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相关论文: The central parsecs of active galactic nuclei: cha…

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Aims: In this paper, we aim to constrain the properties of dust structures in the central first parsecs of Active Galactic Nuclei (AGN). Our goal is to study the required optical depth and composition of different dusty and ionised…

星系天体物理 · 物理学 2018-05-02 Lucas Grosset , Daniel Rouan , Damien Gratadour , Didier Pelat , Jan Orkisz , Frédéric Marin , René Goosmann

The obscuration observed in active galactic nuclei (AGN) is mainly caused by dust and gas distributed in a torus-like structure surrounding the supermassive black hole (SMBH). However, properties of the obscuring torus of the AGN in X-ray…

星系天体物理 · 物理学 2021-06-09 X. Zhao , S. Marchesi , M. Ajello , D. Cole , Z. Hu , R. Silver , N. Torres-Albà

Using Spitzer-IRS spectroscopy, we investigate the ubiquity of Active Galactic Nuclei (AGN) in a complete (~94%), volume-limited sample of the most bolometrically-luminous galaxies (L_IR > (0.3-20) x 10^10 L_sun) to D < 15 Mpc. Our analyses…

宇宙学与河外天体物理 · 物理学 2015-05-13 Andy Goulding , Dave Alexander

Active galactic nuclei (AGNs) are the compact, energetic central regions of galaxies, powered by supermassive black holes that accrete surrounding gas and dust. Their optical spectra can be identified by strong emission-line signatures…

星系天体物理 · 物理学 2026-01-09 Sruthi Suresh , Wei Jeat Hon , Rachel L Webster , Christian Wolf , Christopher A Onken

The Hubble Space Telescope WFPC2 is being used to obtain high-resolution images in the V and I bands for several thousand distant galaxies as part of the Medium Deep Survey (MDS). An important scientific aim of the MDS is to identify…

天体物理学 · 物理学 2009-10-28 Vicki L. Sarajedini , Richard F. Green , Richard E. Griffiths , Kavan U. Ratnatunga

While there are numerous criteria for photometrically identifying active galactic nuclei (AGNs), searches in the optical and UV tend to exclude galaxies that are highly dust obscured. This is problematic for constraining models of AGN…

星系天体物理 · 物理学 2018-07-17 Anson Lam , Edward L. Wright , Matthew A. Malkan

Type II quasars are luminous Active Galactic Nuclei whose centers are obscured by large amounts of gas and dust. In this paper we present 3-band HST images of nine type II quasars with redshifts 0.2 < z < 0.4 selected from the Sloan Digital…

We present high-resolution, broad- and narrow-band, pre-refurbishment images of the central region of M51 taken with the Planetary Camera of the Hubble Space Telescope. The V-band images show a rather chaotic distribution of dust lanes,…

天体物理学 · 物理学 2012-08-27 Carl J. Grillmair , S. M. Faber , Tod R. Lauer , J. J. Hester , C. R. Lynds , E. J. O'Neil, , P. A. Scowen

We use JWST/MIRI MRS spectroscopy of a sample of six local obscured type 1.9/2 active galactic nuclei (AGN) to compare their nuclear mid-IR absorption bands with the level of nuclear obscuration traced by X-rays. This study is the first to…

Nuclear starburst discs (NSDs) are star-forming discs that may be residing in the nuclear regions of active galaxies at intermediate redshifts. One dimensional (1D) analytical models developed by Thompson et al. (2005) show that these discs…

高能天体物理现象 · 物理学 2017-04-03 Raj Gohil , David R. Ballantyne

We determine the intrinsic shapes and orientations of 27,450 type I and II active galactic nucleus (AGN) galaxies in the spectroscopic sample of the SDSS DR7, by studying the distribution of projected axis ratios of AGN hosts. Our aim is to…

宇宙学与河外天体物理 · 物理学 2015-05-20 Claudia del P. Lagos , Nelson D. Padilla , Michael A. Strauss , Sofia A. Cora , Lei Hao

The material surrounding accreting supermassive black holes connects the active galactic nucleus (AGN) with its host galaxy and, besides being responsible for feeding the black hole, provides important information on the feedback that…

星系天体物理 · 物理学 2017-09-04 Cristina Ramos Almeida , Claudio Ricci

This review describes recent developments related to the unified model of active galactic nuclei (AGN). It focuses on new ideas about the origin and properties of the central obscurer (torus), and the connection with its surrounding. The…

星系天体物理 · 物理学 2015-09-23 Hagai Netzer

According to theory, the torus of active galactic nuclei (AGN) is sustained from a wind coming off the accretion disk, and for low efficient AGN, it has been proposed that such structure disappears. However, the exact conditions for its…

We use mid-infrared spectroscopy of unobscured active galactic nuclei (AGNs) to reveal their native dusty environments. We concentrate on Seyfert 1 galaxies, observing a sample of 31 with the Infrared Spectrograph aboard the Spitzer Space…

星系天体物理 · 物理学 2010-01-15 G. D. Thompson , N. A. Levenson , S. A. Uddin , M. M. Sirocky

The central region of NGC 1068 is one of the closest and most studied Active Galactic Nucleus. It is known to be of type 2, meaning that its accretion disk is obscured by a large amount of dust and gas. The main properties of the obscuring…

We present observations of the molecular gas in the nuclear environment of three prototypical low luminosity AGN (LLAGN), based on VLT/SINFONI AO-assisted integral-field spectroscopy of H2 1-0 S(1) emission at angular resolutions of ~0.17".…

宇宙学与河外天体物理 · 物理学 2015-06-12 F. Müller-Sánchez , M. A. Prieto , M. Mezcua , R. I. Davies , M. Malkan , M. Elitzur

Spectral energy distributions (SEDs) of the central few tens of parsec region of some of the nearest, most well studied, active galactic nuclei (AGN) are presented. These genuine AGN-core SEDs, mostly from Seyfert galaxies, are…

宇宙学与河外天体物理 · 物理学 2015-05-14 M. A. Prieto , J. Reunanen , K. R. W. Tristram , N. Neumayer , J. A. Fernandez-Ontiveros , M. Orienti , K. Meisenheimer

We present the results of Spitzer IRS low-resolution infrared 5-35 micron spectroscopy of nearby ultraluminous infrared galaxies (ULIRGs) at z < 0.15. We focus on the search for the signatures of buried active galactic nuclei (AGNs) in the…

NGC 4945 harbors one of the nearest active galactic nuclei (AGN), which allows reaching high spatial resolution with the current observational facilities. The Seyfert 2 nucleus is deeply obscured by an edge-on disk with $A_V\sim14$,…