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 & 138 others 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, M. Palatiello, D. Paneque, R. Paoletti, J. M. Paredes, X. Paredes-Fortuny, S. Partini, M. Persic, F. Prada, P. G. Prada Moroni, E. Prandini, S. Preziuso, I. Puljak, R. Reinthal, W. Rhode, M. Ribó, J. Rico, J. Rodriguez Garcia, S. Rügamer, A. Saggion, T. Saito, K. Saito, M. Salvati, K. Satalecka, V. Scalzotto, V. Scapin, C. Schultz, T. Schweizer, S. N. Shore, A. Sillanpää, J. Sitarek, I. Snidaric, D. Sobczynska, F. Spanier, V. Stamatescu, A. Stamerra, T. Steinbring, J. Storz, S. Sun, T. Surić, L. Takalo, F. Tavecchio, T. Terzić, D. Tescaro, M. Teshima, J. Thaele, O. Tibolla, D. F. Torres, T. Toyama, A. Treves, M. Uellenbeck, P. Vogler, R. M. Wagner, F. Zandanel, R. Zanin, B. Balmaverde, Jun Kataoka, R. Rekola, Y. Takahashi

    Research output: Contribution to journalArticle

    32 Citations (Scopus)

    Abstract

    Aims. The radio galaxy NGC≠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≠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≠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.

    Original languageEnglish
    Article numberA5
    JournalAstronomy and Astrophysics
    Volume564
    DOIs
    Publication statusPublished - 2014

    Fingerprint

    radio galaxies
    rays
    radio
    light curve
    spectral energy distribution
    energy
    cut-off
    power law
    parabolas
    active galactic nuclei
    line of sight
    energy bands
    synchrotrons
    emitters
    energy spectra
    alignment
    galaxies
    broadband
    trends
    electron

    Keywords

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

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

    Cite this

    Aleksić, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., ... Takahashi, Y. (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

    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.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Partini, S.; Persic, M.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Preziuso, S.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saggion, A.; Saito, T.; Saito, K.; Salvati, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamatescu, V.; Stamerra, A.; Steinbring, T.; Storz, J.; Sun, S.; Surić, T.; Takalo, L.; Tavecchio, F.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Uellenbeck, M.; Vogler, P.; Wagner, R. M.; Zandanel, F.; Zanin, R.; Balmaverde, B.; Kataoka, Jun; Rekola, R.; Takahashi, Y.

    In: Astronomy and Astrophysics, Vol. 564, A5, 2014.

