Possible role of massive black holes in the generation of galactic magnetic fields

Nature ◽  
1994 ◽  
Vol 368 (6470) ◽  
pp. 434-436 ◽  
Author(s):  
Sandip K. Chakrabarti ◽  
R. Rosner ◽  
S. I. Vainshtein
Keyword(s):  
Black Holes ◽  
Magnetic Fields ◽  
Massive Black Holes ◽  
Galactic Magnetic Fields

scholarly journals Understanding the origin of radio outflows in Seyfert galaxies using radio polarimetry

2019 ◽  
Vol 15 (S356) ◽  
pp. 247-251
Author(s):  
Biny Sebastian ◽  
Preeti Kharb ◽  
Christopher P. O’ Dea ◽  
Jack F. Gallimore ◽  
Stefi A. Baum ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Radio Emission ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Seyfert Galaxy ◽  
Seyfert Galaxies ◽  
Starburst Galaxies ◽  
Galactic Magnetic Fields ◽  
5 Ghz

AbstractThe role of starburst winds versus active galactic nuclei (AGN) jets/winds in the formation of the kiloparsec scale radio emission seen in Seyferts is not yet well understood. In order to be able to disentangle the role of various components, we have observed a sample of Seyfert galaxies exhibiting kpc-scale radio emission suggesting outflows, along with a comparison sample of starburst galaxies, with the EVLA B-array in polarimetric mode at 1.4 GHz and 5 GHz. The Seyfert galaxy NGC 2639, shows highly polarized secondary radio lobes, not observed before, which are aligned perpendicular to the known pair of radio lobes. The additional pair of lobes represent an older epoch of emission. A multi-epoch multi-frequency study of the starburst-Seyfert composite galaxy NGC 3079, reveals that the jet together with the starburst superwind and the galactic magnetic fields might be responsible for the well-known 8-shaped radio lobes observed in this galaxy. We find that many of the Seyfert galaxies in our sample show bubble-shaped lobes, which are absent in the starburst galaxies that do not host an AGN.

scholarly journals JETS AND OUTFLOWS IN RADIO GALAXIES: IMPLICATIONS FOR AGN FEEDBACK

2012 ◽  
Vol 08 ◽  
pp. 396-399 ◽  
Author(s):  
ELEONORA TORRESI ◽  
PAOLA GRANDI ◽  
ELISA COSTANTINI ◽  
GIORGIO G. C. PALUMBO
Keyword(s):  
Black Holes ◽  
Galaxy Formation ◽  
Surrounding Medium ◽  
Radio Galaxies ◽  
Broad Line ◽  
Jets And Outflows ◽  
Massive Black Holes ◽  
X Ray ◽  
Formation And Evolution

One of the main debated astrophysical problems is the role of the AGN feedback in galaxy formation. It is known that massive black holes have a profound effect on the formation and evolution of galaxies, but how black holes and galaxies communicate is still an unsolved problem. For Radio Galaxies, feedback studies have mainly focused on jet/cavity systems in the most massive and X–ray luminous galaxy clusters. The recent high–resolution detection of warm absorbers in some Broad Line Radio Galaxies allow us to investigate the interplay between the nuclear engine and the surrounding medium from a different perspective. We report on the detection of warm absorbers in two Broad Line Radio Galaxies, 3C 382 and 3C 390.3, and discuss the physical and energetic properties of the absorbing gas. Finally, we attempt a comparison between radio–loud and radio–quiet outflows.

