2025-03-21 マックス・プランク研究所（MPG）
＜関連情報＞
- https://www.mpg.de/24603834/news-from-mpi
- https://www.aanda.org/articles/aa/full_html/2025/03/aa52785-24/aa52785-24.html
- https://www.aanda.org/articles/aa/full_html/2024/05/aa48709-23/aa48709-23.html
- https://www.aanda.org/articles/aa/full_html/2024/04/aa47988-23/aa47988-23.html
X線偏光とVHEガンマ線を持つ高シンクロトロンピークブレイザーの最初のフレア活動からの洞察 Insights from the first flaring activity of a high synchrotron peaked blazar with X-ray polarization and VHE gamma rays
MAGIC Collaboration
K. Abe, S. Abe, J. Abhir, A. Abhishek, V. A. Acciari, A. Aguasca-Cabot, I. Agudo, T. Aniello, S. Ansoldi,, L. A. Antonelli, A. Arbet Engels⋆, C. Arcaro, K. Asano, A. Babić, U. Barres de Almeida, J. A. Barrio, L. Barrios-Jiménez, I. Batković, J. Baxter, J. Becerra González, W. Bednarek, E. Bernardini, J. Bernete, A. Berti, J. Besenrieder, C. Bigongiari, A. Biland, O. Blanch, G. Bonnoli, Ž Bošnjak, E. Bronzini, I. Burelli, A. Campoy-Ordaz, A. Carosi, R. Carosi, M. Carretero-Castrillo, A. J. Castro-Tirado, D. Cerasole, G. Ceribella, Y. Chai, A. Chilingarian, A. Cifuentes, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, F. D’Ammando, G. D’Amico, P. Da Vela, F. Dazzi, A. De Angelis, B. De Lotto, R. de Menezes, M. Delfino,, J. Delgado,, C. Delgado Mendez, F. Di Pierro, R. Di Tria, L. Di Venere, A. Dinesh, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, L. Eisenberger, D. Elsaesser,, J. Escudero, L. Fariña, L. Foffano, L. Font, S. Fröse, Y. Fukazawa,,, R. J. García López, M. Garczarczyk, S. Gasparyan, M. Gaug, J. G. Giesbrecht Paiva, N. Giglietto, F. Giordano, P. Gliwny, N. Godinović, T. Gradetzke, R. Grau, D. Green, J. G. Green, P. Günther, D. Hadasch, A. Hahn, T. Hassan, L. Heckmann,⋆, J. Herrera Llorente, D. Hrupec, R. Imazawa, D. Israyelyan, T. Itokawa, I. Jiménez Martínez, J. Jiménez Quiles, J. Jormanainen, S. Kankkunen, T. Kayanoki, D. Kerszberg, M. Khachatryan, G. W. Kluge,, Y. Kobayashi, J. Konrad, P. M. Kouch, H. Kubo, J. Kushida, M. Láinez, A. Lamastra, E. Lindfors, S. Lombardi, F. Longo,, R. López-Coto, M. López-Moya, A. López-Oramas, S. Loporchio, A. Lorini, E. Lyard, P. Majumdar, M. Makariev, G. Maneva, M. Manganaro, S. Mangano, K. Mannheim,, M. Mariotti, M. Martínez, P. Maruševec, A. Mas-Aguilar, D. Mazin,, S. Menchiari, S. Mender, D. Miceli, J. M. Miranda, R. Mirzoyan, M. Molero González, E. Molina, H. A. Mondal, A. Moralejo, T. Nakamori, C. Nanci, V. Neustroev, L. Nickel, M. Nievas Rosillo, C. Nigro, L. Nikolić, K. Nilsson, K. Nishijima, T. Njoh Ekoume, K. Noda, S. Nozaki, A. Okumura, S. Paiano, D. Paneque⋆, R. Paoletti, J. M. Paredes, M. Peresano, M. Persic,, M. Pihet, G. Pirola, F. Podobnik, P. G. Prada Moroni, E. Prandini, G. Principe, W. Rhode, M. Ribó, J. Rico, C. Righi, N. Sahakyan, T. Saito, F. G. Saturni, F. Schmuckermaier, J. L. Schubert, A. Sciaccaluga, G. Silvestri, J. Sitarek, V. Sliusar, D. Sobczynska, A. Stamerra, J. Strišković, D. Strom, M. Strzys, Y. Suda, H. Tajima, M. Takahashi, R. Takeishi, P. Temnikov, K. Terauchi, T. Terzić, M. Teshima,, S. Truzzi, A. Tutone, S. Ubach, J. van Scherpenberg, S. Ventura, G. Verna, I. Viale, A. Vigliano, C. F. Vigorito, V. Vitale, I. Vovk, R. Walter, F. Wersig, M. Will, T. Yamamoto and P. K. H. Yeung
Other groups and collaborations
