Title: | Investigation of the correlation patterns and the Compton dominance variability of Mrk 421 in 2017 |
Authors: | MAGIC Collaboration Acciari, V. A. Ansoldi, S. ANTONELLI, Lucio Angelo Arbet Engels, A. Artero, M. Asano, K. Babić, A. Baquero, A. Barres de Almeida, U. Barrio, J. A. Majumdar, P. Makariev, M. Mallamaci, M. Maneva, G. Manganaro, M. Maraschi, L. Mariotti, M. Martínez, M. Mazin, D. Menchiari, S. Batković, I. Mender, S. Mićanović, S. Miceli, D. Miener, T. Minev, M. Miranda, J. M. Mirzoyan, R. Molina, E. Moralejo, A. Morcuende, D. Becerra González, J. Moreno, V. Moretti, E. Neustroev, V. Nigro, C. Nilsson, K. Nishijima, K. Noda, K. Nozaki, S. Ohtani, Y. Oka, T. Bednarek, W. Otero-Santos, J. PAIANO, Simona Palatiello, M. Paneque, D. Paoletti, R. Paredes, J. M. Pavletić, L. Peñil, P. Perennes, C. PERSIC, Massimo Bellizzi, L. Prada Moroni, P. G. PRANDINI, ELISA Priyadarshi, C. Puljak, I. Ribó, M. Rico, J. RIGHI, Chiara Rugliancich, A. Saha, L. Sahakyan, N. Bernardini, E. Saito, T. Sakurai, S. Satalecka, K. SATURNI, Francesco Gabriele Schmidt, K. Schweizer, T. Sitarek, J. Šnidarić, I. Sobczynska, D. Spolon, A. Bernardos, M. STAMERRA, Antonio Strom, D. Strzys, M. Suda, Y. Surić, T. Takahashi, M. TAVECCHIO, Fabrizio Temnikov, P. Terzić, T. Teshima, M. Berti, A. Tosti, L. Truzzi, S. Tutone, A. Ubach, S. van Scherpenberg, J. Vanzo, G. Vazquez Acosta, M. Ventura, S. Verguilov, V. Vigorito, C. F. Besenrieder, J. Vitale, V. Vovk, I. Will, M. Wunderlich, C. Zarić, D. FACT Collaboration Baack, D. Balbo, M. Biederbeck, N. Biland, A. Bhattacharyya, W. Bretz, T. Buss, J. Dorner, D. Eisenberger, L. Elsaesser, D. Hildebrand, D. Iotov, R. Mannheim, K. Neise, D. Noethe, M. BIGONGIARI, Ciro Paravac, A. Rhode, W. Schleicher, B. Sliusar, V. Walter, R. D'AMMANDO, Filippo Horan, D. Lien, A. Y. Baloković, M. Madejski, G. M. Blanch, O. PERRI, Matteo VERRECCHIA, Francesco Leto, C. Lähteenmäki, A. Tornikoski, M. Ramakrishnan, V. Järvelä, E. Vera, R. J. C. Chamani, W. VILLATA, Massimo Bošnjak, Ž. RAITERI, Claudia Maria Gupta, A. C. Pandey, A. Fuentes, A. Agudo, I. Casadio, C. Semkov, E. Ibryamov, S. Marchini, A. Bachev, R. Busetto, G. Strigachev, A. Ovcharov, E. Bozhilov, V. Valcheva, A. Zaharieva, E. Damljanovic, G. Vince, O. Larionov, V. M. Borman, G. A. Grishina, T. S. Carosi, R. Hagen-Thorn, V. A. Kopatskaya, E. N. Larionova, E. G. Larionova, L. V. Morozova, D. A. Nikiforova, A. A. Savchenko, S. S. Troitskiy, I. S. Troitskaya, Y. V. Vasilyev, A. A. Ceribella, G. Merkulova, O. A. Chen, W. P. Samal, M. Lin, H. C. Moody, J. W. Sadun, A. C. Jorstad, S. G. Marscher, A. P. Weaver, Z. R. Feige, M. Cerruti, M. Kania, J. Kopp, M. Kunkel, L. Reinhart, D. Scherbantin, A. Schneider, L. Lorey, C. Acosta-Pulido, J. A. CARNERERO MARTIN, Maria Isabel Carosati, D. Chai, Y. Kurtanidze, S. O. Kurtanidze, O. M. Nikolashvili, M. G. Chigladze, R. A. Ivanidze, R. Z. Kimeridze, G. N. Sigua, L. A. Joner, M. D. Spencer, M. GIROLETTI, Marcello Chilingarian, A. MARCHILI, Nicola RIGHINI, Simona Rizzi, N. BONNOLI, Giacomo Cikota, S. Colak, S. M. Colombo, E. Contreras, J. L. Cortina, J. COVINO, Stefano D'Amico, G. D'Elia, V. da Vela, P. DAZZI, Francesco de Angelis, A. de Lotto, B. Delfino, M. Delgado, J. Delgado Mendez, C. Depaoli, D. di Pierro, F. di Venere, L. Do Souto Espiñeira, E. Dominis Prester, D. Donini, A. Doro, M. Fallah Ramazani, V. Fattorini, A. Ferrara, G. Fonseca, M. V. Font, L. Fruck, C. Fukami, S. García