Suzaku observations of luminous quasars

Revealing the nature of high-energy blazar emission in low-level activity states

A. A. Abdo, M. Ackermann, M. Ajello, E. Antolini, L. Baldini, J. Ballet, G. Barbiellini, M. G. Baring, D. Bastieri, K. Bechtol, R. Bellazzini, B. Berenji, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, J. Bregeon, A. Brez, M. Brigida, P. Bruel & 154 others R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, S. Carrigan, J. M. Casandjian, E. Cavazzuti, C. Cecchi, Ö Çelik, A. Chekhtman, A. W. Chen, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, S. Colafrancesco, J. Conrad, S. Cutini, C. D. Dermer, F. De Palma, S. W. Digel, E. Do Couto E Silva, P. S. Drell, R. Dubois, D. Dumora, C. Farnier, C. Favuzzi, S. J. Fegan, E. C. Ferrara, W. B. Focke, M. Frailis, Y. Fukazawa, P. Fusco, F. Gargano, D. Gasparrini, N. Gehrels, B. Giebels, N. Giglietto, P. Giommi, F. Giordano, M. Giroletti, T. Glanzman, G. Godfrey, P. Grandi, I. A. Grenier, L. Guillemot, S. Guiriec, D. Hadasch, A. K. Harding, M. Hayashida, D. Horan, R. E. Hughes, R. Itoh, M. S. Jackson, G. Jóhannesson, A. S. Johnson, W. N. Johnson, T. Kamae, H. Katagiri, Jun Kataoka, N. Kawai, J. Knödlseder, M. Kuss, J. Lande, L. Latronico, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, G. M. Madejski, A. Makeev, M. N. Mazziotta, J. E. McEnery, S. McGlynn, C. Meurer, P. F. Michelson, W. Mitthumsiri, T. Mizuno, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, I. Nestoras, P. L. Nolan, J. P. Norris, E. Nuss, T. Ohsugi, A. Okumura, E. Orlando, J. F. Ormes, M. Ozaki, D. Paneque, J. H. Panetta, D. Parent, V. Pelassa, M. Pepe, M. Pesce-Rollins, F. Piron, T. A. Porter, S. Rainò, R. Rando, M. Razzano, A. Reimer, O. Reimer, L. C. Reyes, A. Y. Rodriguez, M. Roth, F. Ryde, H. F W Sadrozinski, R. Sambruna, A. Sander, R. Sato, C. Sgrò, M. S. Shaw, E. J. Siskind, P. D. Smith, G. Spandre, P. Spinelli, Stawarz, F. W. Stecker, M. S. Strickman, D. J. Suson, H. Takahashi, T. Takahashi, T. Tanaka, J. B. Thayer, J. G. Thayer, D. J. Thompson, O. Tibolla, D. F. Torres, G. Tosti, A. Tramacere, Y. Uchiyama, T. L. Usher, V. Vasileiou, N. Vilchez, M. Villata, V. Vitale, A. Von Kienlin, A. P. Waite, P. Wang, B. L. Winer, K. S. Wood, Z. Yang, T. Ylinen, M. Ziegler, F. Tavecchio, M. Sikora, P. Schady, P. Roming, M. M. Chester, L. Maraschi

    Research output: Contribution to journalArticle

    20 Citations (Scopus)

    Abstract

    We present the results from the Suzaku X-ray observations of five flat-spectrum radio quasars (FSRQs), namely PKS0208-512, Q0827+243, PKS1127-145, PKS1510-089, and 3C454.3. All these sources were additionally monitored simultaneously or quasi-simultaneously by the Fermi satellite in gamma rays and the Swift UVOT in the UV and optical bands, respectively. We constructed their broadband spectra covering the frequency range from 1014Hz up to 1025Hz, and those reveal the nature of high-energy emission of luminous blazars in their low-activity states. The analyzed X-ray spectra are well fitted by a power-law model with photoelectric absorption. In the case of PKS0208-512, PKS1127-145, and 3C454.3, the X-ray continuum showed indication of hardening at low energies. Moreover, when compared with the previous X-ray observations, we see a significantly increasing contribution of low-energy photons to the total X-ray fluxes when the sources are getting fainter. The same behavior can be noted in the Suzaku data alone. A likely explanation involves a variable, flat-spectrum component produced via inverse-Compton emission, plus an additional, possibly steady soft X-ray component prominent when the source gets fainter. This soft X-ray excess is represented either by a steep power-law (photon indices Γ 3-5) or a blackbody-type emission with temperatures kT 0.1-0.2keV. We model the broadband spectra of the five observed FSRQs using synchrotron self-Compton and/or external-Compton radiation models. Our modeling suggests that the difference between the low- and high-activity states in luminous blazars is due to the different total kinetic power of the jet, most likely related to varying bulk Lorentz factor of the outflow within the blazar emission zone.

