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相关论文: Detecting Obscured AGN in the Distant Universe wit…

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We present here a new spectral energy distribution (SED) fitting approach that we adopt to select radio-excess sources amongst distant star-forming galaxies in the GOODS-Herschel (North) field and to reveal the presence of hidden, highly…

Highly obscured active galactic nuclei (AGN) are common in nearby galaxies, but are difficult to observe beyond the local Universe, where they are expected to significantly contribute to the black hole accretion rate density. Furthermore,…

Statistical studies of X-ray selected Active Galactic Nuclei (AGN) indicate that the fraction of obscured AGN increases with increasing redshift, and the results suggest that a significant part of the accretion growth occurs behind…

A complete census of Active Galactic Nuclei (AGN) is a prerequisite for understanding the growth of supermassive black holes across cosmic time. A significant challenge toward this goal is the whereabouts of heavily obscured AGN that remain…

To optimally identify candidates of the Compton-thick (CT) active galactic nuclei (AGN) that contribute to the unresolved X-ray background in infrared surveys, a tracer of column density is desirable in addition to an AGN indicator. In a…

宇宙学与河外天体物理 · 物理学 2011-10-19 K. M. Dasyra , I. Georgantopoulos , A. Pope , M. Rovilos

Mateos et al. (2012) presented a highly reliable and efficient mid-infrared (MIR) colour-based selection technique for luminous active galactic nuclei (AGN) using the Wide-field Infrared Survey Explorer (WISE) survey. Here we evaluate the…

宇宙学与河外天体物理 · 物理学 2015-06-16 S. Mateos , A. Alonso-Herrero , F. J. Carrera , A. Blain , P. Severgnini , A. Caccianiga , A. Ruiz

The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured Active Galactic Nuclei…

宇宙学与河外天体物理 · 物理学 2015-05-14 M. Brusa , F. Fiore , P. Santini , A. Grazian , A. Comastri , G. Zamorani , G. Hasinger , A. Merloni , F. Civano , A. Fontana , V. Mainieri

Obscured AGN are fundamental to understand the history of Super Massive Black Hole growth and their influence on galaxy formation. However, the Compton-thick AGN (NH>1e24 cm^-2) population is basically unconstrained, with less than few…

宇宙学与河外天体物理 · 物理学 2015-05-20 P. Severgnini , A. Caccianiga , R. Della Ceca , V. Braito , C. Vignali , V. La Parola , A. Moretti

The Compton-thick Active Galactic Nuclei (AGN) arguably constitute the most elusive class of sources as they are absorbed by large column densities above logN_H(cm^-2)=24. These extreme absorptions hamper the detection of the central source…

星系天体物理 · 物理学 2025-03-12 I. Georgantopoulos , E. Pouliasis , A. Ruiz , A. Akylas

Heavily obscured, Compton Thick (CT, NH>10^24 cm^-2) AGN may represent an important phase in AGN/galaxy co-evolution and are expected to provide a significant contribution to the cosmic X-ray background (CXB). Through direct X-ray spectra…

In order to answer some of the major open questions in the fields of supermassive black hole (SMBH) and galaxy evolution, a complete census of SMBH growth, i.e., active galactic nuclei (AGN), is required. Thanks to deep all-sky surveys,…

We investigate infrared colours and spectral energy distributions (SEDs) of 338 X-ray selected AGN from Swift-BAT 105-month survey catalogue that have AKARI detection, in order to find a new selection criteria for Compton-thick AGN. By…

星系天体物理 · 物理学 2020-05-20 Ece Kilerci-Eser , Tomotsugu Goto , Tolga Guver , Asli Tuncer , Oguz Han Atas

Hard X-ray selection is the most efficient way to discriminate between accretion-powered sources, such as AGN, from sources dominated by starlight. Hard X-rays are also less affected than other bands by obscuration. We have then carried out…

天体物理学 · 物理学 2009-10-31 F. Fiore , F. La Franca , P. Giommi , M. Elvis , G. Matt , A. Comastri , S. Molendi , I. Gioia

We present a detailed spectral analysis of the brightest Active Galactic Nuclei (AGN) identified in the 7Ms Chandra Deep Field South (CDF-S) survey over a time span of 16 years. Using a model of an intrinsically absorbed power-law plus…

In this work, we study the AGN radio detection effectiveness in the major deep extragalactic surveys, considering different AGN obscuration levels, redshift, and AGN bolometric luminosities. We particularly focus on comparing their radio…

Deep Chandra X-ray exposures provide an efficient route for locating optically faint active galactic nuclei (AGN) at high redshifts. We use deep multicolor optical data to search for z>5 AGN in the 2 Ms X-ray exposure of the Chandra Deep…

We use observations from the 9 square degree multiwavelength survey in Bootes to identify hundreds of obscured active galactic nuclei (AGN) with high redshifts (z > 0.7), luminosities (L_bol > 10^45 ergs/s), and moderate obscuring columns…

This work discusses the broadband X-ray spectral analysis of 11 candidate heavily-obscured active galactic nuclei (AGN) selected based on their infrared and X-ray properties by a recently published machine learning algorithm. This paper is…

Spitzer/IRAC color selection is a promising technique to identify hot accreting nuclei, that is to say AGN, in galaxies. We demonstrate this using a small sample of SAURON galaxies, and explore this further. The goal of this study is to…

星系天体物理 · 物理学 2020-08-19 Tuba İkiz , Reynier F. Peletier , Peter D. Barthel , Cahit Yeşilyaprak

Heavily obscured Active Galactic Nuclei (AGN), especially Compton-thick sources with line-of-sight column density ($N_{\rm H,los}$) $>$ 10$^{24}$ cm$^{-2}$, are critical to understanding supermassive black hole (SMBH) growth and the origin…