Detection of flaring very-high-energy gamma-ray emission from BL Lacertae with the MAGIC telescopes
ATel #16861; David Paneque (Max Planck Institute for Physics), Seiya Nozaki (Max Planck Institute for Physics), Giacomo Bonnoli (INAF), Axel Arbet-Engels (Max Planck Institute for Physics), Silvia Garcia Soto (CIEMAT), Ryo Imazawa (Hiroshima University), on behalf of the MAGIC collaboration
on 10 Oct 2024; 20:35 UT
Credential Certification: David Paneque (dpaneque@mppmu.mpg.de)
Subjects: Gamma Ray, TeV, VHE, AGN, Blazar
The MAGIC Collaboration reports the observation of flaring activity in the very-high-energy (VHE; E>100 GeV) gamma-ray emission from BL Lacertae (22.045 h, 42.278 deg, J2000.0). The preliminary analysis of the MAGIC data taken on 2024 October 10 (MJD 60593.0) indicates a maximum flux around 2e-10 ph/cm^2/s above 250 GeV, which is comparable to the flux from the Crab nebula. The analysis also reveals dramatic intranight variability, with flux changes by more than a factor of two in hour timescales.
BL Lacertae is a blazar located at redshift 0.0686, and it has shown several bright VHE gamma-ray flares in the past (http://tevcat.uchicago.edu/?mode=1&showsrc=118). The MAGIC observations were triggered after a detection of a recent flaring activity in the GeV gamma-ray band by the Fermi-LAT telescope (ATel #16849) on 2024 October 5. Close in time to the Fermi-LAT measurement, a high flux state in the VHE band was reported by the LHAASO (ATel #16850) and VERITAS telescopes (ATel #16854). A subsequent MAGIC observation performed on 2024 October 6 (MJD 60589.9) yielded no indication of a strong flaring activity. The recent MAGIC observations reported in this ATel therefore implies a significant and rapid re-brightening of the gamma-ray emission.
MAGIC observations on BL Lacertae will continue during the next days, and multiwavelength observations are encouraged. The MAGIC contact persons for these observations are D.Paneque (dpaneque@mppmu.mpg.de), S. Nozaki (nozaki@mpp.mpg.de) and G. Bonnoli (giacomo.bonnoli@inaf.it)
The preliminary analysis has been performed by Ryo Imazawa (imazawa@astro.hiroshima-u.ac.jp) and Silvia Garcia Soto (silvia.garcia@ciemat.es). MAGIC is a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes located at the Canary island of La Palma, Spain, and designed to perform gamma-ray astronomy in the energy range from 50 GeV to greater than 50 TeV.
