics of Galaxies · Physics 2025-05-21 E. Pouliasis , A. Ruiz , I. Georgantopoulos , A. Akylas , N. A. Webb , F. J. Carrera , S. Mateos , A. Nebot , M. G. Watson , F. X. Pineau , C. Motch

It remains uncertain which continuum and emission line diagnostics best indicate the bolometric powers of active galactic nuclei (AGNs), especially given the attenuation caused by the circumnuclear material and the possible contamination by…

We study the properties of a sample of 211 heavily-obscured Active Galactic Nucleus (AGN) candidates in the Extended Chandra Deep Field-South selecting objects with f_24/f_R>1000 and R-K>4.5. Of these, 18 were detected in X-rays and found…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 E. Treister , C. Cardamone , K. Schawinski , C. M. Urry , E. Gawiser , S. Virani , P. Lira , J. Kartaltepe , M Damen , E. N. Taylor , E. Le Floc'h , Stephen Justham , A. Koekemoer

We investigate the infrared contribution from supermassive black hole activity versus host galaxy emission in the mid to far-infrared (IR) spectrum for a large sample of X-ray bright active galactic nuclei (AGN) residing in dusty,…

Astrophysics of Galaxies · Physics 2019-07-02 Arianna Brown , Hooshang Nayyeri , Asantha Cooray , Jingzhe Ma , Ryan C. Hickox , Mojegan Azadi

We present a sample of 10 low-mass active galactic nuclei (AGNs) selected from the 40-month NuSTAR serendipitous survey. The sample is selected to have robust NuSTAR detections at $3 - 24$~keV, to be at $z < 0.3$, and to have optical r-band…

Over ten mid-infrared (mid-IR) and X-ray models are currently attempting to describe the nuclear obscuring material of active galactic nuclei (AGNs), but many questions remain unresolved. This study aims to determine the physical parameters…

In this study, we use the SWIFT/BAT AGN sample, which has received extensive multiwavelength follow-up analysis as a result of the BAT AGN Spectroscopic Survey (BASS), to develop a diagnostic for nuclear obscuration by examining the…

We discuss the very different methods in each wavelength band for selecting and finding Active Galactic Nuclei (AGN). We briefly review the history of the different techniques for finding AGN and compare and contrast the advantages and…

Astrophysics · Physics 2016-01-27 Richard Mushotzky

We compare the relative merits of AGN selection at X-ray and mid-infrared wavelengths using data from moderately deep fields observed by both Chandra and Spitzer. The X-ray-selected AGN sample and associated optical follow-up are drawn from…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Megan E. Eckart , Ian D. McGreer , Daniel Stern , Fiona A. Harrison , David J. Helfand

We study the host galaxy properties of active galactic nuclei (AGN) that have been detected in X-rays in the nearby Universe ($\rm z<0.2$). For that purpose, we use the catalogue provided by the ROSAT-2RXS in the 0.1-2.4\,keV energy band,…

Astrophysics of Galaxies · Physics 2022-02-02 L. Koutoulidis , G. Mountrichas , I. Georgantopoulos , E. Pouliasis , M. Plionis

Using a suite of X-ray, mid-IR and optical active galactic nuclei (AGN) luminosity indicators, we search for Compton-thick (CT) AGNs with intrinsic L_X>10^42erg/s at z~0.03-0.2, a region of parameter space which is currently poorly…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Andy Goulding , David Alexander , James Mullaney , Jonathan Gelbord , Ryan Hickox , Martin Ward , Mike Watson

The kinematic disturbances associated with major galaxy mergers are known to produce gas inflows, which in turn may trigger accretion onto the supermassive black holes (SMBH) of the participant galaxies. While this effect has been studied…

Astrophysics of Galaxies · Physics 2023-01-25 Robert W. Bickley , Sara L. Ellison , David R. Patton , Scott Wilkinson
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