scholarly journals Structure formation of black hole jets triggered by electron-scale physics

2020 ◽  
Author(s):  
Tomohisa Kawashima ◽  
Seiji Ishiguro ◽  
Toseo Moritaka ◽  
Ritoku Horiuchi ◽  
Kohji Tomisaka
Keyword(s):  
Black Hole ◽  
Structure Formation ◽  
Elliptical Galaxy ◽  
High Energy ◽  
Shear Instability ◽  
Relativistic Jets ◽  
Ridge Structure ◽  
Sheath Region ◽  
High Energy Electrons ◽  
Relativistic Jet

Abstract Jets are ubiquitous in the universe[1,2]. The radio jet is a beamed plasma flow with relativistic speed accelerated by a supermassive black hole in some galaxies. Recent observations of the relativistic jet in the elliptical galaxy M87 have discovered a triple-ridge sub-structure in the jet at a distance of one thousand Schwartzchild radius from the black hole [3,4]. The triple-ridge structure may be the first strong evidence of the spine-sheath structure consisting of the fast spine region (jet spine) and relatively slow sheath region (jet sheath), which was hypothetically introduced to explain observational features in various unresolved relativistic jets [5,6]. However, the formation mechanism of such a spine-brightened jet is quite enigmatic. Here we report that the combination of the magnetic pinching force induced by an electron-scale shear-instability called Mushroom instability[7] and the high-energy electron ejections by the subsequent magnetic reconnection leads to the drastic accumulation of high-energy electrons in the center of the cylindrical jet. The concentration of high-energy electrons towards the jet center indicates the appearance of bright jet-spine as observed in M87. Thus, the electron-scale, microscopic processes would play an important role in the structure formation and generation of high-energy components in the relativistic jets. Rererences: [1] Frank, A. etal. Jets and Outflows from Star to Cloud: Observations ConfrontTheory. InBeuther, H., Klessen, R. S., Dullemond, C. P. & Henning, T. (eds.) Protostars and Planets VI, 451 (2014). [2] Blandford, R., Meier, D. & Readhead, A. Relativistic Jets from Active Galactic Nuclei. ARA&A 57, 467–509 (2019). [3] Asada, K., Nakamura, M. & Pu, H.-Y. Indication of the Black Hole Powered Jet in M87 by VSOP Observations. ApJ833, 56 (2016). [4] Hada, K. The Structure and Propagation of the Misaligned Jet M87. Galaxies 5, 2 (2017). [5] Laing, R. A. & Bridle, A. H. Relativistic models and the jet velocity field in the radio galaxy3C 31. MNRAS 336, 328–352 (2002). [6] Ghisellini, G., Tavecchio, F. & Chiaberge, M. Structured jets in TeV BL Lac objectsand radiogalaxies. Implications for the observed properties. A&A 432, 401–410 (2005). [7] Alves, E. P., Grismayer, T., Fonseca, R. A. & Silva, L. O. Transverse electron-scale instability in relativistic shear flows. PhRvE 92, 021101 (2015).

scholarly journals What can Fermi LAT observation of the Galactic Centre tell us about its active past?

2016 ◽  
Vol 12 (S324) ◽  
pp. 115-118
Author(s):  
Gabrijela Zaharijas ◽  
Jovana Petrović ◽  
Pasquale Serpico
Keyword(s):  
Black Hole ◽  
Gamma Ray ◽  
Galactic Center ◽  
High Energy ◽  
Galactic Centre ◽  
Massive Black Hole ◽  
The Past ◽  
High Energy Electrons ◽  
Inverse Compton ◽  
Past Activity

