Bibcode
Manganaro, M.; Becerra, J.; Nievas, M.; Sitarek, J.; Tavecchio, F.; Buson, S.; Dominis, D.; Domínguez, A.; Lindfors, E.; Mazin, D.; Moralejo, A.; Stamerra, A.; Vovk, Ie; ">MAGIC, <author pre="for the; FERMI Collaboration
Referencia bibliográfica
Journal of Physics: Conference Series, Volume 718, Issue 5, article id. 052022 (2016).
Fecha de publicación:
5
2016
Número de citas
0
Número de citas referidas
0
Descripción
The search for detection of γ-rays from distant AGNs by Imaging
Atmospheric Cherenkov Telescopes (IACTs) is challenging at high
redshifts, not only because of lower flux due to the distance of the
source, but also due to the consequent absorption of γ-rays by the
extragalactic background light (EBL). Before the MAGIC discoveries
reported in this work, the farthest source ever detected in the VHE
domain was the blazar PKS 1424+240, at z > 0.6. MAGIC, a system of
two 17 m of diameter IACTs located in the Canary island of La Palma, has
been able to go beyond that limit and push the boundaries for VHE
detection to redshifts z ~ 1. The two sources detected and analyzed, the
blazar QSO B0218+357 and the FSRQ PKS 1441+25 are located at redshift z
= 0.944 and z = 0.939 respectively. QSO B0218+357 is also the first
gravitational lensed blazar ever detected in VHE. The activity,
triggered by Fermi-LAT in high energy γ-rays, was followed up by
other instruments, such as the KVA telescope in the optical band and the
Swift-XRT in X-rays. In the present work we show results on MAGIC
analysis on QSO B0218+357 and PKS 1441+25 together with multiwavelength
lightcurves. The collected dataset allowed us to test for the first time
the present generation of EBL models at such distances.