Very-high-energy γ-rays from the universe middle age: Detection of B0218+357 and PKS1441+25 with the MAGIC telescopes

Out of the ∼ 70 extragalactic sources known to emit in the Very High Energy band (VHE, E > 100GeV), only 5-6 are known to be Flat Spectrum Radio Quasars (FSRQs), and they are all found at intermediate or high redshifts. In this paper, we explore the conditions that trigger sub-TeV emission on this particular type of sources and we concentrate on the two most distant examples of this special population of blazars: the gravitationally lensed quasar B0218+357 and PKS 1441+25.