    Original languageEnglish
    Pages (from-to)835-849
    Number of pages15
    JournalAstrophysical Journal
    Volume716
    Issue number1
    DOIs
    Publication statusPublished - 2010

    Fingerprint

    quasars
    energy
    x rays
    radio spectra
    blazars
    power law
    radio
    broadband
    photons
    hardening
    synchrotrons
    indication
    coverings
    outflow
    frequency ranges
    gamma rays
    continuums
    kinetics
    radiation
    modeling

    Keywords

    • Galaxies: active
    • Galaxies: jets
    • Radiation mechanisms: non-thermal
    • X-rays: galaxies

    ASJC Scopus subject areas

    • Space and Planetary Science
    • Astronomy and Astrophysics

    Cite this

    Abdo, A. A., Ackermann, M., Ajello, M., Antolini, E., Baldini, L., Ballet, J., ... Maraschi, L. (2010). Suzaku observations of luminous quasars: Revealing the nature of high-energy blazar emission in low-level activity states. Astrophysical Journal, 716(1), 835-849. https://doi.org/10.1088/0004-637X/716/1/835

    Suzaku observations of luminous quasars : Revealing the nature of high-energy blazar emission in low-level activity states. / Abdo, A. A.; Ackermann, M.; Ajello, M.; Antolini, E.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö; Chekhtman, A.; Chen, A. W.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Colafrancesco, S.; Conrad, J.; Cutini, S.; Dermer, C. D.; De Palma, F.; Digel, S. W.; Do Couto E Silva, E.; Drell, P. S.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Frailis, M.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grandi, P.; Grenier, I. A.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hayashida, M.; Horan, D.; Hughes, R. E.; Itoh, R.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, Jun; Kawai, N.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Mazziotta, M. N.; McEnery, J. E.; McGlynn, S.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nestoras, I.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reyes, L. C.; Rodriguez, A. Y.; Roth, M.; Ryde, F.; Sadrozinski, H. F W; Sambruna, R.; Sander, A.; Sato, R.; Sgrò, C.; Shaw, M. S.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Stawarz; Stecker, F. W.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibolla, O.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Vilchez, N.; Villata, M.; Vitale, V.; Von Kienlin, A.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ylinen, T.; Ziegler, M.; Tavecchio, F.; Sikora, M.; Schady, P.; Roming, P.; Chester, M. M.; Maraschi, L.

    In: Astrophysical Journal, Vol. 716, No. 1, 2010, p. 835-849.

