The radio/gamma-ray connection in active galactic nuclei in the era of the fermi large area telescope

M. Ackermann, M. Ajello, A. Allafort, E. Angelakis, M. Axelsson, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, R. Bellazzini, B. Berenji, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, A. Bouvier, J. Bregeon, A. Brez, M. Brigida, P. Bruel & 127 others R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, A. Cannon, P. A. Caraveo, J. M. Casandjian, E. Cavazzuti, C. Cecchi, E. Charles, A. Chekhtman, C. C. Cheung, S. Ciprini, R. Claus, J. Cohen-Tanugi, S. Cutini, F. De Palma, C. D. Dermer, E. Do Couto E Silva, P. S. Drell, R. Dubois, D. Dumora, L. Escande, C. Favuzzi, S. J. Fegan, W. B. Focke, P. Fortin, M. Frailis, L. Fuhrmann, Y. Fukazawa, P. Fusco, F. Gargano, D. Gasparrini, N. Gehrels, N. Giglietto, P. Giommi, F. Giordano, M. Giroletti, T. Glanzman, G. Godfrey, P. Grandi, I. A. Grenier, S. Guiriec, D. Hadasch, M. Hayashida, E. Hays, S. E. Healey, G. Jóhannesson, A. S. Johnson, T. Kamae, H. Katagiri, Jun Kataoka, J. Knödlseder, M. Kuss, J. Lande, S. H. Lee, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, A. Makeev, W. Max-Moerbeck, M. N. Mazziotta, J. E. McEnery, J. Mehault, P. F. Michelson, T. Mizuno, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, M. Naumann-Godo, S. Nishino, P. L. Nolan, J. P. Norris, E. Nuss, T. Ohsugi, A. Okumura, N. Omodei, E. Orlando, J. F. Ormes, M. Ozaki, D. Paneque, V. Pavlidou, V. Pelassa, M. Pepe, M. Pesce-Rollins, M. Pierbattista, F. Piron, T. A. Porter, S. Rainò, M. Razzano, A. Readhead, A. Reimer, O. Reimer, J. L. Richards, R. W. Romani, H. F W Sadrozinski, J. D. Scargle, C. Sgrò, E. J. Siskind, P. D. Smith, G. Spandre, P. Spinelli, M. S. Strickman, D. J. Suson, H. Takahashi, T. Tanaka, G. B. Taylor, J. G. Thayer, J. B. Thayer, D. J. Thompson, D. F. Torres, G. Tosti, A. Tramacere, E. Troja, J. Vandenbroucke, G. Vianello, V. Vitale, A. P. Waite, P. Wang, B. L. Winer, K. S. Wood, Z. Yang, M. Ziegler

    Research output: Contribution to journalArticle

    94 Citations (Scopus)

    Abstract

    We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose. We use both archival interferometric 8.4GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of <10 -7 for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 × 10-6 to 9.0 × 10-8. Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability < 10-7) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.

    Original languageEnglish
    Article number30
    JournalAstrophysical Journal
    Volume741
    Issue number1
    DOIs
    Publication statusPublished - 2011 Nov 1

    Fingerprint

    active galactic nuclei
    gamma rays
    telescopes
    radio
    energy bands
    radio spectra
    Very Large Array (VLA)
    parabolic reflectors
    energy flux
    statistical analysis
    quasars
    valleys
    energy
    observatories
    observatory
    broadband
    valley

    Keywords

    • BL Lacertae objects: general
    • galaxies: active
    • galaxies: jets
    • gamma rays: galaxies
    • quasars: general
    • radio continuum: galaxies

    ASJC Scopus subject areas

    • Space and Planetary Science
    • Astronomy and Astrophysics

    Cite this

    Ackermann, M., Ajello, M., Allafort, A., Angelakis, E., Axelsson, M., Baldini, L., ... Ziegler, M. (2011). The radio/gamma-ray connection in active galactic nuclei in the era of the fermi large area telescope. Astrophysical Journal, 741(1), [30]. https://doi.org/10.1088/0004-637X/741/1/30

