Fermi/large area telescope discovery of gamma-ray emission from a relativistic jet in the narrow-line quasar pmn j0948+0022

A. A. Abdo, M. Ackermann, M. Ajello, M. Axelsson, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, M. Battelino, B. M. Baughman, K. Bechtol, R. Bellazzini, E. D. Bloom, E. Bonamente, A. W. Borgland, J. Bregeon, A. Brez, M. Brigida, P. Bruel, G. A. Caliandro & 151 others R. A. Cameron, P. A. Caraveo, J. M. Casandjian, E. Cavazzuti, C. Cecchi, A. Chekhtman, C. C. Cheung, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, W. Collmar, J. Conrad, L. Costamante, C. D. Dermer, A. De Angelis, F. De Palma, S. W. Digel, E. Do Couto E Silva, P. S. Drell, R. Dubois, D. Dumora, C. Farnier, C. Favuzzi, W. B. Focke, L. Foschini, M. Frailis, L. Fuhrmann, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, N. Gehrels, S. Germani, B. Giebels, N. Giglietto, F. Giordano, M. Giroletti, T. Glanzman, I. A. Grenier, M. H. Grondin, J. E. Grove, L. Guillemot, S. Guiriec, Y. Hanabata, A. K. Harding, R. C. Hartman, M. Hayashida, E. Hays, R. E. Hughes, G. Jóhannesson, A. S. Johnson, R. P. Johnson, W. N. Johnson, T. Kamae, H. Katagiri, Jun Kataoka, M. Kerr, J. Knödlseder, F. Kuehn, M. Kuss, J. Lande, L. Latronico, M. Lemoine-Goumard, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, G. M. Madejski, A. Makeev, W. Max-Moerbeck, M. N. Mazziotta, W. McConville, J. E. McEnery, C. Meurer, P. F. Michelson, W. Mitthumsiri, T. Mizuno, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, P. L. Nolan, J. P. Norris, E. Nuss, T. Ohsugi, N. Omodei, E. Orlando, J. F. Ormes, D. Paneque, J. H. Panetta, D. Parent, V. Pavlidou, T. J. Pearson, M. Pepe, M. Pesce-Rollins, F. Piron, T. A. Porter, S. Rainò, R. Rando, M. Razzano, A. Readhead, A. Reimer, O. Reimer, T. Reposeur, J. L. Richards, S. Ritz, A. Y. Rodriguez, R. W. Romani, F. Ryde, H. F W Sadrozinski, R. Sambruna, D. Sanchez, A. Sander, P. M Saz Parkinson, J. D. Scargle, T. L. Schalk, C. Sgrò, D. A. Smith, G. Spandre, P. Spinelli, J. L. Starck, M. Stevenson, M. S. Strickman, D. J. Suson, G. Tagliaferri, H. Takahashi, T. Tanaka, J. G. Thayer, D. J. Thompson, L. Tibaldo, O. Tibolla, D. F. Torres, G. Tosti, A. Tramacere, Y. Uchiyama, T. L. Usher, N. Vilchez, V. Vitale, A. P. Waite, B. L. Winer, K. S. Wood, T. Ylinen, J. A. Zensus, M. Ziegler, G. Ghisellini, L. Maraschi, F. Tavecchio, E. Angelakis

    Research output: Contribution to journalArticle

    120 Citations (Scopus)

    Abstract

    We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy γ-ray emission from the peculiar quasar PMN J0948+0022 (z = 0.5846). The optical spectrum of this object exhibits rather narrow Hβ (FWHM(Hβ) 1500 km s-1), weak forbidden lines, and is therefore classified as a narrow-line type I quasar. This class of objects is thought to have relatively small black hole mass and to accrete at a high Eddington ratio. The radio loudness and variability of the compact radio core indicate the presence of a relativistic jet. Quasi-simultaneous radio/optical/X-ray and γ-ray observations are presented. Both radio and γ-ray emissions (observed over five months) are strongly variable. The simultaneous optical and X-ray data from Swift show a blue continuum attributed to the accretion disk and a hard X-ray spectrum attributed to the jet. The resulting broadband spectral energy distribution (SED) and, in particular, the γ-ray spectrum measured by Fermi are similar to those of more powerful Flat-Spectrum Radio Quasars (FSRQs). A comparison of the radio and γ-ray characteristics of PMN J0948+0022 with the other blazars detected by LAT shows that this source has a relatively low radio and γ-ray power with respect to other FSRQs. The physical parameters obtained from modeling the SED also fall at the low power end of the FSRQ parameter region discussed in Celotti & Ghisellini. We suggest that the similarity of the SED of PMN J0948+0022 to that of more massive and more powerful quasars can be understood in a scenario in which the SED properties depend on the Eddington ratio rather than on the absolute power.

