A5060355370- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Black Holes and Theoretical Physics
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Relativity and Gravitational Theory
- Particle Accelerators and Free-Electron Lasers
- Gamma-ray bursts and supernovae
- Experimental and Theoretical Physics Studies
- Radio Astronomy Observations and Technology
- Solar and Space Plasma Dynamics
- Galaxies: Formation, Evolution, Phenomena
- Mechanics and Biomechanics Studies
- Stellar, planetary, and galactic studies
- Crystallography and Radiation Phenomena
- Atomic and Subatomic Physics Research
- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Radioactive Decay and Measurement Techniques
- Fractal and DNA sequence analysis
- CCD and CMOS Imaging Sensors
- History and Developments in Astronomy
Czech Academy of Sciences, Institute of Physics
2015-2024
Silesian University in Opava
2015-2024
Max Planck Institute for Radio Astronomy
2024
Centre for Theoretical Physics and Astrophysics
2024
Max Planck Institute for Research on Collective Goods
2023
Universidad Andrés Bello
2023
Millennium Science Initiative
2023
Joint Institute for Nuclear Research
2019-2022
Al-Farabi Kazakh National University
2019-2022
Institute of Nuclear Physics, Polish Academy of Sciences
2021
We present a review of the influence cosmic repulsion and external magnetic fields on accretion disks rotating around black holes jets associated with these configurations. consider both geometrically thin thick disks. show that vacuum energy represented by relic cosmological constant strongly limits extension is for supermassive comparable to largest galaxies, supports collimation at large distances from hole. further demonstrate an field crucially influences fate ionized Keplerian causing...
We study the motion of charged particles in field a rotating black hole immersed into an external asymptotically uniform magnetic field, focusing on epicyclic quasicircular orbits near equatorial plane. Separating circular four qualitatively different classes according to sign canonical angular momentum and orientation Lorentz force, we analyze using so-called force formalism. find analytical solutions for radial profiles velocity, specific momentum, energy dependence black-hole...
In order to test the role of large-scale magnetic fields in quasi-periodic oscillation phenomena observed microquasars, we study oscillatory motion charged particles vicinity a Schwarzschild black hole immersed into an external asymptotically uniform field. We determine fundamental frequencies small harmonic oscillations around stable circular orbits equatorial plane magnetized hole, and discuss radial profiles latitudinal dependence on mass strength demonstrate that assuming relevance...
The Galactic centre supermassive black hole (SMBH), in sharp contrast with its complex environment, is characterized by only three classical parameters -- mass, spin, and electric charge. Its charge poorly constrained. It is, however, usually assumed to be zero because of neutralization due the presence plasma. We revisit question SMBH put realistic limits on value, timescales charging discharging, observable consequences potential, small associated hole. arguments based mass difference...
The study of quasi-periodic oscillations (QPOs) X-ray flux observed in the stellar-mass black hole binaries can provide a powerful tool for testing phenomena occurring strong gravity regime. high frequency (HF) QPOs usually come pairs double peaks which have ratio close to $3:2$. In addition HF QPOs, some sources display simultaneous existence low (LF) Fourier power spectra. We demonstrate that explanation these be well related epicyclic charged particles accretion disks orbiting Kerr holes...
In this Letter, we wish to point out that the distinguishing feature of Magnetic Penrose process (MPP) is its super high efficiency exceeding $100\%$ (which was established in mid 1980s for discrete particle accretion) extraction rotational energy a rotating black hole electromagnetically magnetic field milli Gauss order. Another similar process, which also driven by electromagnetic field, Blandford-Znajek mechanism (BZ), could be envisaged as limit MPP it requires threshold order $10^4$G....
Production and acceleration mechanisms of ultra-high-energy cosmic rays (UHECRs) energy $>10^{20}$eV, clearly beyond the GZK-cutoff limit remain unclear that points to exotic nature phenomena. Recent observations extragalactic neutrino may indicate source UHECRs being an supermassive black hole (SMBH). We demonstrate ultra-efficient extraction from rotating SMBH driven by magnetic Penrose process (MPP) could indeed foot bill. envision ionization neutral particles, such as neutron beta-decay,...
We present a review of the Penrose process and its modifications in relation to Kerr black holes naked singularities (superspinars). introduce standard variant this process, magnetic version connected with magnetized or singularities, electric related electrically charged Schwarzschild holes, radiative particles radiating ergosphere singularities. discuss astrophysical implications variants concentrating attention extreme regime leading extremely large acceleration up ultra-high energy...
Abstract The study of charged particle dynamics in the combined gravitational and magnetic field can provide important theoretical insight into astrophysical processes around black holes. In this paper, we explore parabolic configuration Schwarzschild hole, since paraboloidal shapes lines holes are well motivated by numerical simulations supported observations relativistic jets. Analysing stability bounded orbits using effective potential approach, show possibility existence stable circular...
In many astrophysically relevant situations radiation reaction force acting upon a charge can not be neglected and the question arises about location stability of circular orbits in such regime. Motion point with flat spacetime is described by Lorenz-Dirac (LD) equation, while curved -- DeWitt-Brehme (DWB) equation containing Ricci term tail term. We show that for motion elementary particles vacuum metrics DWB reduced to covariant form LD which we use here. Generically, plagued runaway...
