Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays

J. Aleksić; S. Ansoldi; L. A. Antonelli; P. Antoranz; A. Babic; P. Bangale; U. Barres De Almeida; J. A. Barrio; J. Becerra González; W. Bednarek; K. Berger; E. Bernardini; A. Biland; O. Blanch; R. K. Bock; S. Bonnefoy; G. Bonnoli; F. Borracci; T. Bretz; E. Carmona; A. Carosi; D. Carreto Fidalgo; P. Colin; E. Colombo; J. L. Contreras; J. Cortina; S. Covino; P. Da Vela; F. Dazzi; A. De Angelis; G. De Caneva; B. De Lotto; C. Delgado Mendez; M. Doert; A. Domínguez; D. Dominis Prester; D. Dorner; M. Doro; S. Einecke; D. Eisenacher; D. Elsaesser; E. Farina; D. Ferenc; M. V. Fonseca; L. Font; K. Frantzen; C. Fruck; R. J. García López; M. Garczarczyk; D. Garrido Terrats; M. Gaug; G. Giavitto; N. Godinović; A. González Muñoz; S. R. Gozzini; A. Hadamek; D. Hadasch; A. Herrero; D. Hildebrand; J. Hose; D. Hrupec; W. Idec; V. Kadenius; H. Kellermann; M. L. Knoetig; J. Krause; J. Kushida; A. La Barbera; D. Lelas; N. Lewandowska; E. Lindfors; S. Lombardi; M. López; R. López-Coto; A. López-Oramas; E. Lorenz; I. Lozano; M. Makariev; K. Mallot; G. Maneva; N. Mankuzhiyil; K. Mannheim; L. Maraschi; B. Marcote; M. Mariotti; M. Martínez; D. Mazin; U. Menzel; M. Meucci; J. M. Miranda; R. Mirzoyan; A. Moralejo; P. Munar-Adrover; D. Nakajima; A. Niedzwiecki; K. Nilsson; N. Nowak; R. Orito; A. Overkemping; S. Paiano

doi:10.1051/0004-6361/201322951

Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays

J. Aleksić, S. Ansoldi, L. A. Antonelli, P. Antoranz, A. Babic, P. Bangale, U. Barres De Almeida, J. A. Barrio, J. Becerra González, W. Bednarek, K. Berger, E. Bernardini, A. Biland, O. Blanch, R. K. Bock, S. Bonnefoy, G. Bonnoli, F. Borracci, T. Bretz, E. CarmonaA. Carosi, D. Carreto Fidalgo, P. Colin, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, P. Da Vela, F. Dazzi, A. De Angelis, G. De Caneva, B. De Lotto, C. Delgado Mendez, M. Doert, A. Domínguez, D. Dominis Prester, D. Dorner, M. Doro, S. Einecke, D. Eisenacher, D. Elsaesser, E. Farina, D. Ferenc, M. V. Fonseca, L. Font, K. Frantzen, C. Fruck, R. J. García López, M. Garczarczyk, D. Garrido Terrats, M. Gaug, G. Giavitto, N. Godinović, A. González Muñoz, S. R. Gozzini, A. Hadamek, D. Hadasch, A. Herrero, D. Hildebrand, J. Hose, D. Hrupec, W. Idec, V. Kadenius, H. Kellermann, M. L. Knoetig, J. Krause, J. Kushida, A. La Barbera, D. Lelas, N. Lewandowska, E. Lindfors, S. Lombardi, M. López, R. López-Coto, A. López-Oramas, E. Lorenz, I. Lozano, M. Makariev, K. Mallot, G. Maneva, N. Mankuzhiyil, K. Mannheim, L. Maraschi, B. Marcote, M. Mariotti, M. Martínez, D. Mazin, U. Menzel, M. Meucci, J. M. Miranda, R. Mirzoyan, A. Moralejo, P. Munar-Adrover, D. Nakajima, A. Niedzwiecki, K. Nilsson, N. Nowak, R. Orito, A. Overkemping, S. Paiano

