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相关论文: Intermediate Inclinations of Type 2 Coronal-Line F…

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We analyse Compton-thick active galactic nuclei (CT AGNs), a heavily obscured subclass that challenges traditional X-ray diagnostics. Using 243 sources from the 70-Month \textit{SWIFT}/BAT catalogue (26 CT, 217 non-CT), we investigate their…

In this paper we study the nuclear obscuration of galaxies hosting LINERs based on their X-ray and optical emission. They show column densities (N_H) at soft energies (0.5-2 keV) mostly related to the diffuse emission around the AGN,…

星系天体物理 · 物理学 2014-11-20 O. Gonzalez-Martin , J. Masegosa , I. Marquez , M. Guainazzi

Some galaxies show little to no sign of active galactic nucleus (AGN) activity, yet exhibit strong coronal emission lines (CLs) relative to common narrow emission lines. Many of these CLs have ionization potentials of $\geq 100$ eV, thus…

高能天体物理现象 · 物理学 2024-08-27 Jason T. Hinkle , Benjamin J. Shappee , Thomas W. -S. Holoien

The fundamental nature and extent of the coronal line region (CLR), which may serve as a vital tracer for Active Galactic Nucleus (AGN) activity, remain unresolved. Previous studies suggest that the CLR is produced by AGN-driven outflows…

We describe improved modelling of the emission by dust in a toroidal--like structure heated by a central illuminating source within Active Galactic Nuclei (AGN). We chose a simple but realistic torus geometry, a flared disc, and a dust…

天体物理学 · 物理学 2009-11-13 J. Fritz , A. Franceschini , E. Hatziminaoglou

The ionizing fluxes from quasars and other active galactic nuclei (AGN) are critical for interpreting the emission-line spectra of AGN and for photoionization and heating of the intergalactic medium. Using ultraviolet spectra from the…

宇宙学与河外天体物理 · 物理学 2015-06-04 J. Michael Shull , Matthew Stevans , Charles W. Danforth

We have obtained Keck NIR spectroscopy of a sample of nine M$_\star$ $<$ 10$^{10}$ M$_\odot$ dwarf galaxies to confirm AGN activity and the presence of galaxy-wide, AGN-driven outflows through coronal line (CL) emission. We find strong CL…

星系天体物理 · 物理学 2021-04-28 Thomas Bohn , Gabriela Canalizo , Sylvain Veilleux , Weizhe Liu

Coronal lines (CLs), which arise from collisionally excited forbidden transitions from highly ionized species, are a powerful diagnostic tool in uncovering active galactic nuclei (AGNs) and constraining their properties. However, recent…

星系天体物理 · 物理学 2025-02-24 William Matzko , Shobita Satyapal , Michael Reefe , Jeffrey McKaig , Remington O. Sexton , Sara Doan

The luminous electromagnetic emission from distant active galactic nuclei (AGNs) including quasars is believed to be powered by accretion onto super-massive black holes (SMBHs). In the standard unification model for AGNs a dusty torus…

天体物理学 · 物理学 2009-11-10 Shuang Nan Zhang

We provide a comprehensive census of the near-Infrared (NIR, 0.8-2.4 $\mu$m) spectroscopic properties of 102 nearby (z < 0.075) active galactic nuclei (AGN), selected in the hard X-ray band (14-195 keV) from the Swift-Burst Alert Telescope…

We present observational evidence supporting the presence of a stratified accretion disk wind in active galactic nuclei (AGN), based on multi-wavelength spectroscopic analysis of broad and narrow emission lines. The diversity in emission…

星系天体物理 · 物理学 2025-12-30 P. Marziani , E. Bon , S. Panda , N. Bon , A. Del Olmo , A. Deconto-Machado , K. Garnica , D. Dultzin

From detailed spectral analysis of a large sample of low-redshift active galactic nuclei (AGNs) selected from the Sloan Digital Sky Survey, we demonstrate---statistically for the first time---that narrow optical Fe II emission lines, both…

星系天体物理 · 物理学 2010-09-14 Xiao-Bo Dong , Luis C. Ho , Jian-Guo Wang , Ting-Gui Wang , Huiyuan Wang , Xiaohui Fan , Hongyan Zhou

The rare case of changing-look (CL) AGNs, with the appearance or disappearance of broad Balmer emission lines within a few years, challenges our understanding of the AGN unified model. We present a sample of 21 new CL AGNs at $0.08<z<0.58$,…

We present a comprehensive comparative high resolution mid-IR spectroscopic and X-ray imaging investigation of LINERs using archival observations from the ISO-SWS and the Chandra Advanced CCD Imaging Spectrometer. Although the sample is…

天体物理学 · 物理学 2009-11-10 S. Satyapal , R. M. Sambruna , R. P. Dudik

We report the \Suzaku/XIS and HXD and \Chandra/ACIS-I results on the X-ray spectra of the Phoenix cluster at the redshift $z=0.596$. The spectrum of the intracluster medium (ICM) is well-reproduced with the emissions from a low temperature…

宇宙学与河外天体物理 · 物理学 2015-06-17 Shutaro Ueda , Kiyoshi Hayashida , Naohisa Anabuki , Hiroshi Nakajima , Katsuji Koyama , Hiroshi Tsunemi

We report the new finding that type 1 Seyfert nuclei (S1s) have excess [FeVII]6087 emission with respect to type 2s (S2s). The S1s exhibit broad emission lines which are attributed to ionized gas within 1 pc of the black hole, whereas the…

天体物理学 · 物理学 2009-10-30 Takashi Murayama , Yoshiaki Taniguchi

We investigated by means of MUSE/VLT observations the true size of the coronal line region (CLR) in a local sample of nine active galactic nuclei known for displaying prominent coronal emission. Our analysis show that the CLR is extended…

星系天体物理 · 物理学 2025-03-14 A. Rodríguez-Ardila , M. A. Fonseca-Faria , L. G. Dahmer-Hahn , A. Prieto , R. Riffel , R. A. Riffel

We conduct the first systematic survey of a comprehensive set of the twenty optical coronal lines in the spectra of nearly 1 million galaxies observed by the Sloan Digital Sky Survey (SDSS) Data Release 8 catalog. This includes often…

星系天体物理 · 物理学 2022-09-16 Michael Reefe , Shobita Satyapal , Remington O. Sexton , Sara M. Doan , Nathan J. Secrest , Jenna M. Cann

Stern et al.(2012) presented a study of WISE selection of AGN in the 2 deg^2 COSMOS field, finding that a simple criterion W1-W2>=0.8 provides a highly reliable and complete AGN sample for W2<15.05, where the W1 and W2 passbands are…

We estimate the abundance of Compton-thick (CT) active galactic nuclei (AGN) based on our joint model of X-ray and infrared backgrounds. At L_{rest 2-10 keV} > 10^42 erg/s, the CT AGN density predicted by our model is a few 10^-4 Mpc^-3…

宇宙学与河外天体物理 · 物理学 2015-06-17 Yong Shi , George Helou , Lee Armus