A4 Refereed article in a conference publication
The unprecedented VHE γ-ray outburst of PKS 1510-089 in May 2016
Authors: Terzic, Tomislav; Zacharias, Michael; Sitarek, Julian; Meyer, Manuel; Prester, Dijana Dominis; Jankowsky, Felix; Lindfors, Elina; Mohamed, Mahmoud; Sanchez, David
Editors: Battistelli, ES; Jantzen, RT; Ruffini, R
Conference name: Marcell Grossmann Meeting
Publisher: WORLD SCIENTIFIC PUBL CO PTE LTD
Publishing place: SINGAPORE
Publication year: 2022
Book title : Proceeding of the fifteenth Marcel Grossmann Meeting on General Relativity
Journal acronym: Marcel Grossmann Mee
Series title: Marcel Grossmann Meetings
First page : 1681
Last page: 1686
Number of pages: 6
ISBN: 978-981-125-824-4
eISBN: 978-981-125-825-1
DOI: https://doi.org/10.1142/9789811258251_0249
Publication's open availability at the time of reporting: Open Access
Publication channel's open availability : No Open Access publication channel
Web address : https://www.worldscientific.com/doi/10.1142/9789811258251_0249
PKS 1510-089 (z = 0.361), one of only a handful of flat spectrum radio quasars detected in the very high energy (VHE, E > 100 GeV) gamma-rays, is known for its flux variability and complex multiwavelength behaviour. VHE observations by H.E.S. S. and MAGIC in May 2016 detected an unprecedented flare, both in intensity and in the shortness of its variability timescale. The flare lasted less than 48 hours, during which time the flux reached about 80 per cent of the Crab Nebula flux above 200 GeV. In addition, the intranight variability of this source was detected for the first time. Simultaneous observations in high energy (HE, E > 100MeV) gamma-rays performed with Fermi-LAT and optical R-band performed with ATOM show behaviour not consistent with simple simultaneous brightening in all bands. While a significant hardening of the spectrum is visible in HE, the flux increased only moderately. A simultaneous rise in daily-averaged optical flux was seen in the R-band. However, the intranight R-band flux evolution shows two prominent peaks, while only one is visible in the VHE range. These intriguing features of the flare will be presented in detail. We will also discuss possible explanations for the observed emission.
Funding information in the publication:
H.E.S.S. gratefully acknowledges financial support from the agencies and organisations listed at https://www.mpi hd.mpg.de/hfm/HESS/pages/publications/auxiliary/HESS-Acknowledgements-2019.html. MAGIC gratefully acknowledges financial support from the agencies and organisations listed at https://magic.mpp.mpg.de/ack_201805/