AbstractThe Fermi-LAT gamma-ray data in the inner Galaxy region show several prominent features possibly related to the past activity of the Milky Way’s super massive black hole. At a large, 50 deg scale, the Fermi LAT revealed symmetric hour glass structures with hard energy spectra extending up to 100 GeV (and dubbed ‘the Fermi bubbles’). More recently and closer to the Galactic centre, at the 10 deg scale, several groups have claimed evidence for excess gamma-ray emission that appears symmetric around the Galactic center and has an energy spectrum peaking at few GeVs. We explore here the possibility that this emission originates in inverse Compton emission from high-energy electrons produced in a short duration, burst-like event injecting 1052 − 1053 erg, roughly 106 yrs ago. Several lines of evidence suggest that a series of ‘burst like’ events happened in the vicinity of our black hole in the past and gamma-ray observations may offer a new view of that scenario.

scholarly journals Relativistic Jets from AGN Viewed at Highest Angular Resolution

Galaxies ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
Kazuhiro Hada
Keyword(s):  
Black Hole ◽  
Spatial Scales ◽  
High Energy ◽  
Rapid Expansion ◽  
Relativistic Jets ◽  
Energy Bands ◽  
Theoretical Understanding ◽  
Broadband Emission ◽  
Long Baseline ◽  
Magnetohydrodynamic Simulations

Accreting supermassive black holes in active galactic nuclei (AGN) produce powerful relativistic jets that shine from radio to GeV/TeV γ-rays. Over the past decade, AGN jets have extensively been studied in various energy bands and our knowledge about the broadband emission and rapid flares are now significantly updated. Meanwhile, the progress of magnetohydrodynamic simulations with a rotating black hole have greatly improved our theoretical understanding of powerful jet production. Nevertheless, it is still challenging to observationally resolve such flaring sites or jet formation regions since the relevant spatial scales are tiny. Observations with very long baseline interferometry (VLBI) are currently the only way to directly access such compact scales. Here we overview some recent progress of VLBI studies of AGN jets. As represented by the successful black hole shadow imaging with the Event Horizon Telescope, the recent rapid expansion of VLBI capability is remarkable. The last decade has also seen a variety of advances thanks to the advent of RadioAstron, GMVA, new VLBI facilities in East Asia as well as to the continued upgrade of VLBA. These instruments have resolved the innermost regions of relativistic jets for a number of objects covering a variety of jetted AGN classes (radio galaxies, blazars, and narrow-line Seyfert 1 galaxies), and the accumulated results start to establish some concrete (and likely universal) picture on the collimation, acceleration, recollimation shocks, magnetic field topology, and the connection to high-energy flares in the innermost part of AGN jets.

scholarly journals Waves in Poynting-flux dominated jets

2010 ◽  
Vol 6 (S275) ◽  
pp. 77-81
Author(s):  
John G. Kirk ◽  
Iwona Mochol
Keyword(s):  
Black Hole ◽  
Lorentz Factor ◽  
High Energy ◽  
Acceleration Phase ◽  
Gravitational Radius ◽  
Rapid Variability ◽  
Poynting Flux ◽  
Electromagnetic Cascade ◽  
Relativistic Jet ◽  
High Energy Emission

AbstractHigh-energy emission from blazars is thought to arise in a relativistic jet launched by a supermassive black hole. The rapid variability of the emission suggests that structure of length scale smaller than the gravitational radius of the central black hole is imprinted on the jet as it is launched, and modulates the radiation released after it has been accelerated to high Lorentz factor. We describe a mechanism which can account for the acceleration of the jet, and for the rapid variability of the radiation, based on the propagation characteristics of nonlinear waves in charge-starved, polar jets. These exhibit a delayed acceleration phase, that kicks-in when the inertia associated with the wave currents becomes important. The time structure imprinted on the jet at launch modulates the photons produced by the accelerating jet provided that the electromagnetic cascade in the black-hole magnetosphere is not prolific.

scholarly journals Fifty Years of Energy Extraction from Rotating Black Hole: Revisiting Magnetic Penrose Process

Universe ◽  
2019 ◽  
Vol 5 (5) ◽  
pp. 125 ◽  
Author(s):  
Arman Tursunov ◽  
Naresh Dadhich
Keyword(s):  
Black Hole ◽  
Process Mining ◽  
Thought Experiment ◽  
High Energy ◽  
Radio Bursts ◽  
Ultra High Energy ◽  
Relativistic Jets ◽  
High Energy Cosmic Rays ◽  
Penrose Process ◽  
Viable Mechanism