    Research output: Contribution to journalArticle

    Abdo, AA, Ackermann, M, Ajello, M, Antolini, E, Baldini, L, Ballet, J, Barbiellini, G, Baring, MG, Bastieri, D, Bechtol, K, Bellazzini, R, Berenji, B, Blandford, RD, Bloom, ED, Bonamente, E, Borgland, AW, Bregeon, J, Brez, A, Brigida, M, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Carrigan, S, Casandjian, JM, Cavazzuti, E, Cecchi, C, Çelik, Ö, Chekhtman, A, Chen, AW, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, Colafrancesco, S, Conrad, J, Cutini, S, Dermer, CD, De Palma, F, Digel, SW, Do Couto E Silva, E, Drell, PS, Dubois, R, Dumora, D, Farnier, C, Favuzzi, C, Fegan, SJ, Ferrara, EC, Focke, WB, Frailis, M, Fukazawa, Y, Fusco, P, Gargano, F, Gasparrini, D, Gehrels, N, Giebels, B, Giglietto, N, Giommi, P, Giordano, F, Giroletti, M, Glanzman, T, Godfrey, G, Grandi, P, Grenier, IA, Guillemot, L, Guiriec, S, Hadasch, D, Harding, AK, Hayashida, M, Horan, D, Hughes, RE, Itoh, R, Jackson, MS, Jóhannesson, G, Johnson, AS, Johnson, WN, Kamae, T, Katagiri, H, Kataoka, J, Kawai, N, Knödlseder, J, Kuss, M, Lande, J, Latronico, L, Longo, F, Loparco, F, Lott, B, Lovellette, MN, Lubrano, P, Madejski, GM, Makeev, A, Mazziotta, MN, McEnery, JE, McGlynn, S, Meurer, C, Michelson, PF, Mitthumsiri, W, Mizuno, T, Monte, C, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nestoras, I, Nolan, PL, Norris, JP, Nuss, E, Ohsugi, T, Okumura, A, Orlando, E, Ormes, JF, Ozaki, M, Paneque, D, Panetta, JH, Parent, D, Pelassa, V, Pepe, M, Pesce-Rollins, M, Piron, F, Porter, TA, Rainò, S, Rando, R, Razzano, M, Reimer, A, Reimer, O, Reyes, LC, Rodriguez, AY, Roth, M, Ryde, F, Sadrozinski, HFW, Sambruna, R, Sander, A, Sato, R, Sgrò, C, Shaw, MS, Siskind, EJ, Smith, PD, Spandre, G, Spinelli, P, Stawarz, Stecker, FW, Strickman, MS, Suson, DJ, Takahashi, H, Takahashi, T, Tanaka, T, Thayer, JB, Thayer, JG, Thompson, DJ, Tibolla, O, Torres, DF, Tosti, G, Tramacere, A, Uchiyama, Y, Usher, TL, Vasileiou, V, Vilchez, N, Villata, M, Vitale, V, Von Kienlin, A, Waite, AP, Wang, P, Winer, BL, Wood, KS, Yang, Z, Ylinen, T, Ziegler, M, Tavecchio, F, Sikora, M, Schady, P, Roming, P, Chester, MM & Maraschi, L 2010, 'Suzaku observations of luminous quasars: Revealing the nature of high-energy blazar emission in low-level activity states', Astrophysical Journal, vol. 716, no. 1, pp. 835-849. https://doi.org/10.1088/0004-637X/716/1/835
    Abdo, A. A. ; Ackermann, M. ; Ajello, M. ; Antolini, E. ; Baldini, L. ; Ballet, J. ; Barbiellini, G. ; Baring, M. G. ; Bastieri, D. ; Bechtol, K. ; Bellazzini, R. ; Berenji, B. ; Blandford, R. D. ; Bloom, E. D. ; Bonamente, E. ; Borgland, A. W. ; Bregeon, J. ; Brez, A. ; Brigida, M. ; Bruel, P. ; Buehler, R. ; Buson, S. ; Caliandro, G. A. ; Cameron, R. A. ; Carrigan, S. ; Casandjian, J. M. ; Cavazzuti, E. ; Cecchi, C. ; Çelik, Ö ; Chekhtman, A. ; Chen, A. W. ; Chiang, J. ; Ciprini, S. ; Claus, R. ; Cohen-Tanugi, J. ; Colafrancesco, S. ; Conrad, J. ; Cutini, S. ; Dermer, C. D. ; De Palma, F. ; Digel, S. W. ; Do Couto E Silva, E. ; Drell, P. S. ; Dubois, R. ; Dumora, D. ; Farnier, C. ; Favuzzi, C. ; Fegan, S. J. ; Ferrara, E. C. ; Focke, W. B. ; Frailis, M. ; Fukazawa, Y. ; Fusco, P. ; Gargano, F. ; Gasparrini, D. ; Gehrels, N. ; Giebels, B. ; Giglietto, N. ; Giommi, P. ; Giordano, F. ; Giroletti, M. ; Glanzman, T. ; Godfrey, G. ; Grandi, P. ; Grenier, I. A. ; Guillemot, L. ; Guiriec, S. ; Hadasch, D. ; Harding, A. K. ; Hayashida, M. ; Horan, D. ; Hughes, R. E. ; Itoh, R. ; Jackson, M. S. ; Jóhannesson, G. ; Johnson, A. S. ; Johnson, W. N. ; Kamae, T. ; Katagiri, H. ; Kataoka, Jun ; Kawai, N. ; Knödlseder, J. ; Kuss, M. ; Lande, J. ; Latronico, L. ; Longo, F. ; Loparco, F. ; Lott, B. ; Lovellette, M. N. ; Lubrano, P. ; Madejski, G. M. ; Makeev, A. ; Mazziotta, M. N. ; McEnery, J. E. ; McGlynn, S. ; Meurer, C. ; Michelson, P. F. ; Mitthumsiri, W. ; Mizuno, T. ; Monte, C. ; Monzani, M. E. ; Morselli, A. ; Moskalenko, I. V. ; Murgia, S. ; Nestoras, I. ; Nolan, P. L. ; Norris, J. P. ; Nuss, E. ; Ohsugi, T. ; Okumura, A. ; Orlando, E. ; Ormes, J. F. ; Ozaki, M. ; Paneque, D. ; Panetta, J. H. ; Parent, D. ; Pelassa, V. ; Pepe, M. ; Pesce-Rollins, M. ; Piron, F. ; Porter, T. A. ; Rainò, S. ; Rando, R. ; Razzano, M. ; Reimer, A. ; Reimer, O. ; Reyes, L. C. ; Rodriguez, A. Y. ; Roth, M. ; Ryde, F. ; Sadrozinski, H. F W ; Sambruna, R. ; Sander, A. ; Sato, R. ; Sgrò, C. ; Shaw, M. S. ; Siskind, E. J. ; Smith, P. D. ; Spandre, G. ; Spinelli, P. ; Stawarz ; Stecker, F. W. ; Strickman, M. S. ; Suson, D. J. ; Takahashi, H. ; Takahashi, T. ; Tanaka, T. ; Thayer, J. B. ; Thayer, J. G. ; Thompson, D. J. ; Tibolla, O. ; Torres, D. F. ; Tosti, G. ; Tramacere, A. ; Uchiyama, Y. ; Usher, T. L. ; Vasileiou, V. ; Vilchez, N. ; Villata, M. ; Vitale, V. ; Von Kienlin, A. ; Waite, A. P. ; Wang, P. ; Winer, B. L. ; Wood, K. S. ; Yang, Z. ; Ylinen, T. ; Ziegler, M. ; Tavecchio, F. ; Sikora, M. ; Schady, P. ; Roming, P. ; Chester, M. M. ; Maraschi, L. / Suzaku observations of luminous quasars : Revealing the nature of high-energy blazar emission in low-level activity states. In: Astrophysical Journal. 2010 ; Vol. 716, No. 1. pp. 835-849.
    @article{f07720b4547c4f079033fa048323fc5c,
    title = "Suzaku observations of luminous quasars: Revealing the nature of high-energy blazar emission in low-level activity states",
    abstract = "We present the results from the Suzaku X-ray observations of five flat-spectrum radio quasars (FSRQs), namely PKS0208-512, Q0827+243, PKS1127-145, PKS1510-089, and 3C454.3. All these sources were additionally monitored simultaneously or quasi-simultaneously by the Fermi satellite in gamma rays and the Swift UVOT in the UV and optical bands, respectively. We constructed their broadband spectra covering the frequency range from 1014Hz up to 1025Hz, and those reveal the nature of high-energy emission of luminous blazars in their low-activity states. The analyzed X-ray spectra are well fitted by a power-law model with photoelectric absorption. In the case of PKS0208-512, PKS1127-145, and 3C454.3, the X-ray continuum showed indication of hardening at low energies. Moreover, when compared with the previous X-ray observations, we see a significantly increasing contribution of low-energy photons to the total X-ray fluxes when the sources are getting fainter. The same behavior can be noted in the Suzaku data alone. A likely explanation involves a variable, flat-spectrum component produced via inverse-Compton emission, plus an additional, possibly steady soft X-ray component prominent when the source gets fainter. This soft X-ray excess is represented either by a steep power-law (photon indices Γ 3-5) or a blackbody-type emission with temperatures kT 0.1-0.2keV. We model the broadband spectra of the five observed FSRQs using synchrotron self-Compton and/or external-Compton radiation models. Our modeling suggests that the difference between the low- and high-activity states in luminous blazars is due to the different total kinetic power of the jet, most likely related to varying bulk Lorentz factor of the outflow within the blazar emission zone.",