I. Liodakis,, R. Middei,, S. Kiehlmann, L. D. Gesu, D. E. Kim,,, S. R. Ehlert, M. L. Saade,, P. Kaaret, W. P. Maksym, C. T. Chen,, I. De La Calle Pérez, M. Perri,, F. Verrecchia,, O. Domann, S. Dürr, M. Feige, M. Heidemann, O. Koppitz, G. Manhalter, D. Reinhart, R. Steineke, C. Lorey, C. McCall, H. E. Jermak, I. A. Steele, V. Fallah Ramazani, J. Otero-Santos, D. Morcuende, F. J. Aceituno, V. Casanova, A. Sota, S. G. Jorstad, A. P. Marscher, C. Pauley, M. Sasada, K. S. Kawabata,,, M. Uemura,,, T. Mizuno, T. Nakaoka, H. Akitaya, I. Myserlis,, M. Gurwell, G. K. Keating, R. Rao, E. Angelakis and A. Kraus
Astronomy & Astrophysics Published:21 March 2025
DOI:https://doi.org/10.1051/0004-6361/202452785
Abstract
Context. Blazars exhibit strong variability across the entire electromagnetic spectrum, including periods of high-flux states commonly known as flares. The physical mechanisms in blazar jets responsible for flares remain poorly understood to date.
Aims. Our aim is to better understand the emission mechanisms during blazar flares using X-ray polarimetry and broadband observations from the archetypical TeV blazar Mrk 421, which can be studied with higher accuracy than other blazars that are dimmer and/or located farther away.
Methods. We studied a flaring activity from December 2023 that was characterized from radio to very high-energy (VHE; E > 0.1 TeV) gamma rays with MAGIC, Fermi-LAT, Swift, XMM-Newton, and several optical and radio telescopes. These observations included, for the first time for a gamma-ray flare of a blazar, simultaneous X-ray polarization measurements with IXPE, in addition to optical and radio polarimetry data. We quantify the variability and correlations among the multi-band flux and polarization measurements, and describe the varying broadband emission within a theoretical scenario constrained by the polarization data.
Results. We find substantial variability in both X-rays and VHE gamma rays throughout the campaign, with the highest VHE flux above 0.2 TeV occurring during the IXPE observing window, and exceeding twice the flux of the Crab Nebula. However, the VHE and X-ray spectra are on average softer, and the correlation between these two bands is weaker than those reported in the previous flares of Mrk 421. IXPE reveals an X-ray polarization degree significantly higher than that at radio and optical frequencies, similar to previous results for Mrk 421 and other high synchrotron peaked blazars. Differently to past observations, the X-ray polarization angle varies by ∼100° on timescales of days, and the polarization degree changes by more than a factor of 4. The highest X-ray polarization degree, analyzed in 12 h time intervals, reaches 26 ± 2%, around which an X-ray counter-clockwise hysteresis loop is measured with XMM-Newton. It suggests that the X-ray emission comes from particles close to the high-energy cutoff, hence possibly probing an extreme case of the Turbulent Extreme Multi-Zone model for which the chromatic trend in the polarization may be more pronounced than theoretically predicted. We model the broadband emission with a simplified stratified jet model throughout the flare. The polarization measurements imply an electron distribution in the X-ray emitting region with a very high minimum Lorentz factor (γ′min≳104), which is expected in electron-ion plasma, as well as a variation of the emitting region size of up to a factor of 3 during the flaring activity. We find no correlation between the fluxes and the evolution of the model parameters, which indicates a stochastic nature of the underlying physical mechanism that likely explains the lack of a tight X-ray/VHE correlation during this flaring activity. Such behavior would be expected in a highly turbulent electron-ion plasma crossing a shock front.