    Original languageEnglish
    Pages (from-to)976-984
    Number of pages9
    JournalAstrophysical Journal
    Volume699
    Issue number2
    DOIs
    Publication statusPublished - 2009

    Fingerprint

    quasars
    rays
    gamma rays
    telescopes
    radio
    spectral energy distribution
    radio spectra
    energy
    Fermi Gamma-ray Space Telescope
    blazars
    x rays
    loudness
    distribution (property)
    accretion disks
    optical spectrum
    continuums
    broadband
    accretion
    distribution
    modeling

    Keywords

    • Galaxies: active
    • Gamma rays: observations

    ASJC Scopus subject areas

    • Space and Planetary Science
    • Astronomy and Astrophysics

    Cite this

    Abdo, A. A., Ackermann, M., Ajello, M., Axelsson, M., Baldini, L., Ballet, J., ... Angelakis, E. (2009). Fermi/large area telescope discovery of gamma-ray emission from a relativistic jet in the narrow-line quasar pmn j0948+0022. Astrophysical Journal, 699(2), 976-984. https://doi.org/10.1088/0004-637X/699/2/976

    Fermi/large area telescope discovery of gamma-ray emission from a relativistic jet in the narrow-line quasar pmn j0948+0022. / Abdo, A. A.; Ackermann, M.; Ajello, M.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Battelino, M.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Collmar, W.; Conrad, J.; Costamante, L.; Dermer, C. D.; De Angelis, A.; De Palma, F.; Digel, S. W.; Silva, E. Do Couto E; Drell, P. S.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Focke, W. B.; Foschini, L.; Frailis, M.; Fuhrmann, L.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Grenier, I. A.; Grondin, M. H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Harding, A. K.; Hartman, R. C.; Hayashida, M.; Hays, E.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, R. P.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, Jun; Kerr, M.; Knödlseder, J.; Kuehn, F.; Kuss, M.; Lande, J.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Max-Moerbeck, W.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Pavlidou, V.; Pearson, T. J.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Readhead, A.; Reimer, A.; Reimer, O.; Reposeur, T.; Richards, J. L.; Ritz, S.; Rodriguez, A. Y.; Romani, R. W.; Ryde, F.; Sadrozinski, H. F W; Sambruna, R.; Sanchez, D.; Sander, A.; Parkinson, P. M Saz; Scargle, J. D.; Schalk, T. L.; Sgrò, C.; Smith, D. A.; Spandre, G.; Spinelli, P.; Starck, J. L.; Stevenson, M.; Strickman, M. S.; Suson, D. J.; Tagliaferri, G.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vilchez, N.; Vitale, V.; Waite, A. P.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Zensus, J. A.; Ziegler, M.; Ghisellini, G.; Maraschi, L.; Tavecchio, F.; Angelakis, E.

    In: Astrophysical Journal, Vol. 699, No. 2, 2009, p. 976-984.

