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Related papers: Flaring variability of Microquasars

200 papers

Using Gaussian process methods, we analyzed the light curves of three extreme solar X-ray flares observed by the RHESSI satellite. Their variability characteristics were then compared with those of HXMT-HE X-ray burst (XRB; in SGR…

High Energy Astrophysical Phenomena · Physics 2025-12-15 Haiyun Zhang , Dahai Yan , Lijuan Dong , Ping Zhang , Ruijing Tang , Jianeng Zhou , Lian Tao , Li Zhang , Niansheng Tang

We compare the gamma-ray photon flux variability of northern blazars in the Fermi/LAT First Source Catalog with 37 GHz radio flux density curves from the Metsahovi quasar monitoring program. We find that the relationship between…

High Energy Astrophysical Phenomena · Physics 2011-10-25 J. Leon-Tavares , E. Valtaoja , M. Tornikoski , A. Lahteenmaki , E. Nieppola

Fast radio bursts (FRBs) are mysterious millisecond-duration radio transients of unknown origin observed at extragalactic distances. It has been long speculated that magnetars are the engine powering repeating bursts from FRB sources, but…

We present results of our analysis of a set of RXTE/PCA observations of X-ray flares/bursts with burst cycle ranging from 30 to 1300 s from the Galactic X-ray transient source GRS 1915+105 during last four years. These flares/bursts can be…

Astrophysics · Physics 2007-05-23 J. S. Yadav , A. R. Rao

In 2008, the blazar Mrk421 entered in a very active phase and was one of the brightest sources in the sky at TeV energies, showing strong and frequent flaring. We searched for gamma-ray emission at energies E > 0.8 TeV during the whole 2008…

High Energy Astrophysical Phenomena · Physics 2009-07-16 G. Di Sciascio

The energy and spectral shape of radio bursts may help us understand the generation mechanism of solar eruptions, including solar flares, CMEs, eruptive filaments, and various scales of jets. The different kinds of flares may have different…

Solar and Stellar Astrophysics · Physics 2022-01-05 Chengming Tan , Karl-Ludwig Klein , Yihua Yan , Satoshi Masuda , Baolin Tan , Jing Huang , Guowu Yuan

High-energy blazar light curves, in X-rays and beyond, have historically preferred a log-normal flux distribution, signifying multiplicative processes either in the jet itself or due to connection(s) with accretion. Here we present 18 year…

High Energy Astrophysical Phenomena · Physics 2026-01-27 Agniva Roychowdhury

We report on broadband observations of CTA 102 ($z=1.037$) during the active states in 2016-2017. In the $\gamma$-ray band, Fermi LAT observed several prominent flares which followed a harder-when-brighter behavior: the hardest photon index…

High Energy Astrophysical Phenomena · Physics 2018-08-22 S. Gasparyan , N. Sahakyan , V. Baghmanyan , D. Zargaryan

We study a solar flare that occurred on September 10, 2002, in active region NOAA 10105 starting around 14:52 UT and lasting approximately 5 minutes in the radio range. The event was classified as M2.9 in X-rays and 1N in H\alpha. Solar…

Solar and Stellar Astrophysics · Physics 2015-06-11 C. G. Giménez de Castro , G. D. Cristiani , P. J. A. Simões , C. H. Mandrini , E. Correia , P. Kaufmann

We study RXTE PCA data for the high mass X-ray binary source SMC X-1 between 2003-10 and 2003-12 when the source was in high states. The source is found to be frequently bursting which can be seen as flares in lightcurves on an average of…

High Energy Astrophysical Phenomena · Physics 2019-01-16 Binay Rai , Pragati Pradhan , Bikash Chandra Paul

With frequent flaring activity of its relativistic jets, Cygnus X-3 is one of the most active microquasars and is the only Galactic black hole candidate with confirmed high energy Gamma-ray emission, thanks to detections by Fermi/LAT and…

The flat-spectrum radio quasar 3C~454.3 throughout the years has presented very high activity phases (flares) in which the different wavebands increase their flux dramatically. In this work, we perform multiwavelength analysis from radio to…

High Energy Astrophysical Phenomena · Physics 2021-01-06 Raúl Antonio Amaya-Almazán , Vahram Chavushyan , Victor Manuel Patiño-Álvarez

We present new results from a continuing 5 GHz search for flaring radio emission from a sample of L and T brown dwarfs, conducted with the 305-m Arecibo radio telescope. In addition to the previously reported flaring from the T6.5-dwarf…

Solar and Stellar Astrophysics · Physics 2016-04-18 Matthew Route , Alexander Wolszczan

Relativistic outflows are believed to be a common feature of black hole X-ray binaries at the lowest accretion rates, when they are in their `quiescent' spectral state. However, we still lack a detailed understanding of how quiescent jet…

High Energy Astrophysical Phenomena · Physics 2019-03-20 R. M. Plotkin , J. C. A. Miller-Jones , L. Chomiuk , J. Strader , S. Bruzewski , A. Bundas , K. R. Smith , J. J. Ruan

The active galactic nucleus 4C +28.07 is a flat spectrum radio quasar, one of the brightest at $\gamma$-ray energies. We study its multi-wavelength emission by analysing $\sim12.3$ years of \textit{Fermi-LAT} data in the $\gamma$-ray band…

High Energy Astrophysical Phenomena · Physics 2022-01-10 Davit Zargaryan , Jonathan Mackey , Thibault Barnouin , Felix Aharonian

We present GMRT observations of the Galactic microquasar GRS 1915+105 at 1.28 GHz for 8 days from 2001 June 18 to July 1. We have seen several isolated radio flares of varying magnitudes (20 - 50 mJy) and durations (6 - 35 min) and we model…

Astrophysics · Physics 2009-11-07 C. H. Ishwara-Chandra , J. S. Yadav , A. Pramesh Rao

The phenomenon of fast radio bursts (FRBs) was discovered in 2007. These are powerful (0.1-100 Jy) single radio pulses with durations of several milliseconds, large dispersion measures, and record high brightness temperatures suggesting…

High Energy Astrophysical Phenomena · Physics 2018-12-14 S. B. Popov , K. A. Postnov , M. S. Pshirkov

The galactic micro-quasar source GRS 1915+105 has been observed with the Indian X-ray Astronomy Experiment (IXAE) several times over a period extending from 1996 to 2000. The source has been observed in different luminosity states and…

Astrophysics · Physics 2007-05-23 S. Naik , P. C. Agrawal , B. Paul , A. R. Rao , J. S. Yadav , S. Seetha

High redshift blazars are among the most powerful non-explosive sources in the Universe and play a crucial role in understanding the evolution of relativistic jets. To understand these bright objects, we performed a detailed investigation…

High Energy Astrophysical Phenomena · Physics 2024-01-29 N. Sahakyan , G. Harutyunyan , S. Gasparyan , D. Israyelyan