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Related papers: Fe II emission in active galactic nuclei

200 papers

The issue of the difference between optical and UV properties of radio-quiet and radio-loud (relativistically "jetted") active galactic nuclei (AGN) is a long standing one, related to the fundamental question of why a minority of powerful…

Astrophysics of Galaxies · Physics 2021-12-07 Paola Marziani , Marco Berton , Swayamtrupta Panda , Edi Bon

Here we present observational evidence that the broad emission line region (BELR) of active galactic nuclei (AGN) generally has an outer boundary. This was already clear for sources with an obvious transition between the broad and narrow…

Astrophysics of Galaxies · Physics 2014-06-19 Hermine Landt , Martin J. Ward , Martin Elvis , Margarita Karovska

The 6.4 keV Fe Ka emission line is a ubiquitous feature in X-ray spectra of AGN, and its properties track the interaction between the variable primary X-ray continuum and the surrounding structure from which it arises. We clarify the nature…

We present a set of new theoretical Fe II templates for bright quasars covering a wavelength range of 1000-10000 \AA\, based on the recent atomic database available in the C23.00 version of the photoionization code CLOUDY. We compute a grid…

We present theoretical iron emission line strengths for physical conditions typical of Active Galactic Nuclei with Broad-Line Regions. The non-local thermodynamic equilibrium (NLTE) models include a new and extensive treatment of radiative…

Astrophysics · Physics 2009-11-10 T. A. A. Sigut , Anil K. Pradhan , Sultana N. Nahar

In an effort to better calibrate the supernova rate of starburst galaxies as determined from near-IR [Fe II] features, we report on a [Fe II] 1.644 microns line-imaging survey of a sample of 42 optically-selected SNRs in M33. A wide range…

Astrophysics · Physics 2009-11-07 T. Morel , R. Doyon , N. St-Louis

We review constraints on models of the broad line region that are imposed by observations of the emission lines in Active Galactic Nuclei. Comparison of high and low ionization lines in sources with FWHM Hbeta < 4000 km/s points toward low…

Astrophysics · Physics 2007-05-23 D. Dultzin-Hacyan , P. Marziani , J. W. Sulentic

Both the Fe II UV emission in the 2000- 3000 A region [Fe II (UV)] and resonance emission line complex of Mg II at 2800 A are prominent features in quasar spectra. The observed Fe II UV/ Mg II emission ratios have been proposed as means to…

Astrophysics · Physics 2009-11-10 E. Verner , F. Bruhweiler , D. Verner , S. Johansson , T. Gull

Broad emission lines are emitted in the surroundings of supermassive black holes in the centers of active galactic nuclei (AGN). This region is spatially not resolved. We intend to get information on the structure and geometry of this broad…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 W. Kollatschny , M. Zetzl

Double-peaked (DP) broad emission line profiles in active galactic nuclei (AGNs) are often interpreted as signatures of rotating disk-like structures in the broad-line region (BLR) and are commonly observed in low-luminosity AGNs using…

Astrophysics of Galaxies · Physics 2026-03-06 Kelly F. Heckler , Rogemar A. Riffel , Daniel Marsango , Tiago V. Ricci , Angela C. Krabbe , Oli L. Dors

We map the kinematics of the inner (200 pc) narrow-line region (NLR) of the Seyfert 2 galaxy NGC 1068 using the instrument NIFS and adaptative optics at the Gemini North Telescope. Channel maps and position-velocity diagrams are presented…

Astrophysics of Galaxies · Physics 2015-06-22 F. K. B. Barbosa , T. Storchi-Bergmann , P. McGregor , T. B. Vale

We investigate the excitation mechanisms of near-infrared [Fe ii] and H2 emission lines observed in Active Galactic Nuclei (AGNs). We built a photoionization model grid considering a two-component continuum, one accounts for the Big Bump…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Oli L. Dors , Rogemar A. Riffel , Monica V. Cardaci , Guillermo F. Hagele , Angela C. Krabbe , Enrique Perez-Montero , Irapuan Rodrigues

We investigate the emissivity properties of the main near-IR transitions of the Fe+ ion in the conditions prevailing in the inner regions of jets from young stars, based on a simplified 16-level atom model. We present new diagnostic…

Astrophysics · Physics 2009-11-10 N. Pesenti , C. Dougados , S. Cabrit , D. O'Brien , P. Garcia , J. Ferreira

We investigate the relationship between the linewidths of broad Mg II \lambda2800 and Hbeta in active galactic nuclei (AGNs) to refine them as tools to estimate black hole (BH) masses. We perform a detailed spectral analysis of a large…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Jian-Guo Wang , Xiao-Bo Dong , Ting-Gui Wang , Luis C. Ho , Weimin Yuan , Huiyuan Wang , Kai Zhang , Shaohua Zhang , Hongyan Zhou

Double-peaked emission lines are observed in a small percentage of active galactic nuclei (AGN). These lines allow the determination of properties of the line-emitting region, known as the broad-line region (BLR). We investigated the…

Astrophysics of Galaxies · Physics 2025-05-14 M. W. Ochmann , P. M. Weilbacher , M. A. Probst , W. Kollatschny , D. Chelouche , R. Chini , D. Grupe , M. Haas , S. Kaspi , S. Komossa

We performed 3D spectroscopic observations of Mrk 493 in order to investigate the Fe II emitting region and their possible connection with the Hydrogen emitting region. We found that there is a strong Fe II emission in an extensive region ~…

Astrophysics · Physics 2007-05-23 L. C. Popovic , A. Smirnova , D. Ilic , A. Moiseev , J. Kovacevic , V. Afanasiev

We study the low-contrast Fe II emission blends in the ultraviolet (1250--2200A) and optical (4000--6000A) spectra of the Seyfert 1 galaxy NGC 5548 and show that these features vary in flux and that these variations are correlated with…

Astrophysics · Physics 2009-11-10 M. Vestergaard , B. M. Peterson

We have modeled the full velocity-resolved reverberation response of the H$\beta$ and He II optical broad emission lines in NGC 3783 to constrain the geometry and kinematics of the low-ionization and high-ionization broad line region. The…

Astrophysics of Galaxies · Physics 2021-10-27 Misty C. Bentz , Peter R. Williams , Rachel Street , Christopher A. Onken , Monica Valluri , Tommaso Treu

A detailed analysis of the data from a high sampling rate, multi-month reverberation mapping campaign, undertaken primarily at MDM Observatory with supporting observations from telescopes around the world, reveals that the Hbeta emission…

In this study, a refined approach for multicomponent fitting of active galactic nuclei (AGN) spectra is presented utilizing the newly developed Python code $fantasy$ (fully automated python tool for AGN spectra analysis). AGN spectra are…

Astrophysics of Galaxies · Physics 2023-07-19 Dragana Ilic , Nemanja Rakic , Luka C. Popovic