Research output: Contribution to journal › Article › Research › peer-review

41 Citations (Scopus)

Abstract

Aims. The radio galaxy NGCâ‰ 1275, recently identified as a very high energy (VHE, >100 GeV) γ-ray emitter by MAGIC, is one of the few non-blazar active galactic nuclei detected in the VHE regime. The purpose of this work is to better understand the origin of the γ-ray emission and locate it within the galaxy. Methods. We studied contemporaneous multifrequency observations of NGCâ‰ 1275 and modeled the overall spectral energy distribution. We analyzed unpublished MAGIC observations carried out between October 2009 and February 2010, and the previously published observations taken between August 2010 and February 2011. We studied the multiband variability and correlations by analyzing data of Fermi-LAT in the 100 MeV-100 GeV energy band, as well as Chandra (X-ray), KVA (optical), and MOJAVE (radio) data taken during the same period. Results. Using customized Monte Carlo simulations corresponding to early MAGIC stereoscopic data, we detect NGCâ‰ 1275 also in the earlier MAGIC campaign. The flux level and energy spectra are similar to the results of the second campaign. The monthly light curve above 100 GeV shows a hint of variability at the 3.6σ level. In the Fermi-LAT band, both flux and spectral shape variabilities are reported. The optical light curve is also variable and shows a clear correlation with the γ-ray flux above 100 MeV. In radio, three compact components are resolved in the innermost part of the jet. One of these components shows a similar trend as the Fermi-LAT and KVA light curves. The γ-ray spectra measured simultaneously with MAGIC and Fermi-LAT from 100 MeV to 650 GeV can be well fitted either by a log-parabola or by a power-law with a subexponential cutoff for the two observation campaigns. A single-zone synchrotron-self-Compton model, with an electron spectrum following a power-law with an exponential cutoff, can explain the broadband spectral energy distribution and the multifrequency behavior of the source. However, this model suggests an untypical low bulk-Lorentz factor or a velocity alignment closer to the line of sight than the parsec-scale radio jet. © 2014 ESO.

Original language	English
Article number	A5
Journal	Astronomy and Astrophysics
Volume	564
DOIs	https://doi.org/10.1051/0004-6361/201322951
Publication status	Published - 1 Jan 2014

Keywords

Galaxies: active
Galaxies: individual: NGC 1275
Galaxies: jets
Gamma rays: galaxies

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10.1051/0004-6361/201322951

Cite this

Aleksić, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., ... Paiano, S. (2014). Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays. Astronomy and Astrophysics, 564, [A5]. https://doi.org/10.1051/0004-6361/201322951

Aleksić, J. ; Ansoldi, S. ; Antonelli, L. A. ; Antoranz, P. ; Babic, A. ; Bangale, P. ; Barres De Almeida, U. ; Barrio, J. A. ; Becerra González, J. ; Bednarek, W. ; Berger, K. ; Bernardini, E. ; Biland, A. ; Blanch, O. ; Bock, R. K. ; Bonnefoy, S. ; Bonnoli, G. ; Borracci, F. ; Bretz, T. ; Carmona, E. ; Carosi, A. ; Carreto Fidalgo, D. ; Colin, P. ; Colombo, E. ; Contreras, J. L. ; Cortina, J. ; Covino, S. ; Da Vela, P. ; Dazzi, F. ; De Angelis, A. ; De Caneva, G. ; De Lotto, B. ; Delgado Mendez, C. ; Doert, M. ; Domínguez, A. ; Dominis Prester, D. ; Dorner, D. ; Doro, M. ; Einecke, S. ; Eisenacher, D. ; Elsaesser, D. ; Farina, E. ; Ferenc, D. ; Fonseca, M. V. ; Font, L. ; Frantzen, K. ; Fruck, C. ; García López, R. J. ; Garczarczyk, M. ; Garrido Terrats, D. ; Gaug, M. ; Giavitto, G. ; Godinović, N. ; González Muñoz, A. ; Gozzini, S. R. ; Hadamek, A. ; Hadasch, D. ; Herrero, A. ; Hildebrand, D. ; Hose, J. ; Hrupec, D. ; Idec, W. ; Kadenius, V. ; Kellermann, H. ; Knoetig, M. L. ; Krause, J. ; Kushida, J. ; La Barbera, A. ; Lelas, D. ; Lewandowska, N. ; Lindfors, E. ; Lombardi, S. ; López, M. ; López-Coto, R. ; López-Oramas, A. ; Lorenz, E. ; Lozano, I. ; Makariev, M. ; Mallot, K. ; Maneva, G. ; Mankuzhiyil, N. ; Mannheim, K. ; Maraschi, L. ; Marcote, B. ; Mariotti, M. ; Martínez, M. ; Mazin, D. ; Menzel, U. ; Meucci, M. ; Miranda, J. M. ; Mirzoyan, R. ; Moralejo, A. ; Munar-Adrover, P. ; Nakajima, D. ; Niedzwiecki, A. ; Nilsson, K. ; Nowak, N. ; Orito, R. ; Overkemping, A. ; Paiano, S. / Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays. In: Astronomy and Astrophysics. 2014 ; Vol. 564.

