Multiwavelength Evidence for Quasi-periodic Modulation in the Gamma-ray Blazar PG 1553+113
Creators: name: The Fermi LAT Collaboration
name: Ackermann, M.
name: Ajello, M.
name: Albert, A.
name: Atwood, W. B.
name: Baldini, L.
name: Ballet, J.
name: Barbiellini, G.
name: Bastieri, D.
name: Gonzalez, J. Becerra
name: Bellazzini, R.
name: Bissaldi, E.
name: Blandford, R. D.
name: Bloom, E. D.
name: Bonino, R.
name: Bottacini, E.
name: Bregeon, J.
name: Bruel, P.
name: Buehler, R.
name: Buson, S.
name: Caliandro, G. A.
name: Cameron, R. A.
name: Caputo, R.
name: Caragiulo, M.
name: Caraveo, P. A.
name: Cavazzuti, E.
name: Cecchi, C.
name: Chekhtman, A.
name: Chiang, J.
name: Chiaro, G.
name: Ciprini, S.
name: Cohen-Tanugi, J.
name: Conrad, J.
name: Cutini, S.
name: D'Ammando, F.
name: De Angelis, A.
name: De Palma, F.
name: Desiante, R.
name: Di Venere, L.
name: Dominguez, A.
name: Drell, P. S.
name: Favuzzi, C.
name: Fegan, S. J.
name: Ferrara, E. C.
name: Focke, W. B.
name: Fuhrmann, L.
name: Fukazawa, Y.
name: Fusco, P.
name: Gargano, F.
name: Gasparrini, D.
name: Giglietto, N.
name: Giommi, P.
name: Giordano, F.
name: Giroletti, M.
name: Godfrey, G.
name: Green, D.
name: Grenier, I. A.
name: Grove, J. E.
name: Guiriec, S.
name: Harding, A. K.
name: Hays, E.
name: Hewitt, J. W.
name: Hill, A. B.
name: Horan, D.
name: Jogler, T.
name: Johannesson, G.
name: Johnson, A. S.
name: Kamae, T.
name: Kuss, M.
name: Larsson, S.
name: Latronico, L.
name: Li, J.
name: Li, L.
name: Longo, F.
name: Loparco, F.
name: Lott, B.
name: Lovellette, M. N.
name: Lubrano, P.
name: Magill, J.
name: Maldera, S.
name: Manfreda, A.
name: Max-Moerbeck, W.
name: Mayer, M.
name: Mazziotta, M. N.
name: Mcenery, J. E.
name: Michelson, P. F.
name: Mizuno, T.
name: Monzani, M. E.
name: Morselli, A.
name: Moskalenko, I. V.
name: Murgia, S.
name: Nuss, E.
name: Ohno, M.
name: Ohsugi, T.
name: Ojha, R.
name: Omodei, N.
name: Orlando, E.
name: Ormes, J. F.
name: Paneque, D.
name: Pearson, T. J.
name: Perkins, J. S.
name: Perri, M.
name: Pesce-Rollins, M.
name: Petrosian, V.
name: Piron, F.
name: Pivato, G.
name: Porter, T. A.
name: Raino', S.
name: Rando, R.
name: Razzano, M.
name: Readhead, A.
name: Reimer, A.
name: Reimer, O.
name: Schulz, A.
name: Sgro', C.
name: Siskind, E. J.
name: Spada, F.
name: Spandre, G.
name: Spinelli, P.
name: Suson, D. J.
name: Takahashi, H.
name: Thayer, J. B.
name: Thompson, D. J.
name: Tibaldo, L.
name: Torres, D. F.
name: Tosti, G.
name: Troja, E.
name: Uchiyama, Y.
name: Vianello, G.
name: Wood, K. S.
name: Wood, M.
name: Zimmer, S.
name: Berdyugin, A.
name: Corbet, R. H. D.
name: Hovatta, T.
name: Lindfors, E.
name: Nilsson, K.
name: Reinthal, R.
name: Sillanpaa, A.
name: Stamerra, A.
name: Takalo, L. O.
name: Valtonen, M. J.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report for the first time a gamma-ray and multi-wavelength nearly-periodic oscillation in an active galactic nucleus. Using the Fermi Large Area Telescope (LAT) we have discovered an apparent quasi-periodicity in the gamma-ray flux (E &gt;100 MeV) from the GeV/TeV BL Lac object PG 1553+113. The marginal significance of the 2.18 +/-0.08 year-period gamma-ray cycle is strengthened by correlated oscillations observed in radio and optical fluxes, through data collected in the OVRO, Tuorla, KAIT, and CSS monitoring programs and Swift UVOT. The optical cycle appearing in ~10 years of data has a similar period, while the 15 GHz oscillation is less regular than seen in the other bands. Further long-term multi-wavelength monitoring of this blazar may discriminate among the possible explanations for this quasi-periodicity.
description: 8 pages, 5 figures. Accepted to The Astrophysical Journal Letters. Corresponding authors: S. Ciprini (ASDC/INFN), S. Cutini (ASDC/INFN), S. Larsson (Stockholm Univ/KTH), A. Stamerra (INAF/SNS), D. J. Thompson (NASA GSFC)