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Related papers: Self-Organized Criticality in Stellar Flares

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The Kepler mission identified huge flares on various stars including some of solar type. These events are substantially more energetic than solar flares, and so they are referred to as superflares. Even a small probability of such a…

Solar and Stellar Astrophysics · Physics 2018-08-08 M. M. Katsova , L. L. Kitchatinov , D. Moss , K. Olah , D. D. Sokoloff

Many natural phenomena exhibit power law behaviour in the distribution of event size. This scaling is successfully reproduced by Self Organized Criticality (SOC). On the other hand, temporal occurrence in SOC models has a Poisson-like…

Statistical Mechanics · Physics 2009-11-11 Eugenio Lippiello , Lucilla de Arcangelis , Cataldo Godano

Since the analogy between laser oscillation and second-order phase transition was indicated in the 1970s, dynamical fluctuations on lasing threshold inherent in critical phenomena have gained significant interest. Here, we numerically and…

Optics · Physics 2025-02-27 Tomoaki Niiyama , Satoshi Sunada

Recent detection of superflares on solar-type stars by Kepler mission raised a possibility that they can be associated with energetic coronal mass ejections (CMEs) and energetic particle events (SEPs). These space weather events can impact…

Solar and Stellar Astrophysics · Physics 2019-06-26 Shuai Fu , Yong Jiang , Vladimir Airapetian , Junxiang Hu , Gang Li , Gary Zank

X-ray flares have routinely been observed from the supermassive black hole, Sagittarius A$^\star$ (Sgr A$^\star$), at our Galactic center. The nature of these flares remains largely unclear, despite of many theoretical models. In this…

High Energy Astrophysical Phenomena · Physics 2015-09-16 Ya-Ping Li , Feng Yuan , Qiang Yuan , Q. Daniel Wang , P. F. Chen , Joseph Neilsen , Taotao Fang , Shuo Zhang , Jason Dexter

Recent imaging observations of EUV line emissions have shown evidence for frequent flare-like events in a majority of the pixels in quiet regions of the solar corona. The changes in coronal emission measure indicate impulsive heating of new…

Astrophysics · Physics 2009-11-07 Arnold O. Benz , Sam Krucker

The stellar surface mass density profiles at the centers of typical ~L* and lower-mass spheroids exhibit power law 'cusps' with $\Sigma \propto R^(-n)$, where 0.5<n<1 for radii ~1-100 pc. Observations and theory support models in which…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-22 Philip F. Hopkins , Eliot Quataert

Two models of binary fragmentation are introduced in which a time dependent transition size produces two regions of fragment sizes above and below the transition size. In the models we consider a fixed rate of fragmentation for the largest…

Statistical Mechanics · Physics 2009-10-31 Z. Tavassoli , A. Esmaeilnia Shirvani

We have analyzed the spatial distribution of galaxies from the release of the Sloan Digital Sky Survey of galactic redshifts (SDSS DR7), applying the complete correlation function (conditional density), two-point conditional density…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 A. O. Verevkin , Yu. L. Bukhmastova , Yu. V. Baryshev

In this paper we study a simple model of a purely excitatory neural network that, by construction, operates at a critical point. This model allows us to consider various markers of criticality and illustrate how they should perform in a…

Neurons and Cognition · Quantitative Biology 2013-05-17 Timothy J. Taylor , Caroline Hartley , Péter L. Simon , Istvan Z Kiss , Luc Berthouze

We investigate whether open clusters (OCs) tend to energy equipartition, by means of direct N-body simulations with a broken power-law mass function. We find that the simulated OCs become strongly mass segregated, but the local velocity…

Solar and Stellar Astrophysics · Physics 2016-05-25 Mario Spera , Michela Mapelli , Robin D. Jeffries

Context. X-ray flares are common phenomena in pre-main sequence stars. Their analysis gives insights into the physics at work in young stellar coronae. The Orion Nebula Cluster offers a unique opportunity to study large samples of young low…

Astrophysics · Physics 2009-11-13 M. Caramazza , E. Flaccomio , G. Micela , F. Reale , S. J. Wolk , E. D. Feigelson

Wide-field high precision photometric surveys such as Kepler have produced reams of data suitable for investigating stellar magnetic activity of cooler stars. Starspot activity produces quasi-sinusoidal light curves whose phase and…

Solar and Stellar Astrophysics · Physics 2017-09-20 Helen A. C. Giles , Andrew Collier Cameron , Raphaëlle D. Haywood

The orbital distribution of giant planets is crucial for understanding how terrestrial planets form and predicting yields of exoplanet surveys. Here, we derive giant planets occurrence rates as a function of orbital period by taking into…

Solar and Stellar Astrophysics · Physics 2019-04-03 Rachel B. Fernandes , Gijs D. Mulders , Ilaria Pascucci , Christoph Mordasini , Alexandre Emsenhuber

Power law distributions of macroscopic observables are ubiquitous in both the natural and social sciences. They are indicative of correlated, cooperative phenomena between groups of interacting agents at the microscopic level. In this paper…

Condensed Matter · Physics 2009-11-07 P Ormerod , C Mounfield

In this study, new observations and some results of statistical analyses are presented. The largest flare data set of DO Cep in the literature has been obtained with 89 flares detected in 67.61 hours of U-band flare patrol. First of all,…

Solar and Stellar Astrophysics · Physics 2012-06-28 H. A. Dal

Analyzing time series of fluxes from stars, known as stellar light curves, can reveal valuable information about stellar properties. However, most current methods rely on extracting summary statistics, and studies using deep learning have…

Instrumentation and Methods for Astrophysics · Physics 2024-06-18 Jia-Shu Pan , Yuan-Sen Ting , Yang Huang , Jie Yu , Ji-Feng Liu

We study simultaneous price drops of real stocks and show that for high drop thresholds they follow a power-law distribution. To reproduce these collective downturns, we propose a minimal self-organized model of cascade spreading based on a…

Physics and Society · Physics 2015-03-13 Stanislao Gualdi , Matus Medo , Yi-Cheng Zhang

Stellar flares are energetic events occurring in stellar atmospheres. They have been observed on various stars using photometric light curves and spectra. On some cool stars, flares tend to release substantially more energy compared to…

Solar and Stellar Astrophysics · Physics 2023-01-25 Jiří Wollmann , Petr Heinzel , Petr Kabáth

When the probability of measuring a particular value of some quantity varies inversely as a power of that value, the quantity is said to follow a power law, also known variously as Zipf's law or the Pareto distribution. Power laws appear…

Statistical Mechanics · Physics 2019-09-23 M. E. J. Newman