    Research output: Contribution to journalArticle

    Abdo, AA, Ackermann, M, Ajello, M, Axelsson, M, Baldini, L, Ballet, J, Barbiellini, G, Bastieri, D, Battelino, M, Baughman, BM, Bechtol, K, Bellazzini, R, Bloom, ED, Bonamente, E, Borgland, AW, Bregeon, J, Brez, A, Brigida, M, Bruel, P, Caliandro, GA, Cameron, RA, Caraveo, PA, Casandjian, JM, Cavazzuti, E, Cecchi, C, Chekhtman, A, Cheung, CC, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, Collmar, W, Conrad, J, Costamante, L, Dermer, CD, De Angelis, A, De Palma, F, Digel, SW, Silva, EDCE, Drell, PS, Dubois, R, Dumora, D, Farnier, C, Favuzzi, C, Focke, WB, Foschini, L, Frailis, M, Fuhrmann, L, Fukazawa, Y, Funk, S, Fusco, P, Gargano, F, Gehrels, N, Germani, S, Giebels, B, Giglietto, N, Giordano, F, Giroletti, M, Glanzman, T, Grenier, IA, Grondin, MH, Grove, JE, Guillemot, L, Guiriec, S, Hanabata, Y, Harding, AK, Hartman, RC, Hayashida, M, Hays, E, Hughes, RE, Jóhannesson, G, Johnson, AS, Johnson, RP, Johnson, WN, Kamae, T, Katagiri, H, Kataoka, J, Kerr, M, Knödlseder, J, Kuehn, F, Kuss, M, Lande, J, Latronico, L, Lemoine-Goumard, M, Longo, F, Loparco, F, Lott, B, Lovellette, MN, Lubrano, P, Madejski, GM, Makeev, A, Max-Moerbeck, W, Mazziotta, MN, McConville, W, McEnery, JE, Meurer, C, Michelson, PF, Mitthumsiri, W, Mizuno, T, Monte, C, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nolan, PL, Norris, JP, Nuss, E, Ohsugi, T, Omodei, N, Orlando, E, Ormes, JF, Paneque, D, Panetta, JH, Parent, D, Pavlidou, V, Pearson, TJ, Pepe, M, Pesce-Rollins, M, Piron, F, Porter, TA, Rainò, S, Rando, R, Razzano, M, Readhead, A, Reimer, A, Reimer, O, Reposeur, T, Richards, JL, Ritz, S, Rodriguez, AY, Romani, RW, Ryde, F, Sadrozinski, HFW, Sambruna, R, Sanchez, D, Sander, A, Parkinson, PMS, Scargle, JD, Schalk, TL, Sgrò, C, Smith, DA, Spandre, G, Spinelli, P, Starck, JL, Stevenson, M, Strickman, MS, Suson, DJ, Tagliaferri, G, Takahashi, H, Tanaka, T, Thayer, JG, Thompson, DJ, Tibaldo, L, Tibolla, O, Torres, DF, Tosti, G, Tramacere, A, Uchiyama, Y, Usher, TL, Vilchez, N, Vitale, V, Waite, AP, Winer, BL, Wood, KS, Ylinen, T, Zensus, JA, Ziegler, M, Ghisellini, G, Maraschi, L, Tavecchio, F & Angelakis, E 2009, 'Fermi/large area telescope discovery of gamma-ray emission from a relativistic jet in the narrow-line quasar pmn j0948+0022', Astrophysical Journal, vol. 699, no. 2, pp. 976-984. https://doi.org/10.1088/0004-637X/699/2/976
    Abdo, A. A. ; Ackermann, M. ; Ajello, M. ; Axelsson, M. ; Baldini, L. ; Ballet, J. ; Barbiellini, G. ; Bastieri, D. ; Battelino, M. ; Baughman, B. M. ; Bechtol, K. ; Bellazzini, R. ; Bloom, E. D. ; Bonamente, E. ; Borgland, A. W. ; Bregeon, J. ; Brez, A. ; Brigida, M. ; Bruel, P. ; Caliandro, G. A. ; Cameron, R. A. ; Caraveo, P. A. ; Casandjian, J. M. ; Cavazzuti, E. ; Cecchi, C. ; Chekhtman, A. ; Cheung, C. C. ; Chiang, J. ; Ciprini, S. ; Claus, R. ; Cohen-Tanugi, J. ; Collmar, W. ; Conrad, J. ; Costamante, L. ; Dermer, C. D. ; De Angelis, A. ; De Palma, F. ; Digel, S. W. ; Silva, E. Do Couto E ; Drell, P. S. ; Dubois, R. ; Dumora, D. ; Farnier, C. ; Favuzzi, C. ; Focke, W. B. ; Foschini, L. ; Frailis, M. ; Fuhrmann, L. ; Fukazawa, Y. ; Funk, S. ; Fusco, P. ; Gargano, F. ; Gehrels, N. ; Germani, S. ; Giebels, B. ; Giglietto, N. ; Giordano, F. ; Giroletti, M. ; Glanzman, T. ; Grenier, I. A. ; Grondin, M. H. ; Grove, J. E. ; Guillemot, L. ; Guiriec, S. ; Hanabata, Y. ; Harding, A. K. ; Hartman, R. C. ; Hayashida, M. ; Hays, E. ; Hughes, R. E. ; Jóhannesson, G. ; Johnson, A. S. ; Johnson, R. P. ; Johnson, W. N. ; Kamae, T. ; Katagiri, H. ; Kataoka, Jun ; Kerr, M. ; Knödlseder, J. ; Kuehn, F. ; Kuss, M. ; Lande, J. ; Latronico, L. ; Lemoine-Goumard, M. ; Longo, F. ; Loparco, F. ; Lott, B. ; Lovellette, M. N. ; Lubrano, P. ; Madejski, G. M. ; Makeev, A. ; Max-Moerbeck, W. ; Mazziotta, M. N. ; McConville, W. ; McEnery, J. E. ; Meurer, C. ; Michelson, P. F. ; Mitthumsiri, W. ; Mizuno, T. ; Monte, C. ; Monzani, M. E. ; Morselli, A. ; Moskalenko, I. V. ; Murgia, S. ; Nolan, P. L. ; Norris, J. P. ; Nuss, E. ; Ohsugi, T. ; Omodei, N. ; Orlando, E. ; Ormes, J. F. ; Paneque, D. ; Panetta, J. H. ; Parent, D. ; Pavlidou, V. ; Pearson, T. J. ; Pepe, M. ; Pesce-Rollins, M. ; Piron, F. ; Porter, T. A. ; Rainò, S. ; Rando, R. ; Razzano, M. ; Readhead, A. ; Reimer, A. ; Reimer, O. ; Reposeur, T. ; Richards, J. L. ; Ritz, S. ; Rodriguez, A. Y. ; Romani, R. W. ; Ryde, F. ; Sadrozinski, H. F W ; Sambruna, R. ; Sanchez, D. ; Sander, A. ; Parkinson, P. M Saz ; Scargle, J. D. ; Schalk, T. L. ; Sgrò, C. ; Smith, D. A. ; Spandre, G. ; Spinelli, P. ; Starck, J. L. ; Stevenson, M. ; Strickman, M. S. ; Suson, D. J. ; Tagliaferri, G. ; Takahashi, H. ; Tanaka, T. ; Thayer, J. G. ; Thompson, D. J. ; Tibaldo, L. ; Tibolla, O. ; Torres, D. F. ; Tosti, G. ; Tramacere, A. ; Uchiyama, Y. ; Usher, T. L. ; Vilchez, N. ; Vitale, V. ; Waite, A. P. ; Winer, B. L. ; Wood, K. S. ; Ylinen, T. ; Zensus, J. A. ; Ziegler, M. ; Ghisellini, G. ; Maraschi, L. ; Tavecchio, F. ; Angelakis, E. / Fermi/large area telescope discovery of gamma-ray emission from a relativistic jet in the narrow-line quasar pmn j0948+0022. In: Astrophysical Journal. 2009 ; Vol. 699, No. 2. pp. 976-984.
    @article{9ab096eda88841fb9555d4429058ce22,
    title = "Fermi/large area telescope discovery of gamma-ray emission from a relativistic jet in the narrow-line quasar pmn j0948+0022",
    abstract = "We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy γ-ray emission from the peculiar quasar PMN J0948+0022 (z = 0.5846). The optical spectrum of this object exhibits rather narrow Hβ (FWHM(Hβ) 1500 km s-1), weak forbidden lines, and is therefore classified as a narrow-line type I quasar. This class of objects is thought to have relatively small black hole mass and to accrete at a high Eddington ratio. The radio loudness and variability of the compact radio core indicate the presence of a relativistic jet. Quasi-simultaneous radio/optical/X-ray and γ-ray observations are presented. Both radio and γ-ray emissions (observed over five months) are strongly variable. The simultaneous optical and X-ray data from Swift show a blue continuum attributed to the accretion disk and a hard X-ray spectrum attributed to the jet. The resulting broadband spectral energy distribution (SED) and, in particular, the γ-ray spectrum measured by Fermi are similar to those of more powerful Flat-Spectrum Radio Quasars (FSRQs). A comparison of the radio and γ-ray characteristics of PMN J0948+0022 with the other blazars detected by LAT shows that this source has a relatively low radio and γ-ray power with respect to other FSRQs. The physical parameters obtained from modeling the SED also fall at the low power end of the FSRQ parameter region discussed in Celotti & Ghisellini. We suggest that the similarity of the SED of PMN J0948+0022 to that of more massive and more powerful quasars can be understood in a scenario in which the SED properties depend on the Eddington ratio rather than on the absolute power.",
