VHE $γ$-ray discovery and multi-wavelength study of the blazar 1ES 2322-409
Creators: name: Collaboration, H. E. S. S.
name: :
name: Abdalla, H.
name: Aharonian, F.
name: Benkhali, F. Ait
name: Angüner, E. O.
name: Arakawa, M.
name: Arcaro, C.
name: Armand, C.
name: Arrieta, M.
name: Backes, M.
name: Barnard, M.
name: Becherini, Y.
name: Tjus, J. Becker
name: Berge, D.
name: Bernhard, S.
name: Bernlöhr, K.
name: Blackwell, R.
name: Böttcher, M.
name: Boisson, C.
name: Bolmont, J.
name: Bonnefoy, S.
name: Bordas, P.
name: Bregeon, J.
name: Brun, F.
name: Brun, P.
name: Bryan, M.
name: Büchele, M.
name: Bulik, T.
name: Bylund, T.
name: Capasso, M.
name: Caroff, S.
name: Carosi, A.
name: Casanova, S.
name: Cerruti, M.
name: Chakraborty, N.
name: Chandra, S.
name: Chaves, R. C. G.
name: Chen, A.
name: Colafrancesco, S.
name: Condon, B.
name: Davids, I. D.
name: Deil, C.
name: Devin, J.
name: deWilt, P.
name: Dirson, L.
name: Djannati-Ataï, A.
name: Dmytriiev, A.
name: Donath, A.
name: Drury, L. O'C.
name: Dyks, J.
name: Egberts, K.
name: Emery, G.
name: Ernenwein, J. -P.
name: Eschbach, S.
name: Fegan, S.
name: Fiasson, A.
name: Fontaine, G.
name: Funk, S.
name: Füßling, M.
name: Gabici, S.
name: Gallant, Y. A.
name: Garrigoux, T.
name: Gaté, F.
name: Giavitto, G.
name: Glawion, D.
name: Glicenstein, J. F.
name: Gottschall, D.
name: Grondin, M. -H.
name: Hahn, J.
name: Haupt, M.
name: Heinzelmann, G.
name: Henri, G.
name: Hermann, G.
name: Hinton, J. A.
name: Hofmann, W.
name: Hoischen, C.
name: Holch, T. L.
name: Holler, M.
name: Horns, D.
name: Huber, D.
name: Iwasaki, H.
name: Jacholkowska, A.
name: Jamrozy, M.
name: Jankowsky, D.
name: Jankowsky, F.
name: Jouvin, L.
name: Jung-Richardt, I.
name: Kastendieck, M. A.
name: Katarzyński, K.
name: Katsuragawa, M.
name: Katz, U.
name: Kerszberg, D.
name: Khangulyan, D.
name: Khélifi, B.
name: King, J.
name: Klepser, S.
name: Kluźniak, W.
name: Komin, Nu.
name: Kosack, K.
name: Krakau, S.
name: Kraus, M.
name: Krüger, P. P.
name: Lamanna, G.
name: Lau, J.
name: Lefaucheur, J.
name: Lemière, A.
name: Lemoine-Goumard, M.
name: Lenain, J. -P.
name: Leser, E.
name: Lohse, T.
name: Lorentz, M.
name: López-Coto, R.
name: Lypova, I.
name: Malyshev, D.
name: Marandon, V.
name: Marcowith, A.
name: Mariaud, C.
name: Martí-Devesa, G. Guillem
name: Marx, R.
name: Maurin, G.
name: Meintjes, P. J.
name: Mitchell, A. M. W.
name: Moderski, R.
name: Mohamed, M.
name: Mohrmann, L.
name: Moulin, E.
name: Murach, T.
name: Nakashima, S.
name: de Naurois, M.
name: Ndiyavala, H.
name: Niederwanger, F.
name: Niemiec, J.
name: Oakes, L.
name: O'Brien, P.
name: Odaka, H.
name: Ohm, S.
name: Ostrowski, M.
name: Oya, I.
name: Padovani, M.
name: Panter, M.
name: Parsons, R. D.
name: Perennes, C.
name: Petrucci, P. -O.
name: Peyaud, B.
name: Piel, Q.
name: Pita, S.
name: Poireau, V.