@article{2a4726e3e8de4195b3d9fcb9d3d6b395,

title = "Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays",

abstract = "Aims. The radio galaxy NGC{\^a}‰ 1275, recently identified as a very high energy (VHE, >100 GeV) γ-ray emitter by MAGIC, is one of the few non-blazar active galactic nuclei detected in the VHE regime. The purpose of this work is to better understand the origin of the γ-ray emission and locate it within the galaxy. Methods. We studied contemporaneous multifrequency observations of NGC{\^a}‰ 1275 and modeled the overall spectral energy distribution. We analyzed unpublished MAGIC observations carried out between October 2009 and February 2010, and the previously published observations taken between August 2010 and February 2011. We studied the multiband variability and correlations by analyzing data of Fermi-LAT in the 100 MeV-100 GeV energy band, as well as Chandra (X-ray), KVA (optical), and MOJAVE (radio) data taken during the same period. Results. Using customized Monte Carlo simulations corresponding to early MAGIC stereoscopic data, we detect NGC{\^a}‰ 1275 also in the earlier MAGIC campaign. The flux level and energy spectra are similar to the results of the second campaign. The monthly light curve above 100 GeV shows a hint of variability at the 3.6σ level. In the Fermi-LAT band, both flux and spectral shape variabilities are reported. The optical light curve is also variable and shows a clear correlation with the γ-ray flux above 100 MeV. In radio, three compact components are resolved in the innermost part of the jet. One of these components shows a similar trend as the Fermi-LAT and KVA light curves. The γ-ray spectra measured simultaneously with MAGIC and Fermi-LAT from 100 MeV to 650 GeV can be well fitted either by a log-parabola or by a power-law with a subexponential cutoff for the two observation campaigns. A single-zone synchrotron-self-Compton model, with an electron spectrum following a power-law with an exponential cutoff, can explain the broadband spectral energy distribution and the multifrequency behavior of the source. However, this model suggests an untypical low bulk-Lorentz factor or a velocity alignment closer to the line of sight than the parsec-scale radio jet. {\textcopyright} 2014 ESO.",

keywords = "Galaxies: active, Galaxies: individual: NGC 1275, Galaxies: jets, Gamma rays: galaxies",