    keywords = "Galaxies: active, Gamma rays: observations",
    author = "Abdo, {A. A.} and M. Ackermann and M. Ajello and M. Axelsson and L. Baldini and J. Ballet and G. Barbiellini and D. Bastieri and M. Battelino and Baughman, {B. M.} and K. Bechtol and R. Bellazzini and Bloom, {E. D.} and E. Bonamente and Borgland, {A. W.} and J. Bregeon and A. Brez and M. Brigida and P. Bruel and Caliandro, {G. A.} and Cameron, {R. A.} and Caraveo, {P. A.} and Casandjian, {J. M.} and E. Cavazzuti and C. Cecchi and A. Chekhtman and Cheung, {C. C.} and J. Chiang and S. Ciprini and R. Claus and J. Cohen-Tanugi and W. Collmar and J. Conrad and L. Costamante and Dermer, {C. D.} and {De Angelis}, A. and {De Palma}, F. and Digel, {S. W.} and Silva, {E. Do Couto E} and Drell, {P. S.} and R. Dubois and D. Dumora and C. Farnier and C. Favuzzi and Focke, {W. B.} and L. Foschini and M. Frailis and L. Fuhrmann and Y. Fukazawa and S. Funk and P. Fusco and F. Gargano and N. Gehrels and S. Germani and B. Giebels and N. Giglietto and F. Giordano and M. Giroletti and T. Glanzman and Grenier, {I. A.} and Grondin, {M. H.} and Grove, {J. E.} and L. Guillemot and S. Guiriec and Y. Hanabata and Harding, {A. K.} and Hartman, {R. C.} and M. Hayashida and E. Hays and Hughes, {R. E.} and G. J{\'o}hannesson and Johnson, {A. S.} and Johnson, {R. P.} and Johnson, {W. N.} and T. Kamae and H. Katagiri and Jun Kataoka and M. Kerr and J. Kn{\"o}dlseder and F. Kuehn and M. Kuss and J. Lande and L. Latronico and M. Lemoine-Goumard and F. Longo and F. Loparco and B. Lott and Lovellette, {M. N.} and P. Lubrano and Madejski, {G. M.} and A. Makeev and W. Max-Moerbeck and Mazziotta, {M. N.} and W. McConville and McEnery, {J. E.} and C. Meurer and Michelson, {P. F.} and W. Mitthumsiri and T. Mizuno and C. Monte and Monzani, {M. E.} and A. Morselli and Moskalenko, {I. V.} and S. Murgia and Nolan, {P. L.} and Norris, {J. P.} and E. Nuss and T. Ohsugi and N. Omodei and E. Orlando and Ormes, {J. F.} and D. Paneque and Panetta, {J. H.} and D. Parent and V. Pavlidou and Pearson, {T. J.} and M. Pepe and M. Pesce-Rollins and F. Piron and Porter, {T. A.} and S. Rain{\`o} and R. Rando and M. Razzano and A. Readhead and A. Reimer and O. Reimer and T. Reposeur and Richards, {J. L.} and S. Ritz and Rodriguez, {A. Y.} and Romani, {R. W.} and F. Ryde and Sadrozinski, {H. F W} and R. Sambruna and D. Sanchez and A. Sander and Parkinson, {P. M Saz} and Scargle, {J. D.} and Schalk, {T. L.} and C. Sgr{\`o} and Smith, {D. A.} and G. Spandre and P. Spinelli and Starck, {J. L.} and M. Stevenson and Strickman, {M. S.} and Suson, {D. J.} and G. Tagliaferri and H. Takahashi and T. Tanaka and Thayer, {J. G.} and Thompson, {D. J.} and L. Tibaldo and O. Tibolla and Torres, {D. F.} and G. Tosti and A. Tramacere and Y. Uchiyama and Usher, {T. L.} and N. Vilchez and V. Vitale and Waite, {A. P.} and Winer, {B. L.} and Wood, {K. S.} and T. Ylinen and Zensus, {J. A.} and M. Ziegler and G. Ghisellini and L. Maraschi and F. Tavecchio and E. Angelakis",
    year = "2009",
    doi = "10.1088/0004-637X/699/2/976",
    language = "English",
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    TY - JOUR