TeVブレイザーMrk 501の最初のX線偏光測定における広帯域放出の洞察 Insights into the broadband emission of the TeV blazar Mrk 501 during the first X-ray polarization measurements
MAGIC Collaboration
S. Abe, J. Abhir, V. A. Acciari, A. Aguasca-Cabot, I. Agudo, T. Aniello, S. Ansoldi,, L. A. Antonelli, A. Arbet Engels,⋆⋆, C. Arcaro, K. Asano, A. Babić, A. Baquero, U. Barres de Almeida, J. A. Barrio, I. Batković, A. Bautista, J. Baxter, J. Becerra González, W. Bednarek, E. Bernardini, M. Bernardos, J. Bernete, A. Berti, J. Besenrieder, C. Bigongiari, A. Biland, O. Blanch, G. Bonnoli, Ž. Bošnjak, I. Burelli, G. Busetto, A. Campoy-Ordaz, A. Carosi, R. Carosi, M. Carretero-Castrillo, A. J. Castro-Tirado, G. Ceribella, Y. Chai, A. Cifuentes, 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, R. de Menezes, A. Del Popolo, M. Delfino,, J. Delgado,, C. Delgado Mendez, F. Di Pierro, L. Di Venere, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, D. Elsaesser, G. Emery, J. Escudero, L. Fariña, A. Fattorini, L. Foffano, L. Font, S. Fröse, Y. Fukazawa, R. J. García López, M. Garczarczyk, S. Gasparyan, M. Gaug, J. G. Giesbrecht Paiva, N. Giglietto, F. Giordano, P. Gliwny, N. Godinović, T. Gradetzke, R. Grau, D. Green, J. G. Green, P. Günther, D. Hadasch, A. Hahn, T. Hassan, L. Heckmann,,⋆⋆, J. Herrera, D. Hrupec, M. Hütten, R. Imazawa, K. Ishio, I. Jiménez Martínez, T. Kayanoki, D. Kerszberg, G. W. Kluge,, Y. Kobayashi, P. M. Kouch, H. Kubo, J. Kushida, M. Láinez Lezáun, A. Lamastra, F. Leone, E. Lindfors, L. Linhoff, S. Lombardi, F. Longo,, R. López-Coto, M. López-Moya, A. López-Oramas, S. Loporchio, A. Lorini, E. Lyard, B. Machado de Oliveira Fraga, P. Majumdar, M. Makariev, G. Maneva, N. Mang, M. Manganaro, S. Mangano, K. Mannheim, M. Mariotti, M. Martínez, M. Martínez-Chicharro, A. Mas-Aguilar, D. Mazin,, S. Menchiari, S. Mender, D. Miceli, T. Miener, J. M. Miranda, R. Mirzoyan, M. Molero González, E. Molina, H. A. Mondal, A. Moralejo, D. Morcuende, T. Nakamori, C. Nanci, V. Neustroev, C. Nigro, L. Nikolić, K. Nilsson, K. Nishijima, T. Njoh Ekoume, K. Noda, S. Nozaki, Y. Ohtani, A. Okumura, J. Otero-Santos, S. Paiano, M. Palatiello, D. Paneque,⋆⋆, R. Paoletti, J. M. Paredes, M. Peresano, M. Persic,, M. Pihet, G. Pirola, F. Podobnik, P. G. Prada