author = "J. Aleksi{\'c} and S. Ansoldi and Antonelli, {L. A.} and P. Antoranz and A. Babic and P. Bangale and {Barres De Almeida}, U. and Barrio, {J. A.} and {Becerra Gonz{\'a}lez}, J. and W. Bednarek and K. Berger and E. Bernardini and A. Biland and O. Blanch and Bock, {R. K.} and S. Bonnefoy and G. Bonnoli and F. Borracci and T. Bretz and E. Carmona and A. Carosi and {Carreto Fidalgo}, D. and P. Colin and E. Colombo and Contreras, {J. L.} and J. Cortina and S. Covino and {Da Vela}, P. and F. Dazzi and {De Angelis}, A. and {De Caneva}, G. and {De Lotto}, B. and {Delgado Mendez}, C. and M. Doert and A. Dom{\'i}nguez and {Dominis Prester}, D. and D. Dorner and M. Doro and S. Einecke and D. Eisenacher and D. Elsaesser and E. Farina and D. Ferenc and Fonseca, {M. V.} and L. Font and K. Frantzen and C. Fruck and {Garc{\'i}a L{\'o}pez}, {R. J.} and M. Garczarczyk and {Garrido Terrats}, D. and M. Gaug and G. Giavitto and N. Godinovi{\'c} and {Gonz{\'a}lez Mu{\~n}oz}, A. and Gozzini, {S. R.} and A. Hadamek and D. Hadasch and A. Herrero and D. Hildebrand and J. Hose and D. Hrupec and W. Idec and V. Kadenius and H. Kellermann and Knoetig, {M. L.} and J. Krause and J. Kushida and {La Barbera}, A. and D. Lelas and N. Lewandowska and E. Lindfors and S. Lombardi and M. L{\'o}pez and R. L{\'o}pez-Coto and A. L{\'o}pez-Oramas and E. Lorenz and I. Lozano and M. Makariev and K. Mallot and G. Maneva and N. Mankuzhiyil and K. Mannheim and L. Maraschi and B. Marcote and M. Mariotti and M. Mart{\'i}nez and D. Mazin and U. Menzel and M. Meucci and Miranda, {J. M.} and R. Mirzoyan and A. Moralejo and P. Munar-Adrover and D. Nakajima and A. Niedzwiecki and K. Nilsson and N. Nowak and R. Orito and A. Overkemping and S. Paiano",

year = "2014",

month = jan,

day = "1",

doi = "10.1051/0004-6361/201322951",

language = "English",

volume = "564",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

}

Aleksić, J, Ansoldi, S, Antonelli, LA, Antoranz, P, Babic, A, Bangale, P, Barres De Almeida, U, Barrio, JA, Becerra González, J, Bednarek, W, Berger, K, Bernardini, E, Biland, A, Blanch, O, Bock, RK, Bonnefoy, S, Bonnoli, G, Borracci, F, Bretz, T, Carmona, E, Carosi, A, Carreto Fidalgo, D, Colin, P, Colombo, E, Contreras, JL, Cortina, J, Covino, S, Da Vela, P, Dazzi, F, De Angelis, A, De Caneva, G, De Lotto, B, Delgado Mendez, C, Doert, M, Domínguez, A, Dominis Prester, D, Dorner, D, Doro, M, Einecke, S, Eisenacher, D, Elsaesser, D, Farina, E, Ferenc, D, Fonseca, MV, Font, L, Frantzen, K, Fruck, C, García López, RJ, Garczarczyk, M, Garrido Terrats, D, Gaug, M, Giavitto, G, Godinović, N, González Muñoz, A, Gozzini, SR, Hadamek, A, Hadasch, D, Herrero, A, Hildebrand, D, Hose, J, Hrupec, D, Idec, W, Kadenius, V, Kellermann, H, Knoetig, ML, Krause, J, Kushida, J, La Barbera, A, Lelas, D, Lewandowska, N, Lindfors, E, Lombardi, S, López, M, López-Coto, R, López-Oramas, A, Lorenz, E, Lozano, I, Makariev, M, Mallot, K, Maneva, G, Mankuzhiyil, N, Mannheim, K, Maraschi, L, Marcote, B, Mariotti, M, Martínez, M, Mazin, D, Menzel, U, Meucci, M, Miranda, JM, Mirzoyan, R, Moralejo, A, Munar-Adrover, P, Nakajima, D, Niedzwiecki, A, Nilsson, K, Nowak, N, Orito, R, Overkemping, A & Paiano, S 2014, 'Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays', Astronomy and Astrophysics, vol. 564, A5. https://doi.org/10.1051/0004-6361/201322951

Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays. / Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barres De Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Carreto Fidalgo, D.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; Delgado Mendez, C.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Farina, E.; Ferenc, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giavitto, G.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Hadamek, A.; Hadasch, D.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Krause, J.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Niedzwiecki, A.; Nilsson, K.; Nowak, N.; Orito, R.; Overkemping, A.; Paiano, S.

