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

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We here report a spectroscopic identification of two new changing-look AGNs (CL-AGNs): SDSS\,J104705.16+544405.8 and SDSS\,J120447.91+170256.8 both with a "turn-off" type transition from type 1 to type 1.8/1.9. The identification is arrived…

星系天体物理 · 物理学 2020-01-08 J. Wang , D. W. Xu , Y. Wang , J. B. Zhang , J. Zheng , J. Y. Wei

We present an analysis of STIS/HST optical spectra of a sample of ten Seyfert galaxies aimed at studying the structure and physical properties of the coronal-line region (CLR). The high-spatial resolution provided by STIS allowed us to…

星系天体物理 · 物理学 2015-05-18 Ximena Mazzalay , Alberto Rodríguez-Ardila , S. Komossa

Polar dust has been found to play an important role in the mid-infrared emission of nearby Seyfert nuclei. If and how often polar dust exists among the quasar population is unknown due to the lack of spatially-resolved observations. In this…

星系天体物理 · 物理学 2022-12-02 Jianwei Lyu , George H. Rieke

Coronal lines are forbidden emission lines with a ionisation potential $\chi\gtrsim100\,{\rm eV}$. They are linked to energetic phenomena triggered by AGNs in the circumnuclear medium. We present the first high-angular-resolution…

星系天体物理 · 物理学 2025-04-14 S. Comerón , A. Prieto , P. Dabhade

We model the spectropolarimetric signature resulting from the radiative coupling between the innermost parts of active galactic nuclei (AGNs). We use a new public version of STOKES, a Monte Carlo radiative transfer code presented in the…

高能天体物理现象 · 物理学 2015-06-11 F. Marin , R. W. Goosmann , C. M. Gaskell , D. Porquet , M. Dovciak

Aims. High angular resolution N-band imaging is used to discern the torus of active galactic nuclei (AGN) from its environment in order to allow a comparison of its mid-infrared properties to the expectations of the unified scenario for…

星系天体物理 · 物理学 2009-11-13 Hannes Horst , Wolfgang J. Duschl , Poshak Gandhi , Alain Smette

We analyze a sample of 30,000 nearby obscured AGNs with optical spectra from SDSS and mid-IR photometry from WISE. Our aim is to investigate the AGN host galaxy properties with mid-IR luminosities as AGN activity indicator, and to compare…

宇宙学与河外天体物理 · 物理学 2015-06-15 Li Shao , Guinevere Kauffmann , Cheng Li , Jing Wang , Timothy M. Heckman

Despite the importance of AGN in galaxy evolution, accurate AGN identification is often challenging, as common AGN diagnostics can be confused by contributions from star formation and other effects (e.g., Baldwin-Phillips-Terlevich…

Mid-infrared photometry provides a robust technique for identifying active galaxies. While the ultraviolet to mid-infrared continuum of normal galaxies is dominated by the composite stellar black body curve and peaks at approximately 1.6…

The discovery of changing-look active galactic nuclei (CLAGNs) with the significant change of optical broad emission lines (optical CLAGNs) and/or strong variation of line-of-sight column densities (X-ray CLAGNs) challenges the…

高能天体物理现象 · 物理学 2022-03-30 Lyu Bing , Wu Qingwen , Yan Zhen , Yu Wenfei , Liu Hao

We present a detailed comparison between the 2-10 keV hard X-ray and infrared (IR) luminosity function (LF) of active galactic nuclei (AGN). The composite X-ray to IR spectral energy distributions (SEDs) of AGN used for connecting the hard…

星系天体物理 · 物理学 2014-08-29 Yunkun Han , Benzhong Dai , Bo Wang , Fenghui Zhang , Zhanwen Han

Reionisation-era galaxies often display intense nebular emission lines, both in rest-frame optical ([OIII]+H$\beta$) and ultraviolet (UV; CIII], CIV). How such strong nebular emission is powered remains unclear, with both active galactic…

The spectral energy distributions and infrared (IR) spectra of a sample of obscured AGNs selected in the mid-IR are modeled with recent clumpy torus models to investigate the nature of the sources, the properties of the obscuring matter,…

天体物理学 · 物理学 2010-03-19 M. Polletta , D. Weedman , S. Hoenig , C. J. Lonsdale , H. E. Smith , J. Houck

We analyze X-ray spectra of heavily obscured (N_H > 10^{24} cm^{-2}) active galaxies obtained with Chandra, concentrating on the iron K alpha fluorescence line. We measure very large equivalent widths in most cases, up to 5 keV in the most…

天体物理学 · 物理学 2009-11-07 N. A. Levenson , J. H. Krolik , P. T. Zycki , T. M. Heckman , K. A. Weaver , H. Awaki , Y. Terashima

We compile a sample of 89 Seyfert galaxies with both [OIV] 25.89 um line luminosities observed by Spitzer IRS and X-ray spectra observed by XMM EPIC. Using [OIV] emission as proxy of AGN intrinsic luminosity, we find that although type 2…

高能天体物理现象 · 物理学 2013-01-16 Teng Liu , Jun-Xian Wang

The orientation-based unification model of active galactic nuclei (AGNs) posits that the principle difference between obscured (Type 2) and unobscured (Type 1) AGNs is the line-of-sight into the central engine. If this model is correct than…

宇宙学与河外天体物理 · 物理学 2016-09-21 D. R. Ballantyne

We study "buried" active galactic nuclei (AGNs) almost fully covered by circumnuclear material in ultra-/luminous infrared galaxies (U/LIRGs), which show weak ionized lines from narrow line regions. Employing an indicator of [O IV] 25.89-um…

We present the first intensive study of the variability of the near-infrared coronal lines in an active galactic nucleus (AGN). We use data from a one-year long spectroscopic monitoring campaign with roughly weekly cadence on NGC 5548 to…

星系天体物理 · 物理学 2022-09-14 Daniel Kynoch , Hermine Landt , Maryam Dehghanian , Martin J. Ward , Gary J. Ferland

Context: We investigate mid-infrared and X-ray properties of the dusty torus in unification scenarios for active galactic nuclei. Aims: We use the relation between mid IR and hard X-ray luminosities to constrain AGN unification scenarios.…

天体物理学 · 物理学 2009-11-11 Hannes Horst , Alain Smette , Poshak Gandhi , Wolfgang J. Duschl