    The radio/gamma-ray connection in active galactic nuclei in the era of the fermi large area telescope. / Ackermann, M.; Ajello, M.; Allafort, A.; Angelakis, E.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Cannon, A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cutini, S.; De Palma, F.; Dermer, C. D.; Do Couto E Silva, E.; Drell, P. S.; Dubois, R.; Dumora, D.; Escande, L.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Frailis, M.; Fuhrmann, L.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grandi, P.; Grenier, I. A.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hays, E.; Healey, S. E.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Katagiri, H.; Kataoka, Jun; Knödlseder, J.; Kuss, M.; Lande, J.; Lee, S. H.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Makeev, A.; Max-Moerbeck, W.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nishino, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Pavlidou, V.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Porter, T. A.; Rainò, S.; Razzano, M.; Readhead, A.; Reimer, A.; Reimer, O.; Richards, J. L.; Romani, R. W.; Sadrozinski, H. F W; Scargle, J. D.; Sgrò, C.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Taylor, G. B.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Torres, D. F.; Tosti, G.; Tramacere, A.; Troja, E.; Vandenbroucke, J.; Vianello, G.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ziegler, M.

    In: Astrophysical Journal, Vol. 741, No. 1, 30, 01.11.2011.

    Research output: Contribution to journalArticle

    Ackermann, M, Ajello, M, Allafort, A, Angelakis, E, Axelsson, M, Baldini, L, Ballet, J, Barbiellini, G, Bastieri, D, Bellazzini, R, Berenji, B, Blandford, RD, Bloom, ED, Bonamente, E, Borgland, AW, Bouvier, A, Bregeon, J, Brez, A, Brigida, M, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Cannon, A, Caraveo, PA, Casandjian, JM, Cavazzuti, E, Cecchi, C, Charles, E, Chekhtman, A, Cheung, CC, Ciprini, S, Claus, R, Cohen-Tanugi, J, Cutini, S, De Palma, F, Dermer, CD, Do Couto E Silva, E, Drell, PS, Dubois, R, Dumora, D, Escande, L, Favuzzi, C, Fegan, SJ, Focke, WB, Fortin, P, Frailis, M, Fuhrmann, L, Fukazawa, Y, Fusco, P, Gargano, F, Gasparrini, D, Gehrels, N, Giglietto, N, Giommi, P, Giordano, F, Giroletti, M, Glanzman, T, Godfrey, G, Grandi, P, Grenier, IA, Guiriec, S, Hadasch, D, Hayashida, M, Hays, E, Healey, SE, Jóhannesson, G, Johnson, AS, Kamae, T, Katagiri, H, Kataoka, J, Knödlseder, J, Kuss, M, Lande, J, Lee, SH, Longo, F, Loparco, F, Lott, B, Lovellette, MN, Lubrano, P, Makeev, A, Max-Moerbeck, W, Mazziotta, MN, McEnery, JE, Mehault, J, Michelson, PF, Mizuno, T, Monte, C, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Naumann-Godo, M, Nishino, S, Nolan, PL, Norris, JP, Nuss, E, Ohsugi, T, Okumura, A, Omodei, N, Orlando, E, Ormes, JF, Ozaki, M, Paneque, D, Pavlidou, V, Pelassa, V, Pepe, M, Pesce-Rollins, M, Pierbattista, M, Piron, F, Porter, TA, Rainò, S, Razzano, M, Readhead, A, Reimer, A, Reimer, O, Richards, JL, Romani, RW, Sadrozinski, HFW, Scargle, JD, Sgrò, C, Siskind, EJ, Smith, PD, Spandre, G, Spinelli, P, Strickman, MS, Suson, DJ, Takahashi, H, Tanaka, T, Taylor, GB, Thayer, JG, Thayer, JB, Thompson, DJ, Torres, DF, Tosti, G, Tramacere, A, Troja, E, Vandenbroucke, J, Vianello, G, Vitale, V, Waite, AP, Wang, P, Winer, BL, Wood, KS, Yang, Z & Ziegler, M 2011, 'The radio/gamma-ray connection in active galactic nuclei in the era of the fermi large area telescope', Astrophysical Journal, vol. 741, no. 1, 30. https://doi.org/10.1088/0004-637X/741/1/30
    Ackermann, M. ; Ajello, M. ; Allafort, A. ; Angelakis, E. ; Axelsson, M. ; Baldini, L. ; Ballet, J. ; Barbiellini, G. ; Bastieri, D. ; Bellazzini, R. ; Berenji, B. ; Blandford, R. D. ; Bloom, E. D. ; Bonamente, E. ; Borgland, A. W. ; Bouvier, A. ; Bregeon, J. ; Brez, A. ; Brigida, M. ; Bruel, P. ; Buehler, R. ; Buson, S. ; Caliandro, G. A. ; Cameron, R. A. ; Cannon, A. ; Caraveo, P. A. ; Casandjian, J. M. ; Cavazzuti, E. ; Cecchi, C. ; Charles, E. ; Chekhtman, A. ; Cheung, C. C. ; Ciprini, S. ; Claus, R. ; Cohen-Tanugi, J. ; Cutini, S. ; De Palma, F. ; Dermer, C. D. ; Do Couto E Silva, E. ; Drell, P. S. ; Dubois, R. ; Dumora, D. ; Escande, L. ; Favuzzi, C. ; Fegan, S. J. ; Focke, W. B. ; Fortin, P. ; Frailis, M. ; Fuhrmann, L. ; Fukazawa, Y. ; Fusco, P. ; Gargano, F. ; Gasparrini, D. ; Gehrels, N. ; Giglietto, N. ; Giommi, P. ; Giordano, F. ; Giroletti, M. ; Glanzman, T. ; Godfrey, G. ; Grandi, P. ; Grenier, I. A. ; Guiriec, S. ; Hadasch, D. ; Hayashida, M. ; Hays, E. ; Healey, S. E. ; Jóhannesson, G. ; Johnson, A. S. ; Kamae, T. ; Katagiri, H. ; Kataoka, Jun ; Knödlseder, J. ; Kuss, M. ; Lande, J. ; Lee, S. H. ; Longo, F. ; Loparco, F. ; Lott, B. ; Lovellette, M. N. ; Lubrano, P. ; Makeev, A. ; Max-Moerbeck, W. ; Mazziotta, M. N. ; McEnery, J. E. ; Mehault, J. ; Michelson, P. F. ; Mizuno, T. ; Monte, C. ; Monzani, M. E. ; Morselli, A. ; Moskalenko, I. V. ; Murgia, S. ; Naumann-Godo, M. ; Nishino, S. ; Nolan, P. L. ; Norris, J. P. ; Nuss, E. ; Ohsugi, T. ; Okumura, A. ; Omodei, N. ; Orlando, E. ; Ormes, J. F. ; Ozaki, M. ; Paneque, D. ; Pavlidou, V. ; Pelassa, V. ; Pepe, M. ; Pesce-Rollins, M. ; Pierbattista, M. ; Piron, F. ; Porter, T. A. ; Rainò, S. ; Razzano, M. ; Readhead, A. ; Reimer, A. ; Reimer, O. ; Richards, J. L. ; Romani, R. W. ; Sadrozinski, H. F W ; Scargle, J. D. ; Sgrò, C. ; Siskind, E. J. ; Smith, P. D. ; Spandre, G. ; Spinelli, P. ; Strickman, M. S. ; Suson, D. J. ; Takahashi, H. ; Tanaka, T. ; Taylor, G. B. ; Thayer, J. G. ; Thayer, J. B. ; Thompson, D. J. ; Torres, D. F. ; Tosti, G. ; Tramacere, A. ; Troja, E. ; Vandenbroucke, J. ; Vianello, G. ; Vitale, V. ; Waite, A. P. ; Wang, P. ; Winer, B. L. ; Wood, K. S. ; Yang, Z. ; Ziegler, M. / The radio/gamma-ray connection in active galactic nuclei in the era of the fermi large area telescope. In: Astrophysical Journal. 2011 ; Vol. 741, No. 1.
    @article{449ffaace6764c9cbfaa68ba7d6c4ca8,
    title = "The radio/gamma-ray connection in active galactic nuclei in the era of the fermi large area telescope",
    abstract = "We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose. We use both archival interferometric 8.4GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of <10 -7 for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 × 10-6 to 9.0 × 10-8. Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability < 10-7) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.",
    keywords = "BL Lacertae objects: general, galaxies: active, galaxies: jets, gamma rays: galaxies, quasars: general, radio continuum: galaxies",
    author = "M. Ackermann and M. Ajello and A. Allafort and E. Angelakis and M. Axelsson and L. Baldini and J. Ballet and G. Barbiellini and D. Bastieri and R. Bellazzini and B. Berenji and Blandford, {R. D.} and Bloom, {E. D.} and E. Bonamente and Borgland, {A. W.} and A. Bouvier and J. Bregeon and A. Brez and M. Brigida and P. Bruel and R. Buehler and S. Buson and Caliandro, {G. A.} and Cameron, {R. A.} and A. Cannon and Caraveo, {P. A.} and Casandjian, {J. M.} and E. Cavazzuti and C. Cecchi and E. Charles and A. Chekhtman and Cheung, {C. C.} and S. Ciprini and R. Claus and J. Cohen-Tanugi and S. Cutini and {De Palma}, F. and Dermer, {C. D.} and {Do Couto E Silva}, E. and Drell, {P. S.} and R. Dubois and D. Dumora and L. Escande and C. Favuzzi and Fegan, {S. J.} and Focke, {W. B.} and P. Fortin and M. Frailis and L. Fuhrmann and Y. Fukazawa and P. Fusco and F. Gargano and D. Gasparrini and N. Gehrels and N. Giglietto and P. Giommi and F. Giordano and M. Giroletti and T. Glanzman and G. Godfrey and P. Grandi and Grenier, {I. A.} and S. Guiriec and D. Hadasch and M. Hayashida and E. Hays and Healey, {S. E.} and G. J{\'o}hannesson and Johnson, {A. S.} and T. Kamae and H. Katagiri and Jun Kataoka and J. Kn{\"o}dlseder and M. Kuss and J. Lande and Lee, {S. H.} and F. Longo and F. Loparco and B. Lott and Lovellette, {M. N.} and P. Lubrano and A. Makeev and W. Max-Moerbeck and Mazziotta, {M. N.} and McEnery, {J. E.} and J. Mehault and Michelson, {P. F.} and T. Mizuno and C. Monte and Monzani, {M. E.} and A. Morselli and Moskalenko, {I. V.} and S. Murgia and M. Naumann-Godo and S. Nishino and Nolan, {P. L.} and Norris, {J. P.} and E. Nuss and T. Ohsugi and A. Okumura and N. Omodei and E. Orlando and Ormes, {J. F.} and M. Ozaki and D. Paneque and V. Pavlidou and V. Pelassa and M. Pepe and M. Pesce-Rollins and M. Pierbattista and F. Piron and Porter, {T. A.} and S. Rain{\`o} and M. Razzano and A. Readhead and A. Reimer and O. Reimer and Richards, {J. L.} and Romani, {R. W.} and Sadrozinski, {H. F W} and Scargle, {J. D.} and C. Sgr{\`o} and Siskind, {E. J.} and Smith, {P. D.} and G. Spandre and P. Spinelli and Strickman, {M. S.} and Suson, {D. J.} and H. Takahashi and T. Tanaka and Taylor, {G. B.} and Thayer, {J. G.} and Thayer, {J. B.} and Thompson, {D. J.} and Torres, {D. F.} and G. Tosti and A. Tramacere and E. Troja and J. Vandenbroucke and G. Vianello and V. Vitale and Waite, {A. P.} and P. Wang and Winer, {B. L.} and Wood, {K. S.} and Z. Yang and M. Ziegler",
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    month = "11",
    day = "1",
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    language = "English",
    volume = "741",
    journal = "Astrophysical Journal",
    issn = "0004-637X",
    publisher = "IOP Publishing Ltd.",
    number = "1",