    keywords = "Galaxies: active, Galaxies: jets, Radiation mechanisms: non-thermal, X-rays: galaxies",
    author = "Abdo, {A. A.} and M. Ackermann and M. Ajello and E. Antolini and L. Baldini and J. Ballet and G. Barbiellini and Baring, {M. G.} and D. Bastieri and K. Bechtol and R. Bellazzini and B. Berenji and Blandford, {R. D.} and Bloom, {E. D.} and E. Bonamente and Borgland, {A. W.} 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 S. Carrigan and Casandjian, {J. M.} and E. Cavazzuti and C. Cecchi and {\"O} {\cC}elik and A. Chekhtman and Chen, {A. W.} and J. Chiang and S. Ciprini and R. Claus and J. Cohen-Tanugi and S. Colafrancesco and J. Conrad and S. Cutini and Dermer, {C. D.} and {De Palma}, F. and Digel, {S. W.} and {Do Couto E Silva}, E. and Drell, {P. S.} and R. Dubois and D. Dumora and C. Farnier and C. Favuzzi and Fegan, {S. J.} and Ferrara, {E. C.} and Focke, {W. B.} and M. Frailis and Y. Fukazawa and P. Fusco and F. Gargano and D. Gasparrini and N. Gehrels and B. Giebels 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 L. Guillemot and S. Guiriec and D. Hadasch and Harding, {A. K.} and M. Hayashida and D. Horan and Hughes, {R. E.} and R. Itoh and Jackson, {M. S.} and G. J{\'o}hannesson and Johnson, {A. S.} and Johnson, {W. N.} and T. Kamae and H. Katagiri and Jun Kataoka and N. Kawai and J. Kn{\"o}dlseder and M. Kuss and J. Lande and L. Latronico and F. Longo and F. Loparco and B. Lott and Lovellette, {M. N.} and P. Lubrano and Madejski, {G. M.} and A. Makeev and Mazziotta, {M. N.} and McEnery, {J. E.} and S. McGlynn 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 I. Nestoras and Nolan, {P. L.} and Norris, {J. P.} and E. Nuss and T. Ohsugi and A. Okumura and E. Orlando and Ormes, {J. F.} and M. Ozaki and D. Paneque and Panetta, {J. H.} and D. Parent and V. Pelassa 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. Reimer and O. Reimer and Reyes, {L. C.} and Rodriguez, {A. Y.} and M. Roth and F. Ryde and Sadrozinski, {H. F W} and R. Sambruna and A. Sander and R. Sato and C. Sgr{\`o} and Shaw, {M. S.} and Siskind, {E. J.} and Smith, {P. D.} and G. Spandre and P. Spinelli and Stawarz and Stecker, {F. W.} and Strickman, {M. S.} and Suson, {D. J.} and H. Takahashi and T. Takahashi and T. Tanaka and Thayer, {J. B.} and Thayer, {J. G.} and Thompson, {D. J.} and O. Tibolla and Torres, {D. F.} and G. Tosti and A. Tramacere and Y. Uchiyama and Usher, {T. L.} and V. Vasileiou and N. Vilchez and M. Villata and V. Vitale and {Von Kienlin}, A. and Waite, {A. P.} and P. Wang and Winer, {B. L.} and Wood, {K. S.} and Z. Yang and T. Ylinen and M. Ziegler and F. Tavecchio and M. Sikora and P. Schady and P. Roming and Chester, {M. M.} and L. Maraschi",
    year = "2010",
    doi = "10.1088/0004-637X/716/1/835",
    language = "English",
    volume = "716",
    pages = "835--849",
    journal = "Astrophysical Journal",
    issn = "0004-637X",
    publisher = "IOP Publishing Ltd.",
    number = "1",

