%0 Journal Article %T H.E.S.S. detection of very high-energy ¦Ã-ray emission from the quasar PKS 0736+017 %A A. A. Zdziarski %A A. Carosi %A A. Chen %A A. Djannati-Ata£¿ %A A. Dmytriiev %A A. Donath %A A. Fiasson %A A. Jardin-Blicq %A A. Lemi¨¨re %A A. M. Taylor %A A. M. W. Mitchell %A A. Marcowith %A A. Mares %A A. Priyana Noel %A A. Quirrenbach %A A. Reimer %A A. S. Seyffert %A A. Santangelo %A A. Schulz %A A. Sinha %A A. Specovius %A A. Wierzcholska %A A. Zech %A A. Ziegler %A B. Kh¨¦lifi %A B. Peyaud %A B. Rudak %A B. van Soelen %A C. Arcaro %A C. Armand %A C. Boisson %A C. Deil %A C. Hoischen %A C. Levy %A C. Mariaud %A C. Moore %A C. Perennes %A C. Romoli %A C. Stegmann %A C. Steppa %A C. Trichard %A C. Venter %A C. van Eldik %A C. van Rensburg %A D. A. Prokhorov %A D. A. Sanchez %A D. Berge %A D. Glawion %A D. Gottschall %A D. Horns %A D. Huber %A D. J. van der Walt %A D. Jankowsky %A D. Khangulyan %A D. Kostunin %A D. Malyshev %A D. Tiziani %A E. Leser %A E. Moulin %A E. O. Ang¨¹ner %A E. Ruiz-Velasco %A E. de O£¿a Wilhelmi %A F. Aharonian %A F. Ait Benkhali %A F. Brun %A F. Gat¨¦ %A F. Jankowsky %A F. Niederwanger %A F. Rieger %A F. Sch¨¹ssler %A F. Voisin %A G. Emery %A G. Fontaine %A G. Giavitto %A G. Heinzelmann %A G. Henri %A G. Hermann %A G. Lamanna %A G. Mart¨ª-Devesa %A G. Maurin %A G. P¨¹hlhofer %A G. Rowell %A G. Vasileiadis %A H. Abdalla %A H. Ashkar %A H. Iwasaki %A H. J. V£¿lk %A H. Ndiyavala %A H. Odaka %A H. Prokoph %A H. Schutte %A H. Sol %A H. Yoneda %A I. D. Davids %A I. Jung-Richardt %A I. Lypova %A I. Oya %A J. A. Hinton %A J. Bolmont %A J. Bregeon %A J. Devin %A J. Dyks %A J. F. Glicenstein %A J. Hahn %A J. King %A J. Lau %A J. Mackey %A J. Majumdar %A J. Muller %A J. Niemiec %A J. Veh %A J. Vink %A J. Zorn %A J.-P. Ernenwein %A J.-P. Lenain %A K. Bernl£¿hr %A K. Egberts %A K. Feijen %A K. Katarzy¨½ski %A K. Kosack %A K. Shiningayamwe %A L. Dirson %A L. Mohrmann %A L. Oakes %A L. O¡¯C. Drury %A L. Rinchiuso %A M. A. Kastendieck %J - %D 2020 %R 10.1051/0004-6361/201935906 %X Context. Flat-spectrum radio-quasars (FSRQs) are rarely detected at very high energies (E£¿¡Ý£¿100 GeV) due to their low-frequency-peaked spectral energy distributions. At present, only six FSRQs are known to emit very high-energy (VHE) photons, representing only 7% of the VHE extragalactic catalog, which is largely dominated by high-frequency-peaked BL Lacertae objects.Aims. Following the detection of MeV¨CGeV ¦Ã-ray flaring activity from the FSRQ PKS 0736+017 (z£¿=£¿0.189) with Fermi-LAT, the H.E.S.S. array of Cherenkov telescopes triggered target-of-opportunity (ToO) observations on February 18, 2015, with the goal of studying the ¦Ã-ray emission in the VHE band.Methods. H.E.S.S. ToO observations were carried out during the nights of February 18, 19, 21, and 24, 2015. Together with Fermi-LAT, the multi-wavelength coverage of the flare includes Swift observations in soft X-ray and optical-UV bands, and optical monitoring (photometry and spectro-polarimetry) by the Steward Observatory, and the ATOM, the KAIT, and the ASAS-SN telescopes.Results. VHE emission from PKS 0736+017 was detected with H.E.S.S. only during the night of February 19, 2015. Fermi-LAT data indicate the presence of a ¦Ã-ray flare, peaking at the time of the H.E.S.S. detection, with a flux doubling timescale of around six hours. The ¦Ã-ray flare was accompanied by at least a 1 mag brightening of the non-thermal optical continuum. No simultaneous observations at longer wavelengths are available for the night of the H.E.S.S. detection. The ¦Ã-ray observations with H.E.S.S. and Fermi-LAT are used to put constraints on the location of the ¦Ã-ray emitting region during the flare: it is constrained to be just outside the radius of the broad-line region rBLR with a bulk Lorentz factor ¦££¿£¿£¿20, or at the level of the radius of the dusty torus rtorus with ¦££¿£¿£¿60.Conclusions. PKS 0736+017 is the seventh FSRQ known to emit VHE photons, and at z£¿=£¿0.189 is the nearest so far. The location of the ¦Ã-ray emitting region during the flare can be tightly constrained thanks to opacity, variability, and collimation arguments %U https://www.aanda.org/articles/aa/full_html/2020/01/aa35906-19/aa35906-19.html