Magnetic Penrose process (MPP) is not only the most exciting and fascinating process mining the rotational energy of black hole but it is also the favored astrophysically viable mechanism for high energy sources and phenomena. It operates in three regimes of efficiency, namely low, moderate and ultra, depending on the magnetization and charging of spinning black holes in astrophysical setting. In this paper, we revisit MPP with a comprehensive discussion of its physics in different regimes, and compare its operation with other competing mechanisms. We show that MPP could in principle foot the bill for powering engine of such phenomena as ultra-high-energy cosmic rays, relativistic jets, fast radio bursts, quasars, AGNs, etc. Further, it also leads to a number of important observable predictions. All this beautifully bears out the promise of a new vista of energy powerhouse heralded by Roger Penrose half a century ago through this process, and it has today risen in its magnetically empowered version of mid 1980s from a purely thought experiment of academic interest to a realistic powering mechanism for various high-energy astrophysical phenomena.

scholarly journals The central pc-scale region in blazars: insights from multi-band observations

2013 ◽  
Vol 9 (S304) ◽  
pp. 257-260
Author(s):  
Tigran G. Arshakian ◽  
Vahram Chavushyan
Keyword(s):  
Black Hole ◽  
High Energy ◽  
Opening Angle ◽  
Radiation Mechanisms ◽  
Long Baseline ◽  
Empirical Relations ◽  
Relativistic Jet ◽  
Line Region ◽  
Γ Ray ◽  
Very Long Baseline Array

AbstractThe empirical relations in the black hole-accretion disk-relativistic jet system and physical processes behind these relations are still poorly understood, partly because they operate close to the black hole within the central light year. Very long baseline array (VLBA) provides unparalleled resolution at 15 GHz with which to observe the jet components at sub-milliarcsecond scales, corresponding to sub-pc-scales for local blazars. We discuss the jet inner structure of blazars, location and radiation mechanisms operating in the innermost parsec-scale region of blazars, and evidence for jet-excited broad-line region (BLR) ouflowing downstream the jet. Outflowing BLR can provide necessary conditions for production of high energy emission along the jet between the base of the jet and the BLR and far beyond the BLR as evidenced by recent observations. Flat spectrum quasars and low synchrotron peaked sources are the most likely objects to host the outfllowing BLR. From the γ-ray absorption arguments, we propose that the jet-excited region of the outflowing BLR in quasars is small and/or gas filling factor is low, and that the orientation and opening angle of the outflowing BLR can lead to relevant γ-ray absorption features observed in quasars.

scholarly journals Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

2019 ◽  
Vol 209 ◽  
pp. 01007
Author(s):  
Francesco Nozzoli
Keyword(s):  
Electron Flux ◽  
Space Station ◽  
Cosmic Ray ◽  
High Energy ◽  
Precision Measurements ◽  
High Energy Electrons ◽  
Electrons And Positrons ◽  
Positron Flux ◽  
Rigidity Dependence ◽  
Alpha Magnetic Spectrometer

Precision measurements by AMS of the fluxes of cosmic ray positrons, electrons, antiprotons, protons as well as their rations reveal several unexpected and intriguing features. The presented measurements extend the energy range of the previous observations with much increased precision. The new results show that the behavior of positron flux at around 300 GeV is consistent with a new source that produce equal amount of high energy electrons and positrons. In addition, in the absolute rigidity range 60–500 GV, the antiproton, proton, and positron fluxes are found to have nearly identical rigidity dependence and the electron flux exhibits different rigidity dependence.

scholarly journals WISDOM project – VII. Molecular gas measurement of the supermassive black hole mass in the elliptical galaxy NGC 7052