name: Noel, A. Priyana
name: Prokhorov, D. A.
name: Prokoph, H.
name: Pühlhofer, G.
name: Punch, M.
name: Quirrenbach, A.
name: Raab, S.
name: Rauth, R.
name: Reimer, A.
name: Reimer, O.
name: Renaud, M.
name: Rieger, F.
name: Rinchiuso, L.
name: Romoli, C.
name: Rowell, G.
name: Rudak, B.
name: Ruiz-Velasco, E.
name: Sahakian, V.
name: Saito, S.
name: Sanchez, D. A.
name: Santangelo, A.
name: Sasaki, M.
name: Schlickeiser, R.
name: Schüssler, F.
name: Schulz, A.
name: Schwanke, U.
name: Schwemmer, S.
name: Seglar-Arroyo, M.
name: Senniappan, M.
name: Seyffert, A. S.
name: Shafi, N.
name: Shilon, I.
name: Shiningayamwe, K.
name: Simoni, R.
name: Sinha, A.
name: Sol, H.
name: Spanier, F.
name: Specovius, A.
name: Spir-Jacob, M.
name: Stawarz, Ł.
name: Steenkamp, R.
name: Stegmann, C.
name: Steppa, C.
name: Sushch, I.
name: Takahashi, T.
name: Tavernet, J. -P.
name: Tavernier, T.
name: Taylor, A. M.
name: Terrier, R.
name: Tibaldo, L.
name: Tiziani, D.
name: Tluczykont, M.
name: Trichard, C.
name: Tsirou, M.
name: Tsuji, N.
name: Tuffs, R.
name: Uchiyama, Y.
name: van der Walt, D. J.
name: van Eldik, C.
name: van Rensburg, C.
name: van Soelen, B.
name: Vasileiadis, G.
name: Veh, J.
name: Venter, C.
name: Viana, A.
name: Vincent, P.
name: Vink, J.
name: Voisin, F.
name: Völk, H. J.
name: Vuillaume, T.
name: Wadiasingh, Z.
name: Wagner, S. J.
name: Wagner, P.
name: Wagner, R. M.
name: White, R.
name: Wierzcholska, A.
name: Wörnlein, A.
name: Yang, R.
name: Zaborov, D.
name: Zacharias, M.
name: Zanin, R.
name: Zdziarski, A. A.
name: Zech, A.
name: Zefi, F.
name: Ziegler, A.
name: Zorn, J.
name: Żywucka, N.
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: A hotspot at a position compatible with the BL Lac object 1ES 2322-409 was serendipitously detected with H.E.S.S. during observations performed in 2004 and 2006 on the blazar PKS 2316-423. Additional data on 1ES 2322-409 were taken in 2011 and 2012, leading to a total live-time of 22.3h. Point-like very-high-energy (VHE; E&gt;100GeV) $γ$-ray emission is detected from a source centred on the 1ES 2322-409 position, with an excess of 116.7 events at a significance of 6.0$σ$. The average VHE $γ$-ray spectrum is well described with a power law with a photon index $Γ=3.40\pm0.66_{\text{stat}}\pm0.20_{\text{sys}}$ and an integral flux $Φ(E&gt;200GeV) = (3.11\pm0.71_{\rm stat}\pm0.62_{\rm sys})\times10^{-12} cm^{-2} s^{-1}$, which corresponds to 1.1$\%$ of the Crab nebula flux above 200 GeV. Multi-wavelength data obtained with Fermi LAT, Swift XRT and UVOT, RXTE PCA, ATOM, and additional data from WISE, GROND and Catalina, are also used to characterise the broad-band non-thermal emission of 1ES 2322-409. The multi-wavelength behaviour indicates day-scale variability. Swift UVOT and XRT data show strong variability at longer scales. A spectral energy distribution (SED) is built from contemporaneous observations obtained around a high state identified in Swift data. A modelling of the SED is performed with a stationary homogeneous one-zone synchrotron-self-Compton (SSC) leptonic model. The redshift of the source being unknown, two plausible values were tested for the modelling. A systematic scan of the model parameters space is performed, resulting in a well-constrained combination of values providing a good description of the broad-band behaviour of 1ES 2322-409.
description: Accepted for publication in MNRAS. 13 pages, 8 figures