中文
相关论文

相关论文: Blazar Flaring Rates Measured with GLAST

200 篇论文

The blazar 4C 31.03 recently underwent a major gamma-ray outburst at the beginning of 2023 after a prolonged quiescent phase. Fermi-LAT reported a daily average flux of 5x10^-6 phs cm^-2 s^-1, which is about 60 times its average value. We…

高能天体物理现象 · 物理学 2024-04-16 Aminabi Thekkoth , Baheeja C , S Sahayanathan , C D Ravikumar

BL Lacertae is a blazar at the redshift of z = 0.069, eponym of the BL Lac blazar type. It is also a prototype of the low-frequency-peaked BL Lac (LBL) subclass. It was first detected in sub-TeV gamma-ray range by MAGIC in 2005. In 2015,…

Blazars are a subclass of active galactic nuclei with relativistic jets pointing toward the observer. They are notable for their flux variability at all observed wavelengths and timescales. Together with simultaneous measurements at lower…

高能天体物理现象 · 物理学 2025-02-21 Hermann Stolte , Jonas Sinapius , Iftach Sadeh , Elisa Pueschel , Matthias Weidlich , David Berge

Giant flares from magnetars can reach, for a fraction of a second, luminosities greater than 10$^{47}$ erg s$^{-1}$ in the hard X-ray/soft $\gamma$-ray range. This makes them visible at distances of several megaparsecs. However, at…

高能天体物理现象 · 物理学 2024-11-06 Dominik P. Pacholski , Edoardo Arrigoni , Sandro Mereghetti , Ruben Salvaterra

We investigate the spectral properties of the brightest gamma-ray flares of blazars detected by the Fermi Large Area Telescope. We search for the presence of spectral breaks and measure the spectral curvature on typical time scales of a few…

高能天体物理现象 · 物理学 2015-06-24 Susanna Kohler , Krzysztof Nalewajko

In Spring 2005, the blazar 3C454.3 underwent a dramatic outburst at all wavelengths from mm to X-rays. This prompted INTEGRAL observations, accomplished in 15-18 May 2005. The source was detected by the INTEGRAL instruments from 3 to 200…

天体物理学 · 物理学 2009-11-11 Elena Pian , Luigi Foschini , Volker Beckmann

We study the spectral and temporal behavior of X-ray flares from the active M-dwarf EV Lac in 200 ks of exposure with the Chandra/HETGS. We derive flare parameters by fitting an empirical function which characterizes the amplitude, shape,…

高能天体物理现象 · 物理学 2015-05-19 David P. Huenemoerder , Norbert S. Schulz , Paola Testa , Jeremy J. Drake , Rachel A. Osten , Fabio Reale

The new analysis variable xi, shown to be powerful on the data taken with the final configuration of CELESTE, has been applied to data taken with previous detector configurations. First, the analysis is validated on Crab observations, and…

天体物理学 · 物理学 2007-05-23 E. Brion , the CELESTE collaboration

The EGRET experiment aboard the Compton Gamma-Ray Observatory (CGRO) has observed at energies above 100 MeV strong gamma-ray flares with short-term time variability from the gamma-ray blazars 3C 279 and PKS 1622-297. During these flaring…

We perform a blind search for the variability of the gamma-ray sky in the energy range E>1 GeV using 308 weeks of the Fermi-LAT data. We use the technique based on the comparison of the weekly photon counts and exposures in sky pixels by…

高能天体物理现象 · 物理学 2015-12-22 M. S. Pshirkov , G. I. Rubtsov

We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was observed during a 34.6-minute exposure,…

In 2008 the blazar Markarian 421 entered a very active phase and was one of the brightest sources in the sky at TeV energies, showing frequent flaring episodes. Using the data of ARGO-YBJ, a full coverage air shower detector located at…

高能天体物理现象 · 物理学 2015-05-18 G. Aielli et al.

We present optical, X-ray, high energy ($\lessapprox 30$ GeV) and very high energy ($\gtrapprox 100$ GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 and June 23. A high energy $\gamma$-ray signal…

The Large Area Telescope (LAT) instrument onboard GLAST offers a tremendous opportunity for future blazar studies. In order to fully benefit from its capabilities and to maximize the scientific return from the LAT, it is of great importance…

天体物理学 · 物理学 2009-06-23 L. Fuhrmann , J. A. Zensus , T. P. Krichbaum , E. Angelakis , A. C. S. Readhead

The ANTARES telescope observes a full hemisphere of the sky all the time with a duty cycle close to 100%. This makes it well suited for an extensive observation of neutrinos produced in astrophysical transient sources. In the surrounding…

高能天体物理现象 · 物理学 2017-10-20 Agustín Sánchez-Losa

The Fermi-LAT has observed new gamma-ray flares from the blazar B0218+357 during July 2014. While no significant change in the gamma-ray spectrum has been previously observed through the flaring phase in late-2012, during this recent high…

高能天体物理现象 · 物理学 2015-02-12 S. Buson , C. C. Cheung , S. Larsson , J. D. Scargle

Blazars are a kind of active galactic nuclei (AGN) in which a relativistic jet is considered to be directed along the line of sight. They are characterized by strong and rapid variability of the flux and high polarization. We performed a…

高能天体物理现象 · 物理学 2009-12-21 Y. Ikejiri , M. Uemura , M. Sasada , K. Sakimoto , R. Ito , M. Yamanaka , A. Arai , Y. Fukazawa , T. Ohsugi , K. S. Kawabata

Blazars are known to exhibit variability across a broad range of timescales. This behavior can include periodicity in their $\gamma$-ray emission, whose clear detection remains an ongoing challenge, partly due to the inherent stochasticity…

高能天体物理现象 · 物理学 2025-07-08 P. Peñil , M. Ajello , S. Buson , A. Domínguez , J. R. Westernacher-Schneider , A. Rico , S. Adhikari , J. Zrake

Blazars, the peculiar class of active galactic nuclei (AGN), are known to show flux variations across the accessible electromagnetic spectrum. Though they have been studied extensively for their flux variability characteristics across…

The gamma-ray emission offers a powerful diagnostic tool to probe jets and their surroundings in flat spectrum radio quasars (FSRQ). In particular, sources emitting at high energies (>10 GeV) give us the strongest constraints. This…

高能天体物理现象 · 物理学 2015-06-18 L. Pacciani , F. Tavecchio , I. Donnarumma , A. Stamerra , L. Carrasco , E. Recillas , A. Porras , M. Uemura