    T1 - Fermi/large area telescope discovery of gamma-ray emission from a relativistic jet in the narrow-line quasar pmn j0948+0022

    AU - Abdo, A. A.

    AU - Ackermann, M.

    AU - Ajello, M.

    AU - Axelsson, M.

    AU - Baldini, L.

    AU - Ballet, J.

    AU - Barbiellini, G.

    AU - Bastieri, D.

    AU - Battelino, M.

    AU - Baughman, B. M.

    AU - Bechtol, K.

    AU - Bellazzini, R.

    AU - Bloom, E. D.

    AU - Bonamente, E.

    AU - Borgland, A. W.

    AU - Bregeon, J.

    AU - Brez, A.

    AU - Brigida, M.

    AU - Bruel, P.

    AU - Caliandro, G. A.

    AU - Cameron, R. A.

    AU - Caraveo, P. A.

    AU - Casandjian, J. M.

    AU - Cavazzuti, E.

    AU - Cecchi, C.

    AU - Chekhtman, A.

    AU - Cheung, C. C.

    AU - Chiang, J.

    AU - Ciprini, S.

    AU - Claus, R.

    AU - Cohen-Tanugi, J.

    AU - Collmar, W.

    AU - Conrad, J.

    AU - Costamante, L.

    AU - Dermer, C. D.

    AU - De Angelis, A.

    AU - De Palma, F.

    AU - Digel, S. W.

    AU - Silva, E. Do Couto E

    AU - Drell, P. S.

    AU - Dubois, R.

    AU - Dumora, D.

    AU - Farnier, C.

    AU - Favuzzi, C.

    AU - Focke, W. B.

    AU - Foschini, L.

    AU - Frailis, M.

    AU - Fuhrmann, L.

    AU - Fukazawa, Y.

    AU - Funk, S.

    AU - Fusco, P.

    AU - Gargano, F.

    AU - Gehrels, N.

    AU - Germani, S.

    AU - Giebels, B.

    AU - Giglietto, N.

    AU - Giordano, F.

    AU - Giroletti, M.

    AU - Glanzman, T.

    AU - Grenier, I. A.

    AU - Grondin, M. H.

    AU - Grove, J. E.

    AU - Guillemot, L.

    AU - Guiriec, S.

    AU - Hanabata, Y.

    AU - Harding, A. K.

    AU - Hartman, R. C.

    AU - Hayashida, M.

    AU - Hays, E.

    AU - Hughes, R. E.

    AU - Jóhannesson, G.

    AU - Johnson, A. S.

    AU - Johnson, R. P.

    AU - Johnson, W. N.

    AU - Kamae, T.

    AU - Katagiri, H.

    AU - Kataoka, Jun

    AU - Kerr, M.

