Speaker
Mr
Gabriele Cologna
(LSW Heidelberg)
Description
The high-frequency peaked BL Lac object 1ES$\,$0229+200 (z$\,$=$\,$0.14) was first detected in very high energy (VHE, E$\,$>$\,$100$\,$GeV) $\gamma$-rays by the H.E.S.S. (High Energy Stereoscopic System) collaboration in 2006. No variability was reported in the source in the initial study and its spectral characteristics have been used to derive constraints on the extragalactic background light (EBL, Aharonian et al. 2007) and on the intergalactic magnetic field (IGMF, e.g. Tavecchio et al. 2010, Dermer et al. 2011, Vovk et al. 2012). 1ES$\,$0229+200 has been observed with H.E.S.S. for $\sim$130$\,$hours from 2004 to 2013: we present here the full dataset analyzed with a more sensitive method. The results indicate that the source is not constant and displays flux variability on yearly and monthly timescales. No spectral change is detected. The existence of flux variability affects the derivation of constraints on both EBL and IGMF. The H.E.S.S. observations cover several simultaneous multi-frequency campaigns and we compare VHE variations with those reported in different bands.
| Registration number following "ICRC2015-I/" | 488 |
|---|---|
| Collaboration | H.E.S.S. |
Primary author
Mr
Gabriele Cologna
(LSW Heidelberg)
Co-authors
Dr
Alicja wierzcholska
(LSW Heidelberg)
Prof.
Stefan Wagner
(LSW Heidelberg)
