中文
相关论文

相关论文: Exploring the Partially-obscured BLR and Partially…

200 篇论文

One primary difficulty in understanding the nature of the putative accretion disk in the central engine of AGNs is that some of its key intrinsic spectral signatures are buried under the emissions from the surrounding regions, i.e. the…

天体物理学 · 物理学 2007-05-23 Makoto Kishimoto , Robert Antonucci , Omer Blaes

The unprecedented sensitivity of the James Webb Space Telescope (JWST) has uncovered a surprisingly abundant population of mildly obscured, low-luminosity active galactic nuclei (AGNs) in the epoch of reionization (EoR). However, the link…

There is clear observational evidence that some narrow line (type 2) AGN have a hidden broad line region (BLR), and are thus intrinsically broad line (type 1) AGN. Does this AGN unification applies for all type 2 AGN? Indirect arguments…

天体物理学 · 物理学 2009-11-07 Ari Laor

We use the Balmer decrements of the broad-line regions (BLRs) and narrow-line regions (NLRs) of active galactic nuclei (AGNs) as reddening indicators to investigate the location of the dust for four samples of AGNs with reliable estimates…

星系天体物理 · 物理学 2016-09-07 Clio Z. P. Heard , C. Martin Gaskell

We have compiled a sample of 21 low redshift (z < 0.3), luminous active galactic nuclei (AGN) with large Balmer decrements (Halpha/Hbeta > 7) using the galaxy and QSO catalogs of the Sloan Digital Sky Survey Early Data Release. Using this…

天体物理学 · 物理学 2009-09-24 Xiao-Bo Dong , Hong-Yan Zhou , Ting-Gui Wang , Jun-Xian Wang , Cheng Li , You-Yuan Zhou

Early studies of nearby Seyfert galaxies have led to the picture that the Narrow Line Region (NLR) is a cone-shaped region of gas ionized by radiation from a nuclear source collimated by a dusty torus, where the gas is in outflow. In this…

星系天体物理 · 物理学 2015-06-23 Thaisa Storchi-Bergmann

A crucial difficulty in understanding the nature of the putative accretion disk in AGNs is that some of its key intrinsic spectral signatures cannot be observed directly. The strong emissions from the broad-line region (BLR) and the…

Extended narrow-line regions (NLRs) around active galactic nuclei (AGN) are shaped by the distribution of gas in the host galaxy and by the geometry of the circumnuclear obscuration, and thus they can be used to test the AGN unification…

Most of the optically classified low ionisation narrow emission-line regions (LINERs) nuclei host an active galactic nuclei (AGN). However, how they fit into the unified model (UM) of AGN is still an open question. The aims of this work are…

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 study the physical and kinematic properties of the narrow line region (NLR) of the nearest obscured quasar MRK 477 (z=0.037), using optical and near-infrared spectroscopy. We explore a diversity of aspects that provide a more complete…

星系天体物理 · 物理学 2015-09-30 M. Villar Martin , E. Bellocchi , J. Stern , C. Ramos Almeida , C. Tadhunter , R. Gonzalez Delgado

I review progress made in understanding the nature of the broad-line region (BLR) of active galactic nuclei (AGNs) and the role BLRs play in the AGN phenomenon. The high equivalent widths of the lines imply a high BLR covering factor, and…

宇宙学与河外天体物理 · 物理学 2015-05-13 C. Martin Gaskell

We compare recent HST observations of Seyfert and quasar NLRs and find that type-2 AGNs follow a relation consistent with that expected for a distribution of gas ionized by a central source R(NLR,2) \propto L^{0.32 +/- 0.05}, while type-1…

天体物理学 · 物理学 2009-11-10 Nicola Bennert , Heino Falcke , Yuri Shchekinov , Andrew S. Wilson

Using the X-ray-selected active galactic nuclei (AGN) from the XMM-XXL north survey and the SDSS Baryon Oscillation Spectroscopic Survey (BOSS) spectroscopic follow-up of them, we compare the properties of X-ray unobscured and obscured…

The presence of an active galactic nucleus (AGN) can strongly affect its host. Due to the copious radiative power of the nucleus, the effects of radiative feedback can be detected over the entire host galaxy and sometimes well into the…

星系天体物理 · 物理学 2018-05-02 Ross Dempsey , Nadia Zakamska

We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGN) with clumpy torus models. We compiled high spatial resolution ($\sim 0.3$--$0.7$ arcsec) mid-IR $N$-band spectroscopy,…

We have newly identified a substantial number of type 1 active galactic nuclei (AGN) featuring weak broad-line regions (BLRs) at z < 0.2 from detailed analysis of galaxy spectra in the Sloan Digital Sky Survey Data Release 7. These objects…

星系天体物理 · 物理学 2015-07-15 Kyuseok Oh , Sukyoung K. Yi , Kevin Schawinski , Michael Koss , Benny Trakhtenbrot

Strong both broad and narrow emission lines from central broad emission line regions (BLRs) and narrow emission line regions (NLRs) are fundamental spectroscopic characteristics of broad line Active Galactic Nuclei (BLAGNs). Lack of central…

星系天体物理 · 物理学 2025-06-24 Zhang XueGuang

We consider in detail the spectral energy distribution (SED) and multi-wavelength variability of NGC5548. Comparison with the SEDs of other AGNs implies that the internal reddening of NGC5548 is E(B-V) = 0.17 mag. The extinction curve is…

天体物理学 · 物理学 2007-11-08 C. Martin Gaskell , Elizabeth S. Klimek , Ludmila S. Nazarova

The radio-loud AGN unification model associates powerful radio galaxies with radio-loud quasars and blazars. In analogy with the radio-quiet scheme, the nuclear regions of objects showing only narrow emission lines in their optical spectrum…

天体物理学 · 物理学 2017-08-23 Marco Chiaberge
‹ 上一页 1 2 3 10 下一页 ›