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Related papers: Interpreting the Ionization Sequence in AGN Emissi…

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Passive red galaxies frequently contain warm ionized gas and have spectra similar to low-ionization nuclear emission-line regions (LINERs). Here we investigate the nature of the ionizing sources powering this emission, by comparing nuclear…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Renbin Yan , Michael R. Blanton

We have studied the relationship between the high- and low-ionization [O IV] lambda 25.89 micron, [Ne III] lambda 15.56 micron and [Ne II] lambda 12.81 micron emission lines with the aim of constraining the active galactic nuclei (AGN) and…

Increasing evidence shows that AGN with radio detections have more perturbed ionized gas kinematics and higher outflow detection rates, suggesting a link between radio emission and these processes. In galaxies with weak or ambiguous AGN…

Astrophysics of Galaxies · Physics 2026-03-04 Marco Albán , Dominika Wylezalek , Pranav Kukreti , Rogemar A. Riffel , Rogerio Riffel

A cross-correlation of the SDSS DR7 with the FIRST radio survey makes it possible to conduct a joined multiwavelength statistical study of radio-optical galaxy properties on a very large number of sources. Our goal is to improve the study…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 M. Vitale , J. Zuther , M. Garcia-Marin , A. Eckart , M. Bremer , M. Valencia-S. , A. Zensus

We present a new scheme for modeling the broad line region in active galactic nuclei (AGNs). It involves photoionization calculations of a large number of clouds, in several pre-determined geometries, and a comparison of the calculated line…

Astrophysics · Physics 2009-10-31 Shai Kaspi , Hagai Netzer

Active Galactic Nuclei (AGN) unification, which implies a large number of obscured AGN, can explain the optical, infrared and X-ray content of deep multiwavelength surveys. Here, we show that the same model also successfully explains the…

Astrophysics · Physics 2007-05-23 Ezequiel Treister , C. M. Urry

We study the incidence of nuclear obscuration on a complete sample of 1310 AGN selected on the basis of their rest-frame 2-10 keV X-ray flux from the XMM-COSMOS survey, in the redshift range 0.3<z<3.5. We classify the AGN as obscured or…

Since the discovery of active galactic nuclei (AGN) and their subclasses, a unification scheme of AGN has been long sought. Orientation-based unified models predict that some of the diversity within AGN subclasses can be explained by the…

Astrophysics of Galaxies · Physics 2020-01-08 Suk Yee Yong , Rachel L. Webster , Anthea L. King , Nicholas F. Bate , Kathleen Labrie , Matthew J. O'Dowd

In this work, we spectroscopically select narrow-line AGNs (NLAGNs) among the ~300 publicly available medium-resolution spectra of the Cosmic Evolution Early Release Science Survey (CEERS). Using both traditional and newly identified…

(Abridge): We present a spectroscopic study of the stellar populations of Low Luminosity AGN (LLAGN). Our main goal is to determine whether the stars who live in the innermost (100 pc-scale) regions of these galaxies are in some way related…

We show that the recently observed suppression of the gap between the broad line region (BLR) and the narrow line region (NLR) in some AGN can be fully explained by an increase of the gas density in the emitting region. Our model predicts…

Astrophysics of Galaxies · Physics 2016-11-17 T. P. Adhikari , A. Różańska , B. Czerny , K. Hryniewicz , G. J. Ferland

Active Galactic Nuclei (AGN) are highly energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, which present unique observational signatures covering the full electromagnetic spectrum (and more) over…

High Energy Astrophysical Phenomena · Physics 2023-04-05 Stefano Bianchi , Vincenzo Mainieri , Paolo Padovani

After exploring the infrared softness diagram to characterize the hardness of the incident ionizing radiation in star-forming regions, we exploit the availability of high-excitation lines in the same spectral regime to explore its use for…

Astrophysics of Galaxies · Physics 2025-04-30 E. Pérez-Montero , J. A. Fernández-Ontiveros , B. Pérez-Díaz , J. M. Vílchez , R. Amorín

The unification of active galactic nuclei (AGN) is a model that has been difficult to test due to the lack of knowledge on the intrinsic luminosities of the objects. We present a test were we probe the model by statistical investigation of…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-05 Beatriz Villarroel , Andreas Korn , Yoshiki Matsuoka

Low-luminosity active galactic nuclei (LLAGNs) represent the bulk of the AGN population in the present-day universe and they trace the low-level accreting supermassive black holes. In order to probe the accretion and jet physical properties…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-21 Rodrigo Nemmen , Thaisa Storchi-Bergmann , Michael Eracleous

We present an analysis of the mid-infrared emission lines for a sample of 12 low metallicity Blue Compact Dwarf (BCD) galaxies based on high resolution observations obtained with Infrared Spectrograph on board the {\rm Spitzer} Space…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Lei Hao , Yanling Wu , V. Charmandaris , H. W. W. Spoon , J. Bernard-Salas , D. Devost , V. Lebouteiller , J. R. Houck

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,…

Astrophysics of Galaxies · Physics 2014-11-20 O. Gonzalez-Martin , J. Masegosa , I. Marquez , M. Guainazzi

We present a simplified model of Active Galactic Nucleus (AGN) continuum emission designed for photoionization modeling. The new model {\sc oxaf} reproduces the diversity of spectral shapes that arise in physically-based models. We identify…

Astrophysics of Galaxies · Physics 2016-12-28 Adam D. Thomas , Brent A. Groves , Ralph S. Sutherland , Michael A. Dopita , Chichuan Jin , Lisa J. Kewley

We present the first spatially resolved investigation of near-infrared coronal lines in dwarf galaxies hosting active galactic nuclei (AGN), using JWST/NIRSpec integral field spectroscopy. Coronal lines (CLs), which are forbidden…

Metallicity ($Z$) estimates based on ultraviolet (UV) emission lines from the narrow-line regions (NLRs) of active galactic nuclei (AGNs) have been found to differ from those derived from optical lines. However, the origin of this…