2021 ◽  
Vol 503 (4) ◽  
pp. 5984-5996
Author(s):  
Mark D Smith ◽  
Martin Bureau ◽  
Timothy A Davis ◽  
Michele Cappellari ◽  
Lijie Liu ◽  
...  
Keyword(s):  
Black Hole ◽  
Hubble Space Telescope ◽  
Elliptical Galaxy ◽  
Continuum Emission ◽  
Molecular Gas ◽  
Supermassive Black Hole ◽  
Gas Kinematics ◽  
Long Baseline ◽  
Gas Measurement ◽  
Strong Gradient

ABSTRACT Supermassive black hole (SMBH) masses can be measured by resolving the dynamical influences of the SMBHs on tracers of the central potentials. Modern long-baseline interferometers have enabled the use of molecular gas as such a tracer. We present here Atacama Large Millimeter/submillimeter Array observations of the elliptical galaxy NGC 7052 at 0${^{\prime\prime}_{.}}$11 ($37\,$pc) resolution in the 12CO(2-1) line and $1.3\,$ mm continuum emission. This resolution is sufficient to resolve the region in which the potential is dominated by the SMBH. We forward model these observations, using a multi-Gaussian expansion of a Hubble Space Telescope F814W image and a spatially constant mass-to-light ratio to model the stellar mass distribution. We infer an SMBH mass of $2.5\pm 0.3\times 10^{9}\, \mathrm{M_\odot }$ and a stellar I-band mass-to-light ratio of $4.6\pm 0.2\, \mathrm{M_\odot /L_{\odot ,I}}$ (3σ confidence intervals). This SMBH mass is significantly larger than that derived using ionized gas kinematics, which however appears significantly more kinematically disturbed than the molecular gas. We also show that a central molecular gas deficit is likely to be the result of tidal disruption of molecular gas clouds due to the strong gradient in the central gravitational potential.

scholarly journals Polar Middle Atmospheric Responses to Medium Energy Electron (MEE) Precipitation Using Numerical Model Simulations

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 133
Author(s):  
Ji-Hee Lee ◽  
Geonhwa Jee ◽  
Young-Sil Kwak ◽  
Heejin Hwang ◽  
Annika Seppälä ◽  
...  
Keyword(s):  
Climate Model ◽  
Middle Atmosphere ◽  
Meridional Circulation ◽  
Stratospheric Ozone ◽  
High Energy ◽  
Chemical Changes ◽  
Temperature Changes ◽  
Mesospheric Temperature ◽  
High Energy Electrons ◽  
Circulation Changes

Energetic particle precipitation (EPP) is known to be an important source of chemical changes in the polar middle atmosphere in winter. Recent modeling studies further suggest that chemical changes induced by EPP can also cause dynamic changes in the middle atmosphere. In this study, we investigated the atmospheric responses to the precipitation of medium-to-high energy electrons (MEEs) over the period 2005–2013 using the Specific Dynamics Whole Atmosphere Community Climate Model (SD-WACCM). Our results show that the MEE precipitation significantly increases the amounts of NOx and HOx, resulting in mesospheric and stratospheric ozone losses by up to 60% and 25% respectively during polar winter. The MEE-induced ozone loss generally increases the temperature in the lower mesosphere but decreases the temperature in the upper mesosphere with large year-to-year variability, not only by radiative effects but also by adiabatic effects. The adiabatic effects by meridional circulation changes may be dominant for the mesospheric temperature changes. In particular, the meridional circulation changes occasionally act in opposite ways to vary the temperature in terms of height variations, especially at around the solar minimum period with low geomagnetic activity, which cancels out the temperature changes to make the average small in the polar mesosphere for the 9-year period.

The Effects of High-Energy Electrons on the Charging of Spacecraft Dielectrics

1979 ◽  
Vol 26 (6) ◽  
pp. 5101-5106 ◽  
Author(s):  
M. J. Treadaway ◽  
C. E. Mallon ◽  
T. M. Flanagan ◽  
R. Denson ◽  
E. P. Wenaas
Keyword(s):  
High Energy ◽  
High Energy Electrons
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