Increased VHE activity from Mrk 501 detected with H.E.S.S.
ATel #6268; Christian Stegmann for the H. E.S. S. collaboration
on 24 Jun 2014; 21:09 UT
Credential Certification: Jean-Philippe Lenain (jlenain@in2p3.fr)
Subjects: Gamma Ray, TeV, VHE, Request for Observations, AGN, Blazar
H.E.S.S. observations of Mrk 501 (z=0.00364) have been carried out during the past week, triggered by flux states above 1 Crab unit reported by the FACT collaboration.
The observations were taken under good weather conditions at very large zenith angles (Z.A. > 60 deg) with the full 5 telescopes array for a total of ~7 hours.
A preliminary online analysis shows a rising flux (> 1 TeV) from June 19th through June 23rd, the nightly averaged significance increasing from ~3 to ~22 standard deviations, with a peak of 15 sigma per one 28-minutes run in the night June 23-24.
Further observations are planned in the coming days and a multi-wavelength coverage is strongly encouraged.
H.E.S.S. is an array of five imaging atmospheric Cherenkov telescopes for the detection of VHE gamma-ray sources located in the Khomas Highlands in Namibia. It was constructed and is operated by researchers from Armenia, Australia, Austria, the Czech Republic, France, Germany, Ireland, Poland,
South Africa, Sweden, UK, and the host country, Namibia.