    AU - Knödlseder, J.

    AU - Kuehn, F.

    AU - Kuss, M.

    AU - Lande, J.

    AU - Latronico, L.

    AU - Lemoine-Goumard, M.

    AU - Longo, F.

    AU - Loparco, F.

    AU - Lott, B.

    AU - Lovellette, M. N.

    AU - Lubrano, P.

    AU - Madejski, G. M.

    AU - Makeev, A.

    AU - Max-Moerbeck, W.

    AU - Mazziotta, M. N.

    AU - McConville, W.

    AU - McEnery, J. E.

    AU - Meurer, C.

    AU - Michelson, P. F.

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    PY - 2009

    Y1 - 2009

    N2 - We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy γ-ray emission from the peculiar quasar PMN J0948+0022 (z = 0.5846). The optical spectrum of this object exhibits rather narrow Hβ (FWHM(Hβ) 1500 km s-1), weak forbidden lines, and is therefore classified as a narrow-line type I quasar. This class of objects is thought to have relatively small black hole mass and to accrete at a high Eddington ratio. The radio loudness and variability of the compact radio core indicate the presence of a relativistic jet. Quasi-simultaneous radio/optical/X-ray and γ-ray observations are presented. Both radio and γ-ray emissions (observed over five months) are strongly variable. The simultaneous optical and X-ray data from Swift show a blue continuum attributed to the accretion disk and a hard X-ray spectrum attributed to the jet. The resulting broadband spectral energy distribution (SED) and, in particular, the γ-ray spectrum measured by Fermi are similar to those of more powerful Flat-Spectrum Radio Quasars (FSRQs). A comparison of the radio and γ-ray characteristics of PMN J0948+0022 with the other blazars detected by LAT shows that this source has a relatively low radio and γ-ray power with respect to other FSRQs. The physical parameters obtained from modeling the SED also fall at the low power end of the FSRQ parameter region discussed in Celotti & Ghisellini. We suggest that the similarity of the SED of PMN J0948+0022 to that of more massive and more powerful quasars can be understood in a scenario in which the SED properties depend on the Eddington ratio rather than on the absolute power.

    AB - We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy γ-ray emission from the peculiar quasar PMN J0948+0022 (z = 0.5846). The optical spectrum of this object exhibits rather narrow Hβ (FWHM(Hβ) 1500 km s-1), weak forbidden lines, and is therefore classified as a narrow-line type I quasar. This class of objects is thought to have relatively small black hole mass and to accrete at a high Eddington ratio. The radio loudness and variability of the compact radio core indicate the presence of a relativistic jet. Quasi-simultaneous radio/optical/X-ray and γ-ray observations are presented. Both radio and γ-ray emissions (observed over five months) are strongly variable. The simultaneous optical and X-ray data from Swift show a blue continuum attributed to the accretion disk and a hard X-ray spectrum attributed to the jet. The resulting broadband spectral energy distribution (SED) and, in particular, the γ-ray spectrum measured by Fermi are similar to those of more powerful Flat-Spectrum Radio Quasars (FSRQs). A comparison of the radio and γ-ray characteristics of PMN J0948+0022 with the other blazars detected by LAT shows that this source has a relatively low radio and γ-ray power with respect to other FSRQs. The physical parameters obtained from modeling the SED also fall at the low power end of the FSRQ parameter region discussed in Celotti & Ghisellini. We suggest that the similarity of the SED of PMN J0948+0022 to that of more massive and more powerful quasars can be understood in a scenario in which the SED properties depend on the Eddington ratio rather than on the absolute power.

    KW - Galaxies: active

    KW - Gamma rays: observations

    UR - http://www.scopus.com/inward/record.url?scp=68149178185&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=68149178185&partnerID=8YFLogxK

    U2 - 10.1088/0004-637X/699/2/976

    DO - 10.1088/0004-637X/699/2/976

    M3 - Article

    VL - 699

    SP - 976

    EP - 984

    JO - Astrophysical Journal

    JF - Astrophysical Journal

    SN - 0004-637X

    IS - 2

    ER -