TY - JOUR
T1 - Unveiling the complex correlation patterns in Mrk 421
AU - the MAGIC
AU - FACT
AU - Fermi-LAT Collaborations and multi-wavelength collaborators
AU - Arbet-Engels, A.
AU - Paneque, D.
AU - Heckmann, L.
AU - Acciari, V. A.
AU - Ansoldi, S.
AU - Antonelli, L. A.
AU - Artero, M.
AU - Asano, K.
AU - Baack, D.
AU - Babić, A.
AU - Baquero, A.
AU - Barres de Almeida, U.
AU - Barrio, J. A.
AU - Batković, I.
AU - Becerra González, J.
AU - Bednarek, W.
AU - Bellizzi, L.
AU - Bernardini, E.
AU - Bernardos, M.
AU - Berti, A.
AU - Besenrieder, J.
AU - Bhattacharyya, W.
AU - Bigongiari, C.
AU - Biland, A.
AU - Blanch, O.
AU - Bökenkamp, H.
AU - Bonnoli, G.
AU - Bošnjak,
AU - Busetto, G.
AU - Carosi, R.
AU - Ceribella, G.
AU - Cerruti, M.
AU - Chai, Y.
AU - Chilingarian, A.
AU - Cikota, S.
AU - Colak, S. M.
AU - Colombo, E.
AU - Contreras, J. L.
AU - Cortina, J.
AU - Covino, S.
AU - D'Amico, G.
AU - D'Elia, V.
AU - Da Vela, P.
AU - Dazzi, F.
AU - De Angelis, A.
AU - De Lotto, B.
AU - Delfino, M.
AU - Delgado, J.
AU - Delgado Mendez, C.
AU - Chen, W. P.
N1 - Publisher Copyright:
© Copyright owned by the author(s) under the terms of the Creative Commons.
PY - 2022/3/18
Y1 - 2022/3/18
N2 - The blazar Mrk 421 (redshift z = 0.031) is one of the brightest and closest BL Lac type objects, making it an ideal target to probe blazar physics. We report on an extensive multi-wavelength observing campaign in 2017, during which the intra-band correlation patterns show some disparity and complex behaviours. Observations from several instruments are used to achieve an optimal temporal coverage from radio to TeV energies. In particular, four multi-hour NuSTAR observations organised simultaneously with MAGIC allow to obtain a precise measurement of the falling segments of the two spectral components. A detailed investigation of the very-high-energy (VHE; > 100 GeV) versus X-ray flux correlation is performed, by binning the data into several sub-energy bands. A positively correlated variability is observed, but the correlation characteristics change substantially across the various bands probed. Furthermore, during the simultaneous MAGIC and NuSTAR observations a clear change of the Compton dominance is detected without a simultaneous change in the synchrotron regime, indicating "orphan gamma-ray activity". We also investigate an intriguing bright flare at VHE without a substantial flux increase in the X-rays. Within a leptonic scenario, this behaviour is best explained by the appearance of a second population of highly-energetic electrons spanning a narrow range of energies. Finally, our multi-wavelength correlation study also reveals an anti-correlation between the UV/optical and X-ray bands at a significance level above 3σ.
AB - The blazar Mrk 421 (redshift z = 0.031) is one of the brightest and closest BL Lac type objects, making it an ideal target to probe blazar physics. We report on an extensive multi-wavelength observing campaign in 2017, during which the intra-band correlation patterns show some disparity and complex behaviours. Observations from several instruments are used to achieve an optimal temporal coverage from radio to TeV energies. In particular, four multi-hour NuSTAR observations organised simultaneously with MAGIC allow to obtain a precise measurement of the falling segments of the two spectral components. A detailed investigation of the very-high-energy (VHE; > 100 GeV) versus X-ray flux correlation is performed, by binning the data into several sub-energy bands. A positively correlated variability is observed, but the correlation characteristics change substantially across the various bands probed. Furthermore, during the simultaneous MAGIC and NuSTAR observations a clear change of the Compton dominance is detected without a simultaneous change in the synchrotron regime, indicating "orphan gamma-ray activity". We also investigate an intriguing bright flare at VHE without a substantial flux increase in the X-rays. Within a leptonic scenario, this behaviour is best explained by the appearance of a second population of highly-energetic electrons spanning a narrow range of energies. Finally, our multi-wavelength correlation study also reveals an anti-correlation between the UV/optical and X-ray bands at a significance level above 3σ.
UR - http://www.scopus.com/inward/record.url?scp=85145439093&partnerID=8YFLogxK
M3 - 會議論文
AN - SCOPUS:85145439093
SN - 1824-8039
VL - 395
JO - Proceedings of Science
JF - Proceedings of Science
M1 - 834
T2 - 37th International Cosmic Ray Conference, ICRC 2021
Y2 - 12 July 2021 through 23 July 2021
ER -