    }

    TY - JOUR

    T1 - The radio/gamma-ray connection in active galactic nuclei in the era of the fermi large area telescope

    AU - Ackermann, M.

    AU - Ajello, M.

    AU - Allafort, A.

    AU - Angelakis, E.

    AU - Axelsson, M.

    AU - Baldini, L.

    AU - Ballet, J.

    AU - Barbiellini, G.

    AU - Bastieri, D.

    AU - Bellazzini, R.

    AU - Berenji, B.

    AU - Blandford, R. D.

    AU - Bloom, E. D.

    AU - Bonamente, E.

    AU - Borgland, A. W.

    AU - Bouvier, A.

    AU - Bregeon, J.

    AU - Brez, A.

    AU - Brigida, M.

    AU - Bruel, P.

    AU - Buehler, R.

    AU - Buson, S.

    AU - Caliandro, G. A.

    AU - Cameron, R. A.

    AU - Cannon, A.

    AU - Caraveo, P. A.

    AU - Casandjian, J. M.

    AU - Cavazzuti, E.

    AU - Cecchi, C.

    AU - Charles, E.

    AU - Chekhtman, A.

    AU - Cheung, C. C.

    AU - Ciprini, S.

    AU - Claus, R.

    AU - Cohen-Tanugi, J.

    AU - Cutini, S.

    AU - De Palma, F.

    AU - Dermer, C. D.

    AU - Do Couto E Silva, E.

    AU - Drell, P. S.

    AU - Dubois, R.

    AU - Dumora, D.

