Discovery of Very High Energy Gamma-Ray Emission from BL Lac object RX J1136.5+6737 by the MAGIC Telescopes

ATel #6062; Razmik Mirzoyan (Max-Planck-Institute for Physics) on behalf of the MAGIC Collaboration
on 11 Apr 2014; 11:11 UT
Credential Certification: Razmik Mirzoyan (Razmik.Mirzoyan@mpp.mpg.de)

Tweet

The MAGIC collaboration reports the discovery of very high energy (VHE; E>100 GeV) gamma-ray emission from RX J1136.5+6737 (a.k.a. RBS 1004) (RA: 11:36:30.1 DEC: +67:37:04, J2000) at redshift z=0.1342. RX J1136.5+6737 is an X-ray bright high-peaked frequency BL Lac object as listed in the MAXI 3-year catalog (Hiroi et al. 2013), which includes 13 BL Lacs (all HBLs and 9 TeV HBLs). The source has also been detected by Fermi-LAT, in the Second Fermi-LAT source catalog (2FGL; Nolan et al. 2012) with a hard photon index 1.68+/-0.12, and belongs to the first Fermi-LAT catalog of >10 GeV sources (1FHL; Ackermann et al, 2013), showing bright (photon flux = 11.7e-11 ph cm^-2 s^-1) emission above 10 GeV, and identified as a good candidate for VHE detection. RX J1136.5+6737 was observed with the MAGIC telescopes starting on 2014 January 29. Data taken up to 2014 April 3 (about 20 hours in total) yielded a source detection with a statistical significance of more than 5 standard deviations. The averaged flux measured by MAGIC during the 2014 observations corresponded to about 1.5% of the Crab nebula at energies above 200 GeV. MAGIC is planning to resume observations of the source on April 18th (right after the full-moon break). Multi-wavelength observations are encouraged. The MAGIC contact persons for these observations are R. Mirzoyan (razmik.mirzoyan@mpp.mpg.de) and M. Hayashida (mahaya@icrr.u-tokyo.ac.jp). 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.