In: Astronomy and Astrophysics, Vol. 564, A5, 01.01.2014.

Research output: Contribution to journal › Article › Research › peer-review

TY - JOUR

T1 - Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays

AU - Aleksić, J.

AU - Ansoldi, S.

AU - Antonelli, L. A.

AU - Antoranz, P.

AU - Babic, A.

AU - Bangale, P.

AU - Barres De Almeida, U.

AU - Barrio, J. A.

AU - Becerra González, J.

AU - Bednarek, W.

AU - Berger, K.

AU - Bernardini, E.

AU - Biland, A.

AU - Blanch, O.

AU - Bock, R. K.

AU - Bonnefoy, S.

AU - Bonnoli, G.

AU - Borracci, F.

AU - Bretz, T.

AU - Carmona, E.

AU - Carosi, A.

AU - Carreto Fidalgo, D.

AU - Colin, P.

AU - Colombo, E.

AU - Contreras, J. L.

AU - Cortina, J.

AU - Covino, S.

AU - Da Vela, P.

AU - Dazzi, F.

AU - De Angelis, A.

AU - De Caneva, G.

AU - De Lotto, B.

AU - Delgado Mendez, C.

AU - Doert, M.

AU - Domínguez, A.

AU - Dominis Prester, D.

AU - Dorner, D.

AU - Doro, M.

AU - Einecke, S.

AU - Eisenacher, D.

AU - Elsaesser, D.

AU - Farina, E.

AU - Ferenc, D.

AU - Fonseca, M. V.

AU - Font, L.

AU - Frantzen, K.

AU - Fruck, C.

AU - García López, R. J.

AU - Garczarczyk, M.

AU - Garrido Terrats, D.

AU - Gaug, M.

AU - Giavitto, G.

AU - Godinović, N.

AU - González Muñoz, A.

AU - Gozzini, S. R.

AU - Hadamek, A.

AU - Hadasch, D.

AU - Herrero, A.

AU - Hildebrand, D.

AU - Hose, J.

AU - Hrupec, D.

AU - Idec, W.

AU - Kadenius, V.

AU - Kellermann, H.

AU - Knoetig, M. L.

AU - Krause, J.

AU - Kushida, J.

AU - La Barbera, A.

AU - Lelas, D.

AU - Lewandowska, N.

AU - Lindfors, E.

AU - Lombardi, S.

AU - López, M.

AU - López-Coto, R.

AU - López-Oramas, A.

AU - Lorenz, E.

AU - Lozano, I.

AU - Makariev, M.

AU - Mallot, K.

AU - Maneva, G.

AU - Mankuzhiyil, N.

AU - Mannheim, K.

AU - Maraschi, L.

AU - Marcote, B.

AU - Mariotti, M.

AU - Martínez, M.

AU - Mazin, D.

AU - Menzel, U.

AU - Meucci, M.

AU - Miranda, J. M.

AU - Mirzoyan, R.

AU - Moralejo, A.

AU - Munar-Adrover, P.

AU - Nakajima, D.

AU - Niedzwiecki, A.

AU - Nilsson, K.

AU - Nowak, N.

AU - Orito, R.

AU - Overkemping, A.

AU - Paiano, S.