We demonstrate an extraordinary effect of energy gain by a single radiating charged particle inside the ergosphere Kerr black hole in presence magnetic field. solve numerically covariant form Lorentz-Dirac equation reduced from DeWitt-Brehme and analyze evolution ergosphere, where emitted radiation can be negative with respect to distant observer dependence on relative orientation field, spin direction motion. Consequently, leave greater than initial expense hole's rotational energy. In...
The Cosmic Ray Extremely Distributed Observatory (CREDO) is a newly formed, global collaboration dedicated to observing and studying cosmic rays (CR) ray ensembles (CRE): groups of minimum two CR with common primary interaction vertex or the same parent particle. CREDO program embraces testing known CRE scenarios, preparing observe unexpected physics, it also suitable for multi-messenger multi-mission applications. Perfectly matched capabilities, could be formed both within classical models...
Magnetic Penrose process (MPP) is not only the most exciting and fascinating mining rotational energy of black hole but it also favored astrophysically viable mechanism for high sources phenomena. It operates in three regimes efficiency, namely low, moderate ultra, depending on magnetization charging spinning holes astrophysical setting. In this paper, we revisit MPP with a comprehensive discussion its physics different regimes, compare operation other competing mechanisms. We show that...
Recently, near-infrared GRAVITY@ESO observations at $2.2\,\mu{\rm m}$ have announced the detection of three bright "flares" in vicinity Galactic center supermassive black hole (SMBH) that exhibited orbital motion a distance about $6 - 11$ gravitational radii from an $\sim 4\times 10^6\, M_{\odot}$ hole. There are indications presence large-scale, organized component magnetic field center. Electromagnetic effects on flare dynamics were previously not taken into account despite relativistic...
Abstract Buchdahl star is the most compact object without an event horizon and excellent candidate for a black hole mimicker. Unlike holes, rotating can be over-extremal with respect to hole, sustaining larger spin. We show that it also develop ergosphere above threshold spin $$\beta > 1/\sqrt{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>β</mml:mi> <mml:mo>></mml:mo> <mml:mn>1</mml:mn> <mml:mo>/</mml:mo> <mml:msqrt> <mml:mn>2</mml:mn> </mml:msqrt>...
The particle acceleration mechanism in $S^2 \times\mathbb{R}^1$ topology, namely the spacetime of five-dimensional compact black string has been studied. expression center-of-mass energy colliding neutral particles near static found. collision charged moving at innermost stable circular orbit with coming from infinity have considered when is immersed external uniform magnetic field. It shown that unlimited can be approached case extremal rotation which similar to analogous effect Kerr...
In many astrophysical scenarios the charge of black hole is often neglected due to unrealistically large values required for Reissner-Nordstr\"om spacetime metric. However, holes may possess small electric various selective accretion mechanisms. this paper we investigate effect a hypothetical Schwarzschild on ionization freely falling neutral particle and subsequent escape ionized from hole. We show that energy can grow ultrahigh discuss distinguishing signatures acceleration by weakly...
We discuss the problem of third black hole parameter, an electric charge. While mass and spin holes are frequently considered in majority publications, charge is often neglected implicitly set identically to zero. However, both classical relativistic processes can lead a small non-zero holes. When dealing with neutral particles photons, zero good approximation. On other hand, even significantly influence motion charged particles, particular cosmic rays, vicinity Therefore, we stress that...
Abstract Propagation of ultra-high energy photons in the solar magnetosphere gives rise to cascades comprising thousands photons. We study cascade development using Monte Carlo simulations and find that are spatially extended over millions kilometers on plane distant from Sun by 1 AU. estimate chance detection considering upper limits current cosmic rays observatories order provide an optimistic rate 0.002 events per year a chosen ring-shaped region around Sun. compare results which use two...
In a recent study devoted to the influence of electromagnetic radiation reaction on motion radiating charged particles in magnetized black hole spacetimes authors claim that tail term cannot be neglected complete DeWitt–Brehme equation, putting into doubt previous papers where such an approximation was used. Here, we demonstrate by using simple dimensional arguments statement is misleading many astrophysically relevant situations. case relativistic electrons moving around stellar-mass hole,...
Abstract Recently, it has been argued that the high-frequency quasi-periodic oscillations (QPOs) observed in black hole systems of various scales mass cases supermassive holes (SMBH) are not consistent with any simple physical models, based on frequencies geodesic epicyclic motion (Smith et al. 2021, ApJ, 906, 92). We test if such a disease can be simply cured by models modified effect electromagnetic interaction slightly charged orbiting matter, large-scale magnetic fields values around...
We present the purpose, long-term development vision, basic design, detection algorithm and preliminary results obtained with Cosmic Ray Extremely Distributed Observatory (CREDO) Detector mobile application. The CREDO app related infrastructure are unique in terms of their scale, targeting many form-factors open-access philosophy. This philosophy translates to open-source code app, both data inflow as well consumption above all, citizen science that means is open all who wish participate...