López, R. J. Garczarczyk, M. Gasparyan, S. Gaug, M. Giglietto, N. Giordano, F. Gliwny, P. Godinović, N. GREEN, JARRED GERSHON Green, D. Hadasch, D. Hahn, A. Heckmann, L. Herrera, J. Hoang, J. Hrupec, D. Hütten, M. Inada, T. Inoue, S. Ishio, K. Iwamura, Y. Jiménez, I. Jormanainen, J. Jouvin, L. Kajiwara, Y. Karjalainen, M. Kerszberg, D. Kobayashi, Y. Kubo, H. Kushida, J. LAMASTRA, Alessandra Lelas, D. LEONE, Francesco Lindfors, E. LOMBARDI, Saverio Longo, F. López-Coto, R. López-Moya, M. López-Oramas, A. Loporchio, S. Machado de Oliveira Fraga, B. Maggio, C. |
Issue Date: | 2021 |
Journal: | ASTRONOMY & ASTROPHYSICS |
Number: | 655 |
First Page: | A89 |
Abstract: | <BR /> Aims: We present a detailed characterisation and theoretical interpretation of the broadband emission of the paradigmatic TeV blazar Mrk 421, with a special focus on the multi-band flux correlations. <BR /> Methods: The dataset has been collected through an extensive multi-wavelength campaign organised between 2016 December and 2017 June. The instruments involved are MAGIC, FACT, Fermi-LAT, Swift, GASP-WEBT, OVRO, Medicina, and Metsähovi. Additionally, four deep exposures (several hours long) with simultaneous MAGIC and NuSTAR observations allowed a precise measurement of the falling segments of the two spectral components. <BR /> Results: The very-high-energy (VHE; E > 100 GeV) gamma rays and X-rays are positively correlated at zero time lag, but the strength and characteristics of the correlation change substantially across the various energy bands probed. The VHE versus X-ray fluxes follow different patterns, partly due to substantial changes in the Compton dominance for a few days without a simultaneous increase in the X-ray flux (i.e., orphan gamma-ray activity). Studying the broadband spectral energy distribution (SED) during the days including NuSTAR observations, we show that these changes can be explained within a one-zone leptonic model with a blob that increases its size over time. The peak frequency of the synchrotron bump varies by two orders of magnitude throughout the campaign. Our multi-band correlation study also hints at an anti-correlation between UV-optical and X-ray at a significance higher than 3σ. A VHE flare observed on MJD 57788 (2017 February 4) shows gamma-ray variability on multi-hour timescales, with a factor ten increase in the TeV flux but only a moderate increase in the keV flux. The related broadband SED is better described by a two-zone leptonic scenario rather than by a one-zone scenario. We find that the flare can be produced by the appearance of a compact second blob populated by high energetic electrons spanning a narrow range of Lorentz factors, from γ'<SUB>min</SUB>=2×10<SUP>4</SUP> to γ'<SUB>max</SUB>=6×10<SUP>5</SUP>. <P />Light curves and spectral energy distributions data are only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr/">cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/655/A89">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/655/A89</A> |
URI: | http://hdl.handle.net/20.500.12386/36223 |
URL: | https://www.aanda.org/articles/aa/full_html/2021/11/aa41004-21/aa41004-21.html |
ISSN: | 0004-6361 |
DOI: | 10.1051/0004-6361/202141004 |
Bibcode ADS: | 2021A&A...655A..89M |
Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista
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