    Research output: Contribution to journalArticle

    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, Palatiello, M, Paneque, D, Paoletti, R, Paredes, JM, Paredes-Fortuny, X, Partini, S, Persic, M, Prada, F, Prada Moroni, PG, Prandini, E, Preziuso, S, Puljak, I, Reinthal, R, Rhode, W, Ribó, M, Rico, J, Rodriguez Garcia, J, Rügamer, S, Saggion, A, Saito, T, Saito, K, Salvati, M, Satalecka, K, Scalzotto, V, Scapin, V, Schultz, C, Schweizer, T, Shore, SN, Sillanpää, A, Sitarek, J, Snidaric, I, Sobczynska, D, Spanier, F, Stamatescu, V, Stamerra, A, Steinbring, T, Storz, J, Sun, S, Surić, T, Takalo, L, Tavecchio, F, Terzić, T, Tescaro, D, Teshima, M, Thaele, J, Tibolla, O, Torres, DF, Toyama, T, Treves, A, Uellenbeck, M, Vogler, P, Wagner, RM, Zandanel, F, Zanin, R, Balmaverde, B, Kataoka, J, Rekola, R & Takahashi, Y 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
    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. ; Palatiello, M. ; Paneque, D. ; Paoletti, R. ; Paredes, J. M. ; Paredes-Fortuny, X. ; Partini, S. ; Persic, M. ; Prada, F. ; Prada Moroni, P. G. ; Prandini, E. ; Preziuso, S. ; Puljak, I. ; Reinthal, R. ; Rhode, W. ; Ribó, M. ; Rico, J. ; Rodriguez Garcia, J. ; Rügamer, S. ; Saggion, A. ; Saito, T. ; Saito, K. ; Salvati, M. ; Satalecka, K. ; Scalzotto, V. ; Scapin, V. ; Schultz, C. ; Schweizer, T. ; Shore, S. N. ; Sillanpää, A. ; Sitarek, J. ; Snidaric, I. ; Sobczynska, D. ; Spanier, F. ; Stamatescu, V. ; Stamerra, A. ; Steinbring, T. ; Storz, J. ; Sun, S. ; Surić, T. ; Takalo, L. ; Tavecchio, F. ; Terzić, T. ; Tescaro, D. ; Teshima, M. ; Thaele, J. ; Tibolla, O. ; Torres, D. F. ; Toyama, T. ; Treves, A. ; Uellenbeck, M. ; Vogler, P. ; Wagner, R. M. ; Zandanel, F. ; Zanin, R. ; Balmaverde, B. ; Kataoka, Jun ; Rekola, R. ; Takahashi, Y. / Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy γ-rays. In: Astronomy and Astrophysics. 2014 ; Vol. 564.
    @article{6e438f916bbd42e6a1d8bca25b4a9ec8,
    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.",
    keywords = "Galaxies: active, Galaxies: individual: NGC 1275, Galaxies: jets, Gamma rays: galaxies",
    author = "J. Aleksić 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. Godinović 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 and M. Palatiello and D. Paneque and R. Paoletti and Paredes, {J. M.} and X. Paredes-Fortuny and S. Partini and M. Persic and F. Prada and {Prada Moroni}, {P. G.} and E. Prandini and S. Preziuso and I. Puljak and R. Reinthal and W. Rhode and M. Rib{\'o} and J. Rico and {Rodriguez Garcia}, J. and S. R{\"u}gamer and A. Saggion and T. Saito and K. Saito and M. Salvati and K. Satalecka and V. Scalzotto and V. Scapin and C. Schultz and T. Schweizer and Shore, {S. N.} and A. Sillanp{\"a}{\"a} and J. Sitarek and I. Snidaric and D. Sobczynska and F. Spanier and V. Stamatescu and A. Stamerra and T. Steinbring and J. Storz and S. Sun and T. Surić and L. Takalo and F. Tavecchio and T. Terzić and D. Tescaro and M. Teshima and J. Thaele and O. Tibolla and Torres, {D. F.} and T. Toyama and A. Treves and M. Uellenbeck and P. Vogler and Wagner, {R. M.} and F. Zandanel and R. Zanin and B. Balmaverde and Jun Kataoka and R. Rekola and Y. Takahashi",
    year = "2014",
    doi = "10.1051/0004-6361/201322951",
    language = "English",
    volume = "564",
    journal = "Astronomy and Astrophysics",
    issn = "0004-6361",
    publisher = "EDP Sciences",

    }

    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.

    AU - Palatiello, M.

    AU - Paneque, D.

    AU - Paoletti, R.

    AU - Paredes, J. M.

    AU - Paredes-Fortuny, X.

    AU - Partini, S.

    AU - Persic, M.

    AU - Prada, F.

    AU - Prada Moroni, P. G.

    AU - Prandini, E.

    AU - Preziuso, S.

    AU - Puljak, I.

    AU - Reinthal, R.

    AU - Rhode, W.

    AU - Ribó, M.

    AU - Rico, J.

    AU - Rodriguez Garcia, J.

    AU - Rügamer, S.

    AU - Saggion, A.

    AU - Saito, T.

    AU - Saito, K.

    AU - Salvati, M.

    AU - Satalecka, K.

    AU - Scalzotto, V.

    AU - Scapin, V.

    AU - Schultz, C.

    AU - Schweizer, T.

    AU - Shore, S. N.

    AU - Sillanpää, A.

    AU - Sitarek, J.

    AU - Snidaric, I.

    AU - Sobczynska, D.

    AU - Spanier, F.

    AU - Stamatescu, V.

    AU - Stamerra, A.

    AU - Steinbring, T.

    AU - Storz, J.

    AU - Sun, S.

    AU - Surić, T.

    AU - Takalo, L.

    AU - Tavecchio, F.

    AU - Terzić, T.

    AU - Tescaro, D.

    AU - Teshima, M.

    AU - Thaele, J.

    AU - Tibolla, O.

    AU - Torres, D. F.

    AU - Toyama, T.

    AU - Treves, A.

    AU - Uellenbeck, M.

    AU - Vogler, P.

    AU - Wagner, R. M.

    AU - Zandanel, F.

    AU - Zanin, R.

    AU - Balmaverde, B.

    AU - Kataoka, Jun

    AU - Rekola, R.

    AU - Takahashi, Y.

    PY - 2014

    Y1 - 2014

    N2 - Aims. The radio galaxy NGC≠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≠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≠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.

    AB - Aims. The radio galaxy NGC≠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≠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≠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.

    KW - Galaxies: active

    KW - Galaxies: individual: NGC 1275

    KW - Galaxies: jets

    KW - Gamma rays: galaxies

    UR - http://www.scopus.com/inward/record.url?scp=84897075513&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=84897075513&partnerID=8YFLogxK

    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 -