학술논문

A Luminous and Isolated Gamma-Ray Flare from the Blazar B2 1215+30
Document Type
Source
Astrophysical Journal. 836(2)
Subject
BL Lacertae objects: individual (B2 1215+30
VER J1217+301)
galaxies: active
galaxies: jets
galaxies: nuclei
gamma rays: galaxies
Astroparticle Physics
Astropartikelfysik
Language
English
ISSN
0004-637X
1538-4357
Abstract
B2 1215+30 is a BL-Lac-type blazar that was first detected at TeV energies by the MAGIC atmospheric Cherenkov telescopes and subsequently confirmed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory with data collected between 2009 and 2012. In 2014 February 08, VERITAS detected a large-amplitude flare from B2. 1215+30 during routine monitoring observations of the blazar 1ES. 1218+304, located in the same field of view. The TeV flux reached 2.4 times the Crab Nebula flux with a variability timescale of <3.6 hr. Multiwavelength observations with Fermi-LAT, Swift, and the Tuorla Observatory revealed a correlated high GeV flux state and no significant optical counterpart to the flare, with a spectral energy distribution where the gamma-ray luminosity exceeds the synchrotron luminosity. When interpreted in the framework of a onezone leptonic model, the observed emission implies a high degree of beaming, with Doppler factor delta > 10, and an electron population with spectral index p < 2.3.