A Testable the Stochastic Acceleration Model for Flares in Sagittarius A*

Abstract

The near-IR and X-ray flares in Sagittarius A* are believed to be produced by relativistic electrons via synchrotron and synchrotron self-Comptonization, respectively. These electrons are likely energized by turbulent plasma waves through second-order Fermi acceleration that, in combination with the radiative cooling processes, produces a relativistic Maxwellian distribution in the steady state. This model has four principal parameters, namely the magnetic field B, the electron density n and temperature γ_c mec2, and the size of the flare region R. In the context of stochastic acceleration, the quantities Rn^1/2B and γ_cRn should remain nearly constant in time. Therefore, simultaneous spectroscopic observations in the NIR and X-ray bands can readily test the model, which, if proven to be valid, may be used to determine the evolution of the plasma properties during an eruptive event with spectroscopic observations in either band or simultaneous flux density measurements in both bands. The formulae can be applied to other isolated or confined systems, where electrons are accelerated to relativistic energies by plasma wave turbulence and produce most of the emission via synchrotron processes.

15 pages 4 figures

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Cited by in corpus (27)

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• On the Momentum Diffusion of Radiating Ultrarelativistic Electrons in a Turbulent Magnetic Field
• A Constant Spectral Index for Sagittarius A* During Infrared/X-ray Intensity Variations
• Galactic center at very high-energies
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• Polarized NIR and X-ray Flares from SgrA*
• Concurrent X-ray, near-infrared, sub-millimeter, and GeV gamma-ray observations of Sgr A*
• Modeling mm- to X-ray flare emission from SgrA*
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• Polarized light from Sgr A* in the near-infrared $K_s$-band
• The extreme luminosity states of Sagittarius A*
• Exploring plasma evolution during Sagittarius A* flares
• Testing the Accretion Flow with Plasma Wave Heating Mechanism for Sagittarius a* by the 1.3MM Vlbi Measurements
• Sixteen years of X-ray monitoring of Sagittarius A*: Evidence for a decay of the faint flaring rate from 2013 August, 13 months before a rise in the bright flaring rate
• Flares and variability from Sagittarius A*: five nights of simultaneous multi-wavelength observations
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• Soft gamma-ray constraints on a bright flare from the Galactic Center supermassive black hole
• MC Simulations of the Broadband Spectra of Sagittarius A* through the use of GRMHD
• A Numerical Assessment of Cosmic-ray Energy Diffusion through Turbulent Media
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• Correlation between Flux and Spectral Index during Flares in Sagittarius A*
• Synchrotron Polarization of Relativistic Thermal Electrons