Investigation of the correlation patterns and the Compton dominance variability of Mrk 421 in 2017
Journal
Date Issued
2021
Author(s)
MAGIC Collaboration
•
Acciari, V. A.
•
Ansoldi, S.
•
•
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.
•
•
Palatiello, M.
•
Paneque, D.
•
Paoletti, R.
•
Paredes, J. M.
•
Pavletić, L.
•
Peñil, P.
•
Perennes, C.
•
•
Bellizzi, L.
•
Prada Moroni, P. G.
•
•
Priyadarshi, C.
•
Puljak, I.
•
Ribó, M.
•
Rico, J.
•
•
Rugliancich, A.
•
Saha, L.
•
Sahakyan, N.
•
Bernardini, E.
•
Saito, T.
•
Sakurai, S.
•
Satalecka, K.
•
•
Schmidt, K.
•
Schweizer, T.
•
Sitarek, J.
•
Šnidarić, I.
•
Sobczynska, D.
•
Spolon, A.
•
Bernardos, M.
•
•
Strom, D.
•
Strzys, M.
•
Suda, Y.
•
Surić, T.
•
Takahashi, M.
•
•
Temnikov, P.
•
Terzić, T.
•
Teshima, M.
•
Berti, A.
•
Tosti, L.
•
Truzzi, S.
•
•
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.
•
•
Paravac, A.
•
Rhode, W.
•
Schleicher, B.
•
Sliusar, V.
•
Walter, R.
•
•
Horan, D.
•
Lien, A. Y.
•
Baloković, M.
•
Madejski, G. M.
•
Blanch, O.
•
•
•
Leto, C.
•
Lähteenmäki, A.
•
Tornikoski, M.
•
Ramakrishnan, V.
•
Järvelä, E.
•
Vera, R. J. C.
•
Chamani, W.
•
•
Bošnjak, Ž.
•
•
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.
•
•
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.
•
•
Chilingarian, A.
•
•
•
Rizzi, N.
•
•
Cikota, S.
•
Colak, S. M.
•
Colombo, E.
•
Contreras, J. L.
•
Cortina, J.
•
•
D'Amico, G.
•
D'Elia, V.
•
da Vela, P.
•
•
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, 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.
•
•
Lelas, D.
•
•
Lindfors, E.
•
•
Longo, F.
•
López-Coto, R.
•
López-Moya, M.
•
López-Oramas, A.
•
Loporchio, S.
•
Machado de Oliveira Fraga, B.
•
Maggio, C.
Abstract
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.
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.
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'min=2×104 to γ'max=6×105.
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.
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.
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'min=2×104 to γ'max=6×105.
Light curves and spectral energy distributions data are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/655/A89
Volume
655
Start page
A89
Issn Identifier
0004-6361
Ads BibCode
2021A&A...655A..89M
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
aa41004-21.pdf
Size
1.56 MB
Format
Adobe PDF
Checksum (MD5)
78ac5b3194b42b0066be9aa4ff35cb66