The Role of Gas in the Merging of Massive Black Holes in Galactic Nuclei. II. Black Hole Merging in a Nuclear Gas Disk

2005 ◽  
Vol 630 (1) ◽  
pp. 152-166 ◽  
Author(s):  
Andres Escala ◽  
Richard B. Larson ◽  
Paolo S. Coppi ◽  
Diego Mardones
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Galactic Nuclei ◽  
Massive Black Holes

scholarly journals Formation and early evolution of massive black holes

2006 ◽  
Vol 2 (S238) ◽  
pp. 73-82
Author(s):  
Piero Madau
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Ionization State ◽  
First Stars ◽  
Massive Black Holes ◽  
X Ray ◽  
Hard Radiation ◽  
Low Mass ◽  
The Universe

AbstractThe astrophysical processes that led to the formation of the first seed black holes and to their growth into the supermassive variety that powers bright quasars at z ∼ 6 are poorly understood. In standard ΛCDM hierarchical cosmologies, the earliest massive holes (MBHs) likely formed at redshift z ≳ 15 at the centers of low-mass (M ≳ 5 × 105 M⊙) dark matter “minihalos”, and produced hard radiation by accretion. FUV/X-ray photons from such “miniquasars” may have permeated the universe more uniformly than EUV radiation, reduced gas clumping, and changed the chemistry of primordial gas. The role of accreting seed black holes in determining the thermal and ionization state of the intergalactic medium depends on the amount of cold and dense gas that forms and gets retained in protogalaxies after the formation of the first stars. The highest resolution N-body simulation to date of Galactic substructure shows that subhalos below the atomic cooling mass were very inefficient at forming stars.

scholarly journals Dynamics of galactic nuclei: mass segregation and collisions

2007 ◽  
Vol 3 (S245) ◽  
pp. 211-214 ◽  
Author(s):  
Marc Freitag ◽  
James E. Dale ◽  
Ross P. Church ◽  
Melvyn B. Davies
Keyword(s):  
Black Holes ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
Galactic Centre ◽  
Massive Black Holes ◽  
Giant Stars ◽  
Mass Segregation

AbstractMassive black holes (MBHs) with a mass below ~ 107 M⊙ are likely to reside at the centre of dense stellar nuclei shaped by 2-body relaxation, close interactions with the MBH and direct collisions. In this contribution, we stress the role of mass segregation of stellar-mass black holes into the innermost tenths of a parsec and point to the importance of hydrodynamical collisions between stars. At the Galactic centre, collisions must affect giant stars and some of the S-stars.

scholarly journals Massive Black Holes Regulated by Luminous Blue Variable Mass Loss and Magnetic Fields

2020 ◽  
Vol 900 (2) ◽  
pp. 98
Author(s):  
Jose H. Groh ◽  
Eoin J. Farrell ◽  
Georges Meynet ◽  
Nathan Smith ◽  
Laura Murphy ◽  
...  
Keyword(s):  
Black Holes ◽  
Magnetic Fields ◽  
Mass Loss ◽  
Variable Mass ◽  
Massive Black Holes ◽  
Luminous Blue Variable

scholarly journals Cosmological magnetic braking and the formation of high-redshift, super-massive black holes

2019 ◽  
Vol 486 (2) ◽  
pp. 1629-1640 ◽  
Author(s):  
Kanhaiya L Pandey ◽  
Shiv K Sethi ◽  
Bharat Ratra
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Angular Momentum ◽  
High Redshift ◽  
Potential Well ◽  
Massive Black Holes ◽  
Galactic Magnetic Fields ◽  
Magnetic Braking ◽  
Primordial Magnetic Field ◽  
Tidal Torques

Abstract We study the effect of magnetic braking due to a primordial magnetic field in the context of the formation of massive (≳104M⊙) direct-collapse black holes (DCBHs) at high redshifts. Under the assumption of axial symmetry, we analytically compute the effect of magnetic braking on the angular momentum of gas collapsing into the potential well of massive dark matter haloes (≃107−9M⊙) which are spun up by gravitational tidal torques. We find that a primordial magnetic field of strength B0 ≃ 0.1 nG (comoving) can remove the initial angular momentum gained by the in-falling gas due to tidal torques, thus significantly lowering the angular momentum barrier to the formation of DCBHs. These magnetic field strengths are consistent with the bounds on primordial fields from astrophysical and cosmological measurements and they are large enough to seed observed galactic magnetic fields.

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