Moroni, E. Prandini, G. Principe, C. Priyadarshi, W. Rhode, M. Ribó, J. Rico, C. Righi, N. Sahakyan, T. Saito, K. Satalecka, F. G. Saturni, B. Schleicher, K. Schmidt, F. Schmuckermaier, J. L. Schubert, T. Schweizer, A. Sciaccaluga, G. Silvestri, J. Sitarek, D. Sobczynska, A. Spolon, A. Stamerra, J. Strišković, D. Strom, Y. Suda, S. Suutarinen, H. Tajima, M. Takahashi, R. Takeishi, F. Tavecchio, P. Temnikov, K. Terauchi, T. Terzić, M. Teshima,, L. Tosti, S. Truzzi, A. Tutone, S. Ubach, J. van Scherpenberg, S. Ventura, I. Viale, C. F. Vigorito, V. Vitale, I. Vovk, R. Walter, M. Will, C. Wunderlich and T. Yamamoto
Multi-wavelength collaborators
I. Liodakis,, F. J. Aceituno, B. Agís-González, H. Akitaya, M. I. Bernardos, D. Blinov,, I. G. Bourbah, C. Casadio,, V. Casanova, F. D’Ammando, V. Fallah Ramazani, E. Fernández-García, Y. Fukazawa,,, M. García-Comas, E. Gau, A. Gokus, M. Gurwell, P. Hakala, T. Hovatta,, Y.-D. Hu,, C. Husillos,, J. Jormanainen,, S. G. Jorstad, K. S. Kawabata,,, G. K. Keating, S. Kiehlmann,, E. Kontopodis, H. Krawczynski, A. Lähteenmäki,, C. Leto,, L. Lisalda, N. Mandarakas,, A. Marchini, A. P. Marscher, W. Max-Moerbeck, R. Middei,, T. Mizuno, I. Myserlis, T. Nakaoka, M. Perri,, S. Puccetti, R. Rao, A. C. S. Readhead, R. Reeves, N. Rodriguez Cavero, Q. Salomé,, M. Sasada,, R. Skalidis,,, A. Sota, I. Syrjärinne,, M. Tornikoski, M. Uemura,,, F. Verrecchia, and A. Vervelaki
Astronomy & Astrophysics Published:22 May 2024
DOI:https://doi.org/10.1051/0004-6361/202348709
Abstract
Aims. We present the first multiwavelength study of Mrk 501 that contains simultaneous very-high-energy (VHE) γ-ray observations and X-ray polarization measurements from the Imaging X-ray Polarimetry Explorer (IXPE).
Methods. We used radio-to-VHE data from a multiwavelength campaign carried out between March 1, 2022, and July 19, 2022 (MJD 59639 to MJD 59779). The observations were performed by MAGIC, Fermi-LAT, NuSTAR, Swift (XRT and UVOT), and several other instruments that cover the optical and radio bands to complement the IXPE pointings. We characterized the dynamics of the broadband emission around the X-ray polarization measurements through its multiband fractional variability and correlations, and compared changes observed in the polarization degree to changes seen in the broadband emission using a multi-zone leptonic scenario.
