1. Multiwavelength Variability and Correlation Studies of Mrk 421 During Historically Low X-ray and Y-ray Activity in 2015–2016
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Janeth Valverde Quispe, V. A. Acciari, S. Ansoldi, L. A. Antonelli, K. Asano, A. Babic, B. Banerjee, A. Baquero, U.BarresdeAlmeida, J. A. Barrio, J. Becerra Gonzalez, W. Bednarek, L. Bellizzi, E. Bernardini, M. Bernardos, A. Berti, J. Besenrieder, W. Bhattacharyya, C. Bigongiari, O. Blanch, G. Bonnoli, Z. Bosnjak, G. Busetto, R. Carosi, G. Ceribella, M. Cerruti, Y. Chai, A. Chilingarian, S. Cikota, S. M. Colak, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, G. D’Amico, V. D’Elia, P. Da Vela, F. Dazzi, A. De Angelis, B. De Lotto, M. Delfino, J. Delgado, C. Delgado Mendez, D. Depaoli, T. Di Girolamo, F. Di Pierro, L. Di Venere, E. Do Souto Espineira, D. Dominis Prester, A. Donini, M. Doro, V. Fallah Ramazani, A. Fattorini, G. Ferrara, L. Foffano, M. V. Fonseca, L. Font, C. Fruck, S. Fukami, R. J. Garcıa Lopez, M. Garczarczyk, S. Gasparyan, M. Gaug, N. Giglietto, F. Giordano, P. Gliwny, N. Godinovic, J. G. Green, D. Green, D. Hadasch, A. Hahn, L. Heckmann, J. Herrera, J. Hoang, D. Hrupec, M. Hutten, T. Inada, S. Inoue, K. Ishio, Y. Iwamura, J. Jormanainen, L. Jouvin, Y. Kajiwara, M. Karjalainen, D. Kerszberg, Y. Kobayashi, H. Kubo, J. Kushida, A. Lamastra, D. Lelas, F. Leone, E. Lindfors, S. Lombardi, F. Longo, M. Lopez, R. Lopez-Coto, A. Lopez-Oramas, S. Loporchio, B. Machado de Oliveira Fraga, C. Maggio, P. Majumdar, M. Makariev, M. Mallamaci, G. Maneva, M. Manganaro, L. Maraschi, M. Mariotti, M. Martınez, D. Mazin, S. Mender, S. Micanovic, D. Miceli, T. Miener, M. Minev, J. M. Miranda, R. Mirzoyan, E. Molina, A. Moralejo, D. Morcuende, V. Moreno, E. Moretti, P. Munar-Adrover, V. Neustroev, C. Nigro, K. Nilsson, D. Ninci, K. Nishijima, K. Noda, S. Nozaki, Y. Ohtani, T. Oka, J. Otero-Santos, M. Palatiello, D. Paneque, R. Paoletti, J. M. Paredes, L. Pavletic, P. P enil, C. Perennes, M. Persic, P. G . Prada Moroni, E. Prandini, C. Priyadarshi, I. Puljak, W. Rhode, M. Ribo, J. Rico, C. Righi, A. Rugliancich, L. Saha, N. Sahakyan, T. Saito, S. Sakurai, K. Satalecka, B. Schleicher, K. Schmidt, T. Schweizer, J. Sitarek, I. Snidaric, D. Sobczynska, A. Spolon, A. Stamerra, D. Strom, M. Strzys, Y. Suda, T. Suric, M. Takahashi, F. Tavecchio, P. Temnikov, T. Terzic, M. Teshima, N. Torres-Alba, L. Tosti, S. Truzzi, J. van Scherpenberg, G. Vanzo, M. Vazquez Acosta, S. Ventura, V. Verguilov, C. F. Vigorito, V. Vitale, I. Vovk, M. Will, D. Zaric, A. Arbet-Engels, D. Baack, M. Balbo, M. Beck, N. Biederbeck, A. Biland, T. Bretz, K. Bruegge, J. Buss, D. Dorner, D. Elsaesser, D. Hildebrand, R. Iotov, M. Klinger, K. Mannheim, D. Neise, A. Neronov, M. Noethe, A. Paravac, V. Sliusar, F. Theissen, R. Walter, J. Valverde, D. Horan, M. Giroletti, M. Perri, F. Verrecchia, C. Leto, A. C. Sadun, J. W. Moody, M. Joner, A. P. Marscher, S. G. Jorstad, A. Lahteenmaki, M. Tornikoski, V. Ramakrishnan, E. Jarvela, R. J. C. Vera, S. Righini, and A.Y.Lien
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Astronomy - Abstract
We report a characterization of the multiband flux variability and correlations of the nearby (z=0.031) blazar Markarian 421(Mrk 421) using data from Mets ̈ahovi, Swift, Fermi-LAT, MAGIC, FACT, and other collaborations and instruments from 2014November till 2016 June. Mrk 421 did not show any prominent flaring activity, but exhibited periods of historically low activity above 1 TeV (F>1TeV<1.7×10−12ph cm−2s−1) and in the 2–10 keV (X-ray) band (F2−10 keV<3.6×10−11erg cm−2s−1),during which the Swift-BAT data suggest an additional spectral component beyond the regular synchrotron emission. The highest flux variability occurs in X-rays and very high-energy (E>0.1 TeV)γ-rays, which, despite the low activity, show a significant positive correlation with no time lag. The HRkeV and HRTeV show the harder-when-brighter trend observed in many blazars, but the trend flattens at the highest fluxes, which suggests a change in the processes dominating the blazar variability. Enlarging our dataset with data from years 2007 to 2014, we measured a positive correlation between the optical and the GeV emission over a range of about 60 d centred at time lag zero, and a positive correlation between the optical/GeV and the radio emission over a range of about 60 d centred at a time lag of 43+9−6d. This observation is consistent with the radio-bright zone being located about 0.2 parsec downstream from the optical/GeV emission regions of the jet. The flux distributions are better described with a lognormal function in most of the energy bands probed, indicating that the variability in Mrk 421 is likely produced by a multiplicative process.
- Published
- 2020
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