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Related papers: Blazar Flaring Rates Measured with GLAST

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The intermediate-frequency-peaked BL Lac object 3C 66A was detected in a flaring state by the Fermi-LAT and VERITAS observatories in October 2008. These data and follow-up observations at other wavelengths create a rich sample of light…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Luis C. Reyes

Blazars, a subclass of active galactic nuclei (AGN), are known to be bright $\gamma$-ray sources, frequently exhibiting active (flaring) periods. The blazar PKS~2155-304 is a high synchrotron-peaked BL Lac object located at redshift…

High Energy Astrophysical Phenomena · Physics 2024-02-26 Hong-Bin Tan , Ruo-Yu Liu , Markus Böttcher

We present the results of a search for stellar flares in the first data release from the Next Generation Transit Survey (NGTS). We have found 610 flares from 339 stars, with spectral types between F8 and M6, the majority of which belong to…

The time evolution of the electromagnetic emission from blazars, in particular high frequency peaked sources (HBLs), displays irregular activity not yet understood. In this work we report a methodology capable of characterizing the time…

High Energy Astrophysical Phenomena · Physics 2010-11-02 E. Resconi , D. Franco , A. Gross , L. Costamante , E. Flaccomio

We present a high time resolution study of the two brightest $\gamma$-ray outbursts from a blazar PKS 1222+216 observed by the \textit{Fermi} Large Area Telescope (LAT) in 2010. The $\gamma$-ray light-curves obtained in four different…

High Energy Astrophysical Phenomena · Physics 2014-11-10 Pankaj Kushwaha , K. P. Singh , S. Sahayanathan

We study the ensemble optical variability of 276 FSRQs and 86 BL Lacs in the Palomar-QUEST Survey with the goal of searching for common fluctuation properties, examining the range of behavior across the sample, and characterizing the…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Anne Bauer , Charles Baltay , Paolo Coppi , Nancy Ellman , Jonathan Jerke , David Rabinowitz , Richard Scalzo

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 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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 J. Leon-Tavares , E. Valtaoja , M. Tornikoski , A. Lahteenmaki , E. Nieppola

Fast Radio Bursts (FRBs) are a mysterious flash phenomenon detected in radio wavelengths with a duration of only a few milliseconds, and they may also have prompt gamma-ray flashes. Here we carry out a blind search for msec-duration…

High Energy Astrophysical Phenomena · Physics 2019-06-07 Shotaro Yamasaki , Tomonori Totani , Norita Kawanaka

Blazars are the brightest and most abundant persistent sources in the extragalactic gamma-ray sky. Due to their significance, they are often observed across various energy bands to explore potential correlations between emissions at…

High Energy Astrophysical Phenomena · Physics 2024-01-22 P. Giommi , N. Sahakyan , D. Israyelyan , M. Manvelyan

The GLAST Burst Monitor (GBM) will detect and localize bursts for the GLAST mission, and provide the spectral and temporal context in the traditional 10 keV to 25 MeV band for the high energy observations by the Large Area Telescope (LAT).…

Astrophysics · Physics 2009-11-10 D. Band , M. Briggs , V. Connaughton , M. Kippen , R. Preece

We carried a detailed spectral and temporal study of blazar, \mbox{PKS\,0903-57} using the \emph{Fermi}-LAT and \emph{Swift}-XRT/UVOT observations, during its brightest flaring period MJD\,58931--58970. During this period, the maximum daily…

High Energy Astrophysical Phenomena · Physics 2021-06-03 Zahir Shah , V. Jithesh , S. Sahayanathan , Naseer Iqbal

The Gamma-ray Large Area Space Telescope (GLAST) is a space-based observatory scheduled to launch in October 2007 with two instruments: (1) the GLAST Burst Monitor (GBM), sensitive to photon energies between 8 keV and 25 MeV and optimized…

Astrophysics · Physics 2008-11-26 Jennifer E. Carson

Using a likelihood analysis (updated since McLaughlin & Cordes 2000) and EGRET detections, upper limits and diffuse background measurements, we find a best-fit luminosity law for the gamma-ray pulsar population. We find that roughly 30 of…

Astrophysics · Physics 2007-05-23 M. A. McLaughlin , J. M. Cordes

Flux distribution is an important tool to understand the variability processes in active galactic nuclei. We now have available a great deal of observational evidences pointing towards the presence of log-normal components in the high…

High Energy Astrophysical Phenomena · Physics 2018-12-18 Carlo Romoli , Nachiketa Chakraborty , Daniela Dorner , Andrew M. Taylor , Michael Blank

Most of the ~50 blazars detected to date at TeV energies (E>0.1 TeV) are high-frequency-peaked BL Lacs (HBLs). Only a handful episodic TeV detections of low- and intermediate-frequency-peaked BL Lacs (LBL/IBLs, with synchrotron peak…

High Energy Astrophysical Phenomena · Physics 2019-08-13 M. Errando

We give a progress report on a snapshot 86 GHz-VLBI survey of the EGRET blazars with the observatories of the CMVA. A high fraction (17/18) of the EGRET blazars were detected on the Pico Veleta-Onsala baseline with a baseline length on the…

Astrophysics · Physics 2016-08-30 Geoffrey C. Bower

We have studied the flare characteristics of 55 AGN at 8 different frequency bands between 4.8 and 230 GHz. Our extensive database enables us to study the various observational properties of flares in these sources and compare our results…

Astrophysics · Physics 2009-11-13 T. Hovatta , E. Nieppola , M. Tornikoski , E. Valtaoja , M. F. Aller , H. D. Aller

We present a study of white light flares from the active M5.5 dwarf Proxima Centauri using the Canadian microsatellite MOST. Using 37.6 days of monitoring data from 2014 and 2015, we have detected 66 individual flare events, the largest…

Solar and Stellar Astrophysics · Physics 2016-10-05 James R. A. Davenport , David M. Kipping , Dimitar Sasselov , Jaymie M. Matthews , Chris Cameron

Three uninterrupted, long (lasting respectively 7, 10, and 10 days) ASCA observations of the well-studied TeV-bright blazars Mrk 421, Mrk 501 and PKS 2155-304 all show continuous strong X-ray flaring. Despite the relatively faint intensity…