    AU - Escande, L.

    AU - Favuzzi, C.

    AU - Fegan, S. J.

    AU - Focke, W. B.

    AU - Fortin, P.

    AU - Frailis, M.

    AU - Fuhrmann, L.

    AU - Fukazawa, Y.

    AU - Fusco, P.

    AU - Gargano, F.

    AU - Gasparrini, D.

    AU - Gehrels, N.

    AU - Giglietto, N.

    AU - Giommi, P.

    AU - Giordano, F.

    AU - Giroletti, M.

    AU - Glanzman, T.

    AU - Godfrey, G.

    AU - Grandi, P.

    AU - Grenier, I. A.

    AU - Guiriec, S.

    AU - Hadasch, D.

    AU - Hayashida, M.

    AU - Hays, E.

    AU - Healey, S. E.

    AU - Jóhannesson, G.

    AU - Johnson, A. S.

    AU - Kamae, T.

    AU - Katagiri, H.

    AU - Kataoka, Jun

    AU - Knödlseder, J.

    AU - Kuss, M.

    AU - Lande, J.

    AU - Lee, S. H.

    AU - Longo, F.

    AU - Loparco, F.

    AU - Lott, B.

    AU - Lovellette, M. N.

    AU - Lubrano, P.

    AU - Makeev, A.

    AU - Max-Moerbeck, W.

    AU - Mazziotta, M. N.

    AU - McEnery, J. E.

    AU - Mehault, J.

    AU - Michelson, P. F.

    AU - Mizuno, T.

    AU - Monte, C.

    AU - Monzani, M. E.

    AU - Morselli, A.

    AU - Moskalenko, I. V.

    AU - Murgia, S.

    AU - Naumann-Godo, M.

    AU - Nishino, S.

    AU - Nolan, P. L.

    AU - Norris, J. P.

    AU - Nuss, E.

    AU - Ohsugi, T.

    AU - Okumura, A.

    AU - Omodei, N.

    AU - Orlando, E.

    AU - Ormes, J. F.

    AU - Ozaki, M.

    AU - Paneque, D.

    AU - Pavlidou, V.

    AU - Pelassa, V.

    AU - Pepe, M.

    AU - Pesce-Rollins, M.

    AU - Pierbattista, M.

    AU - Piron, F.

    AU - Porter, T. A.

    AU - Rainò, S.

    AU - Razzano, M.

    AU - Readhead, A.

    AU - Reimer, A.

    AU - Reimer, O.

    AU - Richards, J. L.

    AU - Romani, R. W.

    AU - Sadrozinski, H. F W

    AU - Scargle, J. D.

    AU - Sgrò, C.

    AU - Siskind, E. J.

    AU - Smith, P. D.

    AU - Spandre, G.

    AU - Spinelli, P.

    AU - Strickman, M. S.

    AU - Suson, D. J.

    AU - Takahashi, H.

    AU - Tanaka, T.

    AU - Taylor, G. B.

    AU - Thayer, J. G.

    AU - Thayer, J. B.

    AU - Thompson, D. J.

    AU - Torres, D. F.

    AU - Tosti, G.

    AU - Tramacere, A.

    AU - Troja, E.

    AU - Vandenbroucke, J.

    AU - Vianello, G.

    AU - Vitale, V.

    AU - Waite, A. P.

    AU - Wang, P.

    AU - Winer, B. L.

    AU - Wood, K. S.

    AU - Yang, Z.

    AU - Ziegler, M.

    PY - 2011/11/1

    Y1 - 2011/11/1

    N2 - We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose. We use both archival interferometric 8.4GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of <10 -7 for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 × 10-6 to 9.0 × 10-8. Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability < 10-7) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.

    AB - We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose. We use both archival interferometric 8.4GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of <10 -7 for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 × 10-6 to 9.0 × 10-8. Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability < 10-7) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.

    KW - BL Lacertae objects: general

    KW - galaxies: active

    KW - galaxies: jets

    KW - gamma rays: galaxies

    KW - quasars: general

    KW - radio continuum: galaxies

    UR - http://www.scopus.com/inward/record.url?scp=80155149354&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=80155149354&partnerID=8YFLogxK

    U2 - 10.1088/0004-637X/741/1/30

    DO - 10.1088/0004-637X/741/1/30

    M3 - Article

    VL - 741

    JO - Astrophysical Journal

    JF - Astrophysical Journal

    SN - 0004-637X

    IS - 1

    M1 - 30

    ER -