Latest MAGIC discoveries pushing redshift boundaries in VHE Astrophysics

14th International Conference on Topics in Astroparticle and Underground Physics

物理学;天文学

Manganaro, M.^1,12 ; Becerra, J.^2,13 ; Nievas, M.^3 ; Sitarek, J.^4 ; Tavecchio, F.^5 ; Buson, S.^6 ; Dominis, D.^7 ; Domínguez, A.^3 ; Lindfors, E.^8 ; Mazin, D.^9 ; Moralejo, A.^10 ; Stamerra, A.^5 ; Vovk, Ie^11

Inst. de Astrofísica de Canarias, La Laguna

E-38200, Spain^1

NASA Goddard Space Flight Center, Greenbelt

MD

20771, United States^2

Universidad Complutense, Madrid

E-28040, Spain^3

University of Lodz, Lodz

PL-90236, Poland^4

INAF National Institute for Astrophysics, Rome

1-02236, Italy^5

Università di Padova, INFN, Padova

1-35131, Italy^6

Croatian MAGIC Consortium, Rudjer Boskovic Institute, University of Rijeka, University of Split, Zagreb

HR-10000, Croatia^7

Finnish MAGIC Consortium, Tuorla Observatory, University of Turku, Department of Physics, University of Oulu, Finland^8

Japanese MAGIC Consortium, ICRR, University of Tokyo, Department of Physics, Hakubi Center, Kyoto University, Tokai University, University of Tokushima, KEK, Japan

(10) IFAE, Campus UAB, Bellaterra

E-08193, Spain

(11) Max-Planck-Institut fur Physik, Munchen

D-80805, Germany

(12) Universidad de la Laguna, Dpto. Astrofísica, La Laguna, Tenerife

E-38206, Spain

(13) Department of Physics, University of Maryland, College Park

MD

20742, United States^9

关键词: Canary islands;    Extragalactic background light;    High energy gamma rays;    Imaging atmospheric Cherenkov telescopes;    Lightcurves;    Multiwavelength;    Optical bands;    Two sources;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/718/5/052022/pdf
DOI  :  10.1088/1742-6596/718/5/052022

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

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.