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Using the spectra of a sample of $\sim$28,000 nearby obscured active galaxies from Data Release 7 of the Sloan Digital Sky Survey (SDSS), we probe the connection between AGN activity and star formation over a range of radial scales in the…

宇宙学与河外天体物理 · 物理学 2015-06-15 Stephanie M. LaMassa , Timothy M. Heckman , Andrew Ptak , C. Megan Urry

Active galactic nuclei (AGN) and galactic black hole binaries (GBHs) represent two classes of accreting black holes. They both contain an accretion disc emitting a thermal radiation, and a non-thermal X-ray emitting corona. GBHs exhibit…

星系天体物理 · 物理学 2015-05-27 M. A. Sobolewska , A. Siemiginowska , M. Gierlinski

Broad emission lines in active galactic nuclei (AGNs) mainly arise from gas photoionized by continuum radiation from an accretion disk around a central black hole. The shape of the broad-line profile, described by ${\cal D}_{_{\rm…

星系天体物理 · 物理学 2016-02-17 Pu Du , Jian-Min Wang , Chen Hu , Luis C. Ho , Yan-Rong Li , Jin-Ming Bai

From a Chandra sample of active galactic nuclei (AGNs) in nearby galaxies, we find that for low-luminosity AGNs (LLAGNs), either the intrinsic absorption column density, or the fraction of absorbed AGNs, positively scales with the Eddington…

高能天体物理现象 · 物理学 2018-06-27 Rui She , Luis C. Ho , Hua Feng , Can Cui

We discovered a significant anti-correlation between the mass of a supermassive black hole (SMBH), $M_{\rm BH}$, and the luminosity ratio of infrared to active galactic nuclei (AGN) Eddington luminosity, $L_{\rm IR}/L_{\rm Edd}$, over four…

天体物理学 · 物理学 2011-02-11 Nozomu Kawakatu , Masatoshi Imanishi , Tohru Nagao

We present the emission properties of a sample of 3,579 type 1 AGN, selected based on the detection of broad H-alpha emission. The sample covers the range of black hole mass 10^6<M_BH/M_Sun<10^9.5 and luminosity in Eddington units 10^-3 <…

宇宙学与河外天体物理 · 物理学 2012-03-23 Jonathan Stern , Ari Laor

The ratio in number between unobscured (type 1) and obscured (type 2) AGNs is often used to explore the structure of the torus in the unified scheme for active galactic nuclei (AGNs). Oh et al. (2015) investigated the type 1 AGN fraction on…

星系天体物理 · 物理学 2017-09-20 Honggeun Khim , Sukyoung K. Yi

X-ray variability is a well-established characteristic of active galactic nuclei (AGN), known to correlate inversely with both the supermassive black hole mass and luminosity, although the degree of each remains a topic of debate. The…

We report the discovery of the ``mm fundamental plane of black-hole accretion'', which is a tight correlation between the nuclear 1 mm luminosity ($L_{\rm \nu, mm}$), the intrinsic $2$ -- $10$~keV X-ray luminosity ($L_{\rm X,2-10}$) and the…

It has been argued for years that the accretion mode changes from bright active galactic nuclei (AGNs) to low-luminosity AGNs (LLAGNs) at a rough dividing point of bolometric Eddington ratio $\lambda \sim 10^{-2}$. In this work, we…

高能天体物理现象 · 物理学 2017-08-16 Shuang-Liang Li , Fu-Guo Xie

In this work we present a robust quantification of X-ray selected AGN in local ($z \leq 0.25$) dwarf galaxies ($M_\mathrm{*} \leq 3 \times 10^9 \mathrm{M_\odot}$). We define a parent sample of 4,331 dwarf galaxies found within the footprint…

星系天体物理 · 物理学 2020-01-29 Keir L Birchall , M G Watson , J Aird

Accreting supermassive black holes (SMBHs), also known as active galactic nuclei (AGN), are generally surrounded by large amounts of gas and dust. This surrounding material reprocesses the primary X-ray emission produced close to the SMBH…

The dependence of the long-term optical/UV variability on the spectral and the fundamental physical parameters for radio-quiet active galactic nuclei (AGNs) is investigated. The multi-epoch repeated photometric scanning data in the…

宇宙学与河外天体物理 · 物理学 2015-05-18 Y. L. Ai , W. Yuan , H. Y. Zhou , T. G. Wang , X. -B. Dong , J. G. Wang , H. L. Lu

In this study, we use the SWIFT/BAT AGN sample, which has received extensive multiwavelength follow-up analysis as a result of the BAT AGN Spectroscopic Survey (BASS), to develop a diagnostic for nuclear obscuration by examining the…

One of the remaining open issues in the context of the analysis of Active Galactic Nuclei (AGN) is the evidence that nuclear gravitational accretion is often accompanied by a concurrent starburst (SB) activity. What is, in this picture, the…

宇宙学与河外天体物理 · 物理学 2013-01-22 Anna Feltre

We present a discovery of the correlation between the X-ray spectral (photon) index and mass accretion rate observed in AGN NGC 4051. We analyzed spectral transition episodes observed in NGC 4051 using XMM/Newton, Suzaku and RXTE. We…

星系天体物理 · 物理学 2018-06-13 Elena Seifina , Alexandre Chekhtman , Lev Titarchuk

Revealing what fraction of galaxies harbor AGN is central in understanding black hole accretion history of the Universe. However, optical and soft X-ray surveys miss the most highly obscured AGNs. Infrared (IR), instead, is more robust…

星系天体物理 · 物理学 2019-03-20 Chia-Ying Chiang , Tomotsugu Goto , Tetsuya Hashimoto , Seong-Jin Kim , Hideo Matsuhara , Nagisa Oi

It is widely known that in active galactic nuclei (AGNs) and black hole X-ray binaries (BHXBs), there is a tight correlation among their radio luminosity ($L_R$), X-ray luminosity ($L_X$) and BH mass ($\mbh$), the so-called `fundamental…

星系天体物理 · 物理学 2018-07-04 Lei Qian , Xiao-Bo Dong , Fu-Guo Xie , Wenjuan Liu , Di Li

We create broadband SEDs of 761 type 1 AGN. The Scott et al. sample, created by a cross-correlation of the optical SDSS DR5 quasar catalogue and the 2XMMi catalogue of serendipitous X-ray sources, is further matched with the FIRST catalogue…

高能天体物理现象 · 物理学 2015-06-18 A. E. Scott , G. C. Stewart

We investigated the gas obscuration and host galaxy properties of active galactic nuclei (AGN) during the peak of cosmic accretion growth of supermassive black holes (SMBHs) at redshift 0.8-1.8 using X-ray detected AGN with mid-infrared and…