Results. During the IXPE pointings, the VHE state is close to the average behavior, with a 0.2–1 TeV flux of 20%–50% of the emission of the Crab Nebula. Additionally, it shows low variability and a hint of correlation between VHE γ-rays and X-rays. Despite the average VHE activity, an extreme X-ray behavior is measured for the first two IXPE pointings, taken in March 2022 (MJD 59646 to 59648 and MJD 59665 to 59667), with a synchrotron peak frequency > 1 keV. For the third IXPE pointing, in July 2022 (MJD 59769 to 59772), the synchrotron peak shifts toward lower energies and the optical/X-ray polarization degrees drop. All three IXPE epochs show an atypically low Compton dominance in the γ-rays. The X-ray polarization is systematically higher than at lower energies, suggesting an energy stratification of the jet. While during the IXPE epochs the polarization angles in the X-ray, optical, and radio bands align well, we find a clear discrepancy in the optical and radio polarization angles in the middle of the campaign. Such results further support the hypothesis of an energy-stratified jet. We modeled broadband spectra taken simultaneous to the IXPE pointings, assuming a compact zone that dominates in the X-rays and the VHE band, and an extended zone stretching farther downstream in the jet that dominates the emission at lower energies. NuSTAR data allow us to precisely constrain the synchrotron peak and therefore the underlying electron distribution. The change between the different states observed in the three IXPE pointings can be explained by a change in the magnetization and/or the emission region size, which directly connects the shift in the synchrotron peak to lower energies with the drop in the polarization degree.
X線偏光測定と同時にMrk 421の電波から超高エネルギーガンマ線までの放射挙動を初めて明らかにする First characterization of the emission behavior of Mrk 421 from radio to very high-energy gamma rays with simultaneous X-ray polarization measurements
S. Abe, J. Abhir, V. A. Acciari, I. Agudo, T. Aniello, S. Ansoldi,, L. A. Antonelli, A. Arbet-Engels,⋆⋆, C. Arcaro, M. Artero, K. Asano, A. Babić, A. Baquero, U. Barres de Almeida, J. A. Barrio, I. Batković, J. Baxter, J. Becerra González, W. Bednarek, E. Bernardini, J. Bernete, A. Berti, J. Besenrieder, C. Bigongiari, A. Biland, O. Blanch, G. Bonnoli, Ž. Bošnjak, I. Burelli, G. Busetto, A. Campoy-Ordaz, A. Carosi, R. Carosi, M. Carretero-Castrillo, A. J. Castro-Tirado, G. Ceribella, Y. Chai, A. Cifuentes, S. Cikota, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, F. D’Ammando, G. D’Amico, V. D’Elia, P. Da Vela,, F. Dazzi, A. De Angelis, B. De Lotto, R. de Menezes, A. Del Popolo, J. Delgado,, C. Delgado Mendez, F. Di Pierro, L. Di Venere, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, D. Elsaesser, G. Emery, J. Escudero, L. Fariña, A. Fattorini, L. Foffano, L. Font, S. Fröse, S. Fukami, Y. Fukazawa, R. J. García López, M. Garczarczyk, S. Gasparyan, M. Gaug, J. G. Giesbrecht Paiva, N. Giglietto, F. Giordano, P. Gliwny, N. Godinović, T. Gradetzke, R. Grau, D. Green, J. G. Green, P. Günther, D. Hadasch, A. Hahn, T. Hassan, L. Heckmann,, J. Herrera, D. Hrupec, M. Hütten, R. Imazawa, T. Inada, K. Ishio, I. Jiménez Martínez, J. Jormanainen, D. Kerszberg, G. W. Kluge,, Y. Kobayashi, P. M. Kouch, H. Kubo, J. Kushida, M. Láinez Lezáun, A. Lamastra, F. Leone, E. Lindfors, L. Linhoff, S. Lombardi, F. Longo,, R. López-Coto, M. López-Moya, A. López-Oramas, S. Loporchio, A. Lorini, B. Machado de Oliveira