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Related papers: Fe II emission in active galactic nuclei

200 papers

Radio and gamma-ray emission from active galactic nuclei (AGN) are thought to share a common origin, related to the ejection phenomena in the vicinity of supermassive black holes. Thanks to its sensitivity, surveying capability, and broad…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-29 M. Giroletti , A. Reimer , L. Fuhrmann , V. Pavlidou , J. L. Richards

Here we investigate the kinematics of the part of the broad line region (BLR) in active galactic nuclei (AGNs) emitting H$\beta$ and H$\alpha$ emission lines. We explore the widths and asymmetries of the broad H$\beta$ and H$\alpha$…

Astrophysics of Galaxies · Physics 2022-08-24 Nemanja Rakić

We study the current discrepancy between the model-predicted and measured concentrations of Fe++ and Fe3+ in ionized nebulae. We calculate a set of photoionization models, updated with the atomic data relevant to the problem, and compare…

Astrophysics · Physics 2009-11-10 Monica Rodriguez , Robert H. Rubin

Broad (~10,000 km/s), double-peaked emission-line profiles of Balmer lines emitted by active galactic nuclei (AGN) are thought to originate in the outer parts of an accretion disk surrounding a nuclear supermassive black hole (SMBH), at…

We have calculated FeII emission line strengths for Active Galactic Nuclei Broad-Line Regions using precise radiative transfer and Iron Project atomic data. We improve the treatment of all previously considered excitation mechanisms for the…

Astrophysics · Physics 2009-10-30 T. A. A. Sigut , Anil K. Pradhan

We present a new sample of 116 double-peaked Balmer line Active Galactic Nuclei (AGN) selected from the Sloan Digital Sky Survey. Double-peaked emission lines are believed to originate in the accretion disks of AGN, a few hundred…

Astrophysics · Physics 2009-09-29 Iskra V. Strateva , Michael A. Strauss , Lei Hao , David J. Schlegel

We use Gaia Data Release 2 (DR2) to place 252 Herbig Ae/Be stars in the HR diagram and investigate their characteristics and properties. For all known Herbig Ae/Be stars with parallaxes in Gaia DR2, we collected their atmospheric parameters…

Solar and Stellar Astrophysics · Physics 2018-12-12 M. Vioque , R. D. Oudmaijer , D. Baines , I. Mendigutía , R. Pérez-Martínez

We present high resolution echelle spectroscopy of a sample of H II galaxies. In all galaxies we identify different H(alpha) emitting knots along the slit crossing the nucleus. All of these have been isolated and separately analyzed through…

Astrophysics · Physics 2009-10-31 Eduardo Telles , Casiana Munoz-Tunon , Guillermo Tenorio-Tagle

Knowledge of the broad-band active galactic nuclei (AGN) spectral energy distribution (SED) that ionizes the gas-rich broad emission line region is key to understanding the various radiative processes at play and their importance that…

Astrophysics of Galaxies · Physics 2025-05-30 Karla Garnica , Deborah Dultzin , Paola Marziani , Swayamtrupta Panda

Using cosmological simulations to make useful, scientifically relevant emission line predictions is a relatively new and rapidly evolving field. However, nebular emission lines have been particularly challenging to model because they are…

Astrophysics of Galaxies · Physics 2019-12-30 Kirk S. S. Barrow

We present spectra of a large sample of low-metallicity blue compact dwarf galaxies which exhibit broad components in their strong emission lines, mainly in Hbeta, [O III]4959, 5007 and Halpha. Twenty-three spectra have been obtained with…

Astrophysics · Physics 2018-05-30 Y. I. Izotov , T. X. Thuan , N. G. Guseva

The properties of the Galactic Ridge X-ray Emission (GRXE) observed in the 2-10 keV band place fundamental constraints on various types of X-ray sources in the Milky Way. Although the primarily discrete origin of the emission is now well…

High Energy Astrophysical Phenomena · Physics 2016-03-09 Xiao-jie Xu , Q. Daniel Wang , Xiang-Dong Li

This is the first paper in a series devoted to systematic study of the size and structure of the broad-line region (BLR) in active galactic nuclei (AGNs) using reverberation mapping (RM) data. We employ a recently developed Bayesian…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-07 Yan-Rong Li , Jian-Min Wang , Luis C. Ho , Pu Du , Jin-Ming Bai

We have compared the optical emission line ratios of type 2 quasars from Zakamska et al. with standard AGN photoionization model predictions, Seyfert 2s, HII galaxies, and narrow line FRII radio galaxies. Moderate to high ionization narrow…

The solar photospheric Fe abundance has been determined using realistic ab initio 3D, time-dependent, hydrodynamical model atmospheres. The study is based on the excellent agreement between the predicted and observed line profiles directly…

Astrophysics · Physics 2007-05-23 M. Asplund , AA. Nordlund , R. Trampedach , R. F. Stein

We present an analysis of deep mid- to far-infrared (MFIR) Spitzer photometric observations of the southern 2Jy sample of powerful radio sources (0.05 < z < 0.7), conducting a statistical investigation of the links between radio jet, AGN,…

Astrophysics · Physics 2011-02-11 D. Dicken , C. Tadhunter , D. Axon , R. Morganti , K. J. Inskip , J. Holt , R. Gonzalez Delgado , B. Groves

The high-ionization lines of the broad-line region (BLR) of thermal active galactic nuclei (AGNs) show blueshifts of a few hundred km/s to several thousand km/sec with respect to the low-ionization lines. This has long been thought to be…

Astrophysics of Galaxies · Physics 2016-02-03 C. Martin Gaskell , Rene W. Goosmann

The velocities of the [O III] 5007 and optical Fe II emission lines, measured relative to the systemic redshifts of 2265 QSOs by Hu et al. (2008), show the signature of a disklike BLR structure with polar outflows. Objects with large [O…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Todd A. Boroson

We test the recent claim by Hu et al. (2008) that FeII emission in Type 1 AGN shows a systematic redshift relative to the local source rest frame and broad-line Hbeta. We compile high s/n median composites using SDSS spectra from both the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 J. W. Sulentic , P. Marziani , S. Zamfir , Z. Meadows