    }

    TY - JOUR

    T1 - Suzaku observations of luminous quasars

    T2 - Revealing the nature of high-energy blazar emission in low-level activity states

    AU - Abdo, A. A.

    AU - Ackermann, M.

    AU - Ajello, M.

    AU - Antolini, E.

    AU - Baldini, L.

    AU - Ballet, J.

    AU - Barbiellini, G.

    AU - Baring, M. G.

    AU - Bastieri, D.

    AU - Bechtol, K.

    AU - Bellazzini, R.

    AU - Berenji, B.

    AU - Blandford, R. D.

    AU - Bloom, E. D.

    AU - Bonamente, E.

    AU - Borgland, A. W.

    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 - Carrigan, S.

    AU - Casandjian, J. M.

    AU - Cavazzuti, E.

    AU - Cecchi, C.

    AU - Çelik, Ö

    AU - Chekhtman, A.

    AU - Chen, A. W.

    AU - Chiang, J.

    AU - Ciprini, S.

    AU - Claus, R.

    AU - Cohen-Tanugi, J.

    AU - Colafrancesco, S.

    AU - Conrad, J.

    AU - Cutini, S.

    AU - Dermer, C. D.

    AU - De Palma, F.

    AU - Digel, S. W.

    AU - Do Couto E Silva, E.

    AU - Drell, P. S.

    AU - Dubois, R.

    AU - Dumora, D.

    AU - Farnier, C.

    AU - Favuzzi, C.

    AU - Fegan, S. J.

    AU - Ferrara, E. C.

    AU - Focke, W. B.

    AU - Frailis, M.

    AU - Fukazawa, Y.

    AU - Fusco, P.

    AU - Gargano, F.

    AU - Gasparrini, D.

    AU - Gehrels, N.

    AU - Giebels, B.

    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 - Guillemot, L.

    AU - Guiriec, S.

    AU - Hadasch, D.

    AU - Harding, A. K.

    AU - Hayashida, M.

    AU - Horan, D.

    AU - Hughes, R. E.

    AU - Itoh, R.

    AU - Jackson, M. S.

    AU - Jóhannesson, G.

    AU - Johnson, A. S.

    AU - Johnson, W. N.

    AU - Kamae, T.

    AU - Katagiri, H.

    AU - Kataoka, Jun

    AU - Kawai, N.

    AU - Knödlseder, J.

    AU - Kuss, M.

    AU - Lande, J.

    AU - Latronico, L.

    AU - Longo, F.

    AU - Loparco, F.

    AU - Lott, B.

    AU - Lovellette, M. N.

    AU - Lubrano, P.

    AU - Madejski, G. M.

    AU - Makeev, A.

    AU - Mazziotta, M. N.

    AU - McEnery, J. E.

    AU - McGlynn, S.

    AU - Meurer, C.

    AU - Michelson, P. F.

    AU - Mitthumsiri, W.

    AU - Mizuno, T.

    AU - Monte, C.

    AU - Monzani, M. E.

    AU - Morselli, A.

    AU - Moskalenko, I. V.

    AU - Murgia, S.

    AU - Nestoras, I.

    AU - Nolan, P. L.

    AU - Norris, J. P.

    AU - Nuss, E.

    AU - Ohsugi, T.

    AU - Okumura, A.

    AU - Orlando, E.

    AU - Ormes, J. F.

    AU - Ozaki, M.

    AU - Paneque, D.

    AU - Panetta, J. H.

    AU - Parent, D.

    AU - Pelassa, V.

    AU - Pepe, M.

    AU - Pesce-Rollins, M.

    AU - Piron, F.

    AU - Porter, T. A.

    AU - Rainò, S.

    AU - Rando, R.

    AU - Razzano, M.

    AU - Reimer, A.

    AU - Reimer, O.

    AU - Reyes, L. C.

    AU - Rodriguez, A. Y.

    AU - Roth, M.

    AU - Ryde, F.

    AU - Sadrozinski, H. F W

    AU - Sambruna, R.

    AU - Sander, A.

    AU - Sato, R.

    AU - Sgrò, C.

    AU - Shaw, M. S.

    AU - Siskind, E. J.

    AU - Smith, P. D.

    AU - Spandre, G.

    AU - Spinelli, P.

    AU - Stawarz,

    AU - Stecker, F. W.

    AU - Strickman, M. S.

    AU - Suson, D. J.

    AU - Takahashi, H.

    AU - Takahashi, T.

    AU - Tanaka, T.

    AU - Thayer, J. B.

    AU - Thayer, J. G.

    AU - Thompson, D. J.

    AU - Tibolla, O.

    AU - Torres, D. F.

    AU - Tosti, G.

    AU - Tramacere, A.

    AU - Uchiyama, Y.

    AU - Usher, T. L.

    AU - Vasileiou, V.