Fraga, P. Majumdar, M. Makariev, G. Maneva, N. Mang, M. Manganaro, S. Mangano, K. Mannheim, M. Mariotti, M. Martínez, M. Martínez-Chicharro, A. Mas-Aguilar, D. Mazin,, S. Menchiari, S. Mender, D. Miceli, T. Miener, J. M. Miranda, R. Mirzoyan, M. Molero González, E. Molina, H. A. Mondal, A. Moralejo, D. Morcuende, T. Nakamori, C. Nanci, L. Nava, V. Neustroev, L. Nickel, M. Nievas Rosillo, C. Nigro, L. Nikolić, K. Nilsson, K. Nishijima, T. Njoh Ekoume, K. Noda, S. Nozaki, Y. Ohtani, A. Okumura, J. Otero-Santos, S. Paiano, M. Palatiello, D. Paneque,⋆⋆, R. Paoletti, J. M. Paredes, D. Pavlović, M. Peresano, M. Persic,, M. Pihet, G. Pirola, F. Podobnik, P. G. Prada Moroni, E. Prandini, G. Principe, C. Priyadarshi, W. Rhode, M. Ribó, J. Rico, C. Righi, N. Sahakyan, T. Saito, K. Satalecka, F. G. Saturni, B. Schleicher, K. Schmidt, F. Schmuckermaier,,⋆⋆, J. L. Schubert, T. Schweizer, A. Sciaccaluga, J. Sitarek, V. Sliusar, D. Sobczynska, A. Stamerra, J. Strišković, D. Strom, M. Strzys, Y. Suda, S. Suutarinen, H. Tajima, M. Takahashi, R. Takeishi, F. Tavecchio, P. Temnikov, K. Terauchi, T. Terzić, M. Teshima,, L. Tosti, S. Truzzi, A. Tutone, S. Ubach, J. van Scherpenberg, M. Vazquez Acosta, S. Ventura, I. Viale, C. F. Vigorito, V. Vitale, I. Vovk, R. Walter, M. Will, C. Wunderlich, T. Yamamoto, I. Liodakis,, S. G. Jorstad, L. Di Gesu, I. Donnarumma, D. E. Kim,,, A. P. Marscher, R. Middei,, M. Perri,, S. Puccetti, F. Verrecchia,, C. Leto, I. De La Calle Pérez, E. Jiménez-Bailón, D. Blinov,,, I. G. Bourbah, S. Kiehlmann,, E. Kontopodis, N. Mandarakas,, R. Skalidis, A. Vervelaki, F. J. Aceituno, B. Agís-González, A. Sota, M. Sasada, Y. Fukazawa,,, K. S. Kawabata,,, M. Uemura,,, T. Mizuno, H. Akitaya, C. Casadio,, I. Myserlis,, A. Sievers, A. Lähteenmäki,, I. Syrjärinne,, M. Tornikoski, Q. Salomé,, M. Gurwell, G. K. Keating and R. Rao
Astronomy & Astrophysics Published:11 April 2024
DOI:https://doi.org/10.1051/0004-6361/202347988
Abstract
Aims. We have performed the first broadband study of Mrk 421 from radio to TeV gamma rays with simultaneous measurements of the X-ray polarization from IXPE.
Methods. The data were collected as part of an extensive multiwavelength campaign carried out between May and June 2022 using MAGIC, Fermi-LAT, NuSTAR, XMM-Newton, Swift, and several optical and radio telescopes to complement IXPE data.
Results. During the IXPE exposures, the measured 0.2–1 TeV flux was close to the quiescent state and ranged from 25% to 50% of the Crab Nebula without intra-night variability. Throughout the campaign, the very high-energy (VHE) and X-ray emission are positively correlated at a 4σ significance level. The IXPE measurements reveal an X-ray polarization degree that is a factor of 2–5 higher than in the optical/radio bands; that implies an energy-stratified jet in which the VHE photons are emitted co-spatially with the X-rays, in the vicinity of a shock front. The June 2022 observations exhibit a rotation of the X-ray polarization angle. Despite no simultaneous VHE coverage being available during a large fraction of the swing, the Swift-XRT monitoring reveals an X-ray flux increase with a clear spectral hardening. This suggests that flares in high synchrotron peaked blazars can be accompanied by a polarization angle rotation, as observed in some flat spectrum radio quasars. Finally, during the polarization angle rotation, NuSTAR data reveal two contiguous spectral hysteresis loops in opposite directions (clockwise and counterclockwise), implying important changes in the particle acceleration efficiency on approximately hour timescales.