PY - 2014/1/1

Y1 - 2014/1/1

N2 - Aims. The radio galaxy NGCâ‰ 1275, recently identified as a very high energy (VHE, >100 GeV) γ-ray emitter by MAGIC, is one of the few non-blazar active galactic nuclei detected in the VHE regime. The purpose of this work is to better understand the origin of the γ-ray emission and locate it within the galaxy. Methods. We studied contemporaneous multifrequency observations of NGCâ‰ 1275 and modeled the overall spectral energy distribution. We analyzed unpublished MAGIC observations carried out between October 2009 and February 2010, and the previously published observations taken between August 2010 and February 2011. We studied the multiband variability and correlations by analyzing data of Fermi-LAT in the 100 MeV-100 GeV energy band, as well as Chandra (X-ray), KVA (optical), and MOJAVE (radio) data taken during the same period. Results. Using customized Monte Carlo simulations corresponding to early MAGIC stereoscopic data, we detect NGCâ‰ 1275 also in the earlier MAGIC campaign. The flux level and energy spectra are similar to the results of the second campaign. The monthly light curve above 100 GeV shows a hint of variability at the 3.6σ level. In the Fermi-LAT band, both flux and spectral shape variabilities are reported. The optical light curve is also variable and shows a clear correlation with the γ-ray flux above 100 MeV. In radio, three compact components are resolved in the innermost part of the jet. One of these components shows a similar trend as the Fermi-LAT and KVA light curves. The γ-ray spectra measured simultaneously with MAGIC and Fermi-LAT from 100 MeV to 650 GeV can be well fitted either by a log-parabola or by a power-law with a subexponential cutoff for the two observation campaigns. A single-zone synchrotron-self-Compton model, with an electron spectrum following a power-law with an exponential cutoff, can explain the broadband spectral energy distribution and the multifrequency behavior of the source. However, this model suggests an untypical low bulk-Lorentz factor or a velocity alignment closer to the line of sight than the parsec-scale radio jet. © 2014 ESO.

AB - Aims. The radio galaxy NGCâ‰ 1275, recently identified as a very high energy (VHE, >100 GeV) γ-ray emitter by MAGIC, is one of the few non-blazar active galactic nuclei detected in the VHE regime. The purpose of this work is to better understand the origin of the γ-ray emission and locate it within the galaxy. Methods. We studied contemporaneous multifrequency observations of NGCâ‰ 1275 and modeled the overall spectral energy distribution. We analyzed unpublished MAGIC observations carried out between October 2009 and February 2010, and the previously published observations taken between August 2010 and February 2011. We studied the multiband variability and correlations by analyzing data of Fermi-LAT in the 100 MeV-100 GeV energy band, as well as Chandra (X-ray), KVA (optical), and MOJAVE (radio) data taken during the same period. Results. Using customized Monte Carlo simulations corresponding to early MAGIC stereoscopic data, we detect NGCâ‰ 1275 also in the earlier MAGIC campaign. The flux level and energy spectra are similar to the results of the second campaign. The monthly light curve above 100 GeV shows a hint of variability at the 3.6σ level. In the Fermi-LAT band, both flux and spectral shape variabilities are reported. The optical light curve is also variable and shows a clear correlation with the γ-ray flux above 100 MeV. In radio, three compact components are resolved in the innermost part of the jet. One of these components shows a similar trend as the Fermi-LAT and KVA light curves. The γ-ray spectra measured simultaneously with MAGIC and Fermi-LAT from 100 MeV to 650 GeV can be well fitted either by a log-parabola or by a power-law with a subexponential cutoff for the two observation campaigns. A single-zone synchrotron-self-Compton model, with an electron spectrum following a power-law with an exponential cutoff, can explain the broadband spectral energy distribution and the multifrequency behavior of the source. However, this model suggests an untypical low bulk-Lorentz factor or a velocity alignment closer to the line of sight than the parsec-scale radio jet. © 2014 ESO.

KW - Galaxies: active

KW - Galaxies: individual: NGC 1275

KW - Galaxies: jets

KW - Gamma rays: galaxies

U2 - 10.1051/0004-6361/201322951

DO - 10.1051/0004-6361/201322951

M3 - Article

VL - 564

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - A5

ER -

Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays

Abstract

Keywords

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Cite this