Het belang van de voorstelling.

Komossa, Susanne

doi:10.21825/agora.v31i2.2140

Cited by 1 publication

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be noted then that the evaluation of the SMBHs spin is strictly correlated with the "massproblem": the assessment of the precise value of the spin parameter of the BH is connected with the evaluation of the main features of the BH accretion disk system, as the BH accretion rate or the location of the inner edge of the accretion disk. The GWs detection from coalescence of BHs in a binary system may serve, in future, as a further possible method to fix a BH spin parameter (Farr et al 2017, van Putten 2012, 2015, van Putten & Della Valle 2017. However, nowadays this task is often approached in BH-accretion disk framework, by considering the evaluation of the mass accretion rate (connected with the disk luminosity) or, for example, the location of the inner edge of an accreting disk.…”

Section: Introductionmentioning

confidence: 99%

“…It is expected that such SMBHs in AGNs are characterized by a series of multi-accreting episodes during their life-time as a consequence of interaction with the galactic environment, made up by stars and dust, being influenced by the galaxy dynamics. Further example of the complex and rich black hole-active galaxy interaction is known as feedback AGN - (Almeida & Ricci 2017, Hirano et al 2017, Komossa 2015, Ricci et al 2017a, Ricci et al 2017b). These activities may leave traces in the form of matter remnants orbiting the central attractors.…”

Section: Introductionmentioning

confidence: 99%

“…The RAD aggregate is composed by both corotating and counterrotating tori, the limiting case of single accretion torus orbiting the SMBH is also addressed as a special case of the RAD. Each RAD toroidal component is modeled by a perfect fluid with barotropic equation of state and constant specific angular momentum distribution (Abramowicz & Fragile 2013, Pugliese & Montani 2013, 2015. RAD models follow the possibility that several accretion tori can be formed around very compact objects as SMBHs (10 6 − 10 9 M , M being solar masses) in AGNs.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Relating Kerr SMBHs in active galactic nuclei to RADs configurations

Pugliese

Stuchlík

2018

Class. Quantum Grav.

View full text Add to dashboard Cite

There is strong observational evidence that many active galactic nuclei (AGNs) harbour supermassive black holes (SMBHs), demonstrating multi-accretion episodes during their life-time. In such AGNs, corotating and counterrotating tori, or strongly misaligned disks, as related to the central Kerr SMBH spin, can report traces of the AGNs evolution. Here we concentrate on aggregates of accretion disks structures, ringed accretion disks (RADs) orbiting a central Kerr SMBH, assuming that each torus of the RADs is centered in the equatorial plane of the attractor, tori are coplanar and axi-symmetric. Many of the RAD aspects are governed mostly by the spin of the Kerr geometry. We classify Kerr black holes (BHs) due to their dimensionless spin, according to possible combinations of corotating and counterrotating equilibrium or unstable (accreting) tori composing the RADs. The number of accreting tori in RADs cannot exceed n = 2. We present list of 14 characteristic values of the Kerr BH dimensionless spin a governing the classification in whole the black hole range 0 ≤ a ≤ M , uniquely constrained by the RAD properties. The spin values are remarkably close providing an accurate characterization of the Kerr attractors based on the RAD properties. RAD dynamics is richer in the spacetimes of high spin values. One of the critical predictions states that a RAD tori couple formed by an outer accreting corotating and an inner accreting counterrotating torus is expected to be observed only around slowly spinning (a < 0.46M ) BHs. The analysis strongly binds the fluid and BH characteristics providing indications on the situations where to search for RADs observational evidences. Obscuring and screening tori, possibly evident as traces in X-ray spectrum emission, are strongly constrained, eventually ruling out many assumptions used in the current investigations of the screening effects.We expect relevance of our classification of Kerr spacetimes in relation to astrophysical phenomena arising in different stages of AGNs life that could be observed by the planned X-ray satellite observatory ATHENA (Advanced Telescope for High ENergy Astrophysics).

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%