    AU - Vilchez, N.

    AU - Villata, M.

    AU - Vitale, V.

    AU - Von Kienlin, A.

    AU - Waite, A. P.

    AU - Wang, P.

    AU - Winer, B. L.

    AU - Wood, K. S.

    AU - Yang, Z.

    AU - Ylinen, T.

    AU - Ziegler, M.

    AU - Tavecchio, F.

    AU - Sikora, M.

    AU - Schady, P.

    AU - Roming, P.

    AU - Chester, M. M.

    AU - Maraschi, L.

    PY - 2010

    Y1 - 2010

    N2 - We present the results from the Suzaku X-ray observations of five flat-spectrum radio quasars (FSRQs), namely PKS0208-512, Q0827+243, PKS1127-145, PKS1510-089, and 3C454.3. All these sources were additionally monitored simultaneously or quasi-simultaneously by the Fermi satellite in gamma rays and the Swift UVOT in the UV and optical bands, respectively. We constructed their broadband spectra covering the frequency range from 1014Hz up to 1025Hz, and those reveal the nature of high-energy emission of luminous blazars in their low-activity states. The analyzed X-ray spectra are well fitted by a power-law model with photoelectric absorption. In the case of PKS0208-512, PKS1127-145, and 3C454.3, the X-ray continuum showed indication of hardening at low energies. Moreover, when compared with the previous X-ray observations, we see a significantly increasing contribution of low-energy photons to the total X-ray fluxes when the sources are getting fainter. The same behavior can be noted in the Suzaku data alone. A likely explanation involves a variable, flat-spectrum component produced via inverse-Compton emission, plus an additional, possibly steady soft X-ray component prominent when the source gets fainter. This soft X-ray excess is represented either by a steep power-law (photon indices Γ 3-5) or a blackbody-type emission with temperatures kT 0.1-0.2keV. We model the broadband spectra of the five observed FSRQs using synchrotron self-Compton and/or external-Compton radiation models. Our modeling suggests that the difference between the low- and high-activity states in luminous blazars is due to the different total kinetic power of the jet, most likely related to varying bulk Lorentz factor of the outflow within the blazar emission zone.

    AB - We present the results from the Suzaku X-ray observations of five flat-spectrum radio quasars (FSRQs), namely PKS0208-512, Q0827+243, PKS1127-145, PKS1510-089, and 3C454.3. All these sources were additionally monitored simultaneously or quasi-simultaneously by the Fermi satellite in gamma rays and the Swift UVOT in the UV and optical bands, respectively. We constructed their broadband spectra covering the frequency range from 1014Hz up to 1025Hz, and those reveal the nature of high-energy emission of luminous blazars in their low-activity states. The analyzed X-ray spectra are well fitted by a power-law model with photoelectric absorption. In the case of PKS0208-512, PKS1127-145, and 3C454.3, the X-ray continuum showed indication of hardening at low energies. Moreover, when compared with the previous X-ray observations, we see a significantly increasing contribution of low-energy photons to the total X-ray fluxes when the sources are getting fainter. The same behavior can be noted in the Suzaku data alone. A likely explanation involves a variable, flat-spectrum component produced via inverse-Compton emission, plus an additional, possibly steady soft X-ray component prominent when the source gets fainter. This soft X-ray excess is represented either by a steep power-law (photon indices Γ 3-5) or a blackbody-type emission with temperatures kT 0.1-0.2keV. We model the broadband spectra of the five observed FSRQs using synchrotron self-Compton and/or external-Compton radiation models. Our modeling suggests that the difference between the low- and high-activity states in luminous blazars is due to the different total kinetic power of the jet, most likely related to varying bulk Lorentz factor of the outflow within the blazar emission zone.

    KW - Galaxies: active

    KW - Galaxies: jets

    KW - Radiation mechanisms: non-thermal

    KW - X-rays: galaxies

    UR - http://www.scopus.com/inward/record.url?scp=77952974205&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=77952974205&partnerID=8YFLogxK

    U2 - 10.1088/0004-637X/716/1/835

    DO - 10.1088/0004-637X/716/1/835

    M3 - Article

    VL - 716

    SP - 835

    EP - 849

    JO - Astrophysical Journal

    JF - Astrophysical Journal

    SN - 0004-637X

    IS - 1

    ER -