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Related papers: Radio Bimodality: Spin, Accretion Mode, or Both?

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We investigate the conjecture by Sikora, Stawarz & Lasota (2007) that the observed AGN--radio-loudness bimodality can be explained by the morphology-related bimodality of black-hole spin distribution in the centers of galaxies: central…

Astrophysics · Physics 2009-11-13 Marta Volonteri , Marek Sikora , Jean-Pierre Lasota

Active galactic nuclei (AGNs) form two distinct sequences on the radio-loudness -- Eddington-ratio plane. The `upper' sequence contains radio selected AGNs, the `lower' sequence is composed mainly of optically selected AGNs. The sequences…

Astrophysics · Physics 2009-06-23 M. Sikora , L. Stawarz , J. -P. Lasota

We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. We find that AGNs form two distinct and well separated sequences on the radio-loudness -…

Astrophysics · Physics 2007-07-17 L. Stawarz , M. Sikora , J. -P. Lasota

We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. Our studies cover about seven orders of magnitude in accretion luminosity and the full range…

Astrophysics · Physics 2008-11-26 M. Sikora , L. Stawarz , J. -P. Lasota

The theoretical model suggests that relativistic jets of AGN rely on the black hole spin and/or accretion. We study the relationship between jet, accretion, and spin using supermassive black hole samples with reliable spin of black holes.…

High Energy Astrophysical Phenomena · Physics 2024-10-11 Yongyun Chen , Qiusheng Gu , Jianghe Yang , Junhui Fan , Xiaoling Yu , Dingrong Xiong , Nan Ding , Xiaotong Guo

A toy model for jet powers and radio loudness of active galactic nuclei (AGNs) is proposed based on the coexistence of the Blandford-Znajek (BZ) and magnetic coupling (MC) processes (CEBZMC) in black hole (BH) accretion disc. It turns out…

Astrophysics · Physics 2016-08-30 Yong-Chun Ye , Ding-Xiong Wang

We use a combination of a cosmological N-body simulation of the concordance Lambda cold dark matter (LCDM) paradigm and a semi-analytic model of galaxy formation to investigate the spin development of central supermassive black holes (BHs)…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Claudia del P. Lagos , Nelson D. Padilla , Sofia A. Cora

We compare accretion and black hole spin as potential energy sources for outbursts from AGN in brightest cluster galaxies (BCGs). Based on our adopted spin model, we find that the distribution of AGN power estimated from X-ray cavities is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 B. R. McNamara , M. Rohanizadegan , P. E. J. Nulsen

Radio mode feedback, in which most of the energy of an active galactic nucleus (AGN) is released in a kinetic form via radio-emitting jets, is thought to play an important role in the maintenance of massive galaxies in the present-day…

Astrophysics of Galaxies · Physics 2015-06-22 W. Ishibashi , M. W. Auger , D. Zhang , A. C. Fabian

We investigate whether models based on the assumption that jets in quasars are powered by rotating black holes can explain the observed radio dichotomy of quasars. We show that in terms of the ``spin paradigm'' models, radio-loud quasars…

Astrophysics · Physics 2009-10-30 R. Moderski , M. Sikora , J. -P. Lasota

Under the assumption that jets in active galactic nuclei are powered by accretion and the spin of the central supermassive black hole, we are able to reproduce the radio luminosity functions of high- and low-excitation galaxies.…

High Energy Astrophysical Phenomena · Physics 2012-02-01 Alejo Martinez-Sansigre , Steve Rawlings

We use recent progress in simulating the production of magnetohydrodynamic jets around black holes to derive the cosmic spin history of the most massive black holes, with masses >~10^8 Msol. Assuming the jet efficiency depends on spin a, we…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Alejo Martinez-Sansigre , Steve Rawlings

How Supermassive Blackholes (SMBHs) are spun-up is a key issue of modern astrophysics. As an extension of the study in Wang et al. (2016), we here address the issue by comparing the host galaxy properties of nearby ($z<0.05$) radio-selected…

Astrophysics of Galaxies · Physics 2019-11-06 J. Wang , M. Z. Kong , S. F. Liu , D. W. Xu , Q. Zhang , J. Y. Wei

Radio loud active galactic nuclei (AGN) are on average 1000 times brighter in the radio band compared to radio quiet AGN. We investigate whether this radio loud/quiet dichotomy can be due to differences in the spin of the central black…

High Energy Astrophysical Phenomena · Physics 2010-02-21 Alexander Tchekhovskoy , Ramesh Narayan , Jonathan C. McKinney

The distribution of radio to optical fluxes in AGN is bimodal. The physical origin for this bimodality is not understood. In this Letter I describe observational evidence, based on the Boroson & Green PG quasar sample, that the radio…

Astrophysics · Physics 2009-10-31 Ari Laor

While attempts to unify certain classes of AGN using orientation and environmental effects have been successful, it is widely recognized that intrinsic properties of the accreting black hole system also must play a role in determining the…

Astrophysics · Physics 2009-10-31 David L. Meier

Most quasars are known to be radio quiet and according to the ``spin paradigm'', which connects their radio-loudness with the value of the black hole spin, they must harbor very slowly rotating black holes. On the other hand, quasars are…

Astrophysics · Physics 2008-02-03 Rafal Moderski , Marek Sikora , Jean-Pierre Lasota

In this proceeding we explore a pathway to radio-loudness under the hypothesis that retrograde accretion onto giant spinning black holes leads to the launch of powerful jets, as seen in radio loud QSOs and recently in LAT/Fermi and…

High Energy Astrophysical Phenomena · Physics 2010-10-19 M. Dotti , M. Colpi , L. Maraschi , A. Perego , M. Volonteri

Recent advances in general relativistic magnetohydrodynamic modeling of jets offer unprecedented insights into the inner workings of accreting black holes that power the jets in active galactic nuclei (AGN) and other accretion systems. I…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Alexander Tchekhovskoy , Jonathan C. McKinney , Ramesh Narayan

Spins play a crucial role in the appearance, evolution, and occupation fraction of massive black holes (MBHs). To date, observational estimates of MBH spins are scarce, and the assumptions commonly made in such estimates have recently been…

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