Multifrequency studies of the peculiar QUASAR 4C +21.35 during the 2010 flaring activity

M. Ackermann; M. Ajello; A. Allafort; E. Antolini; G. Barbiellini; D. Bastieri; R. Bellazzini; E. Bissaldi; E. Bonamente; J. Bregeon; M. Brigida; P. Bruel; R. Buehler; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; E. Cavazzuti; C. Cecchi; R. C.G. Chaves; A. Chekhtman; J. Chiang; G. Chiaro; S. Ciprini; R. Claus; J. Cohen-Tanugi; J. Conrad; S. Cutini; F. D'Ammando; F. De Palma; C. D. Dermer; E. Do Couto E Silva; D. Donato; P. S. Drell; C. Favuzzi; J. Finke; W. B. Focke; A. Franckowiak; Y. Fukazawa; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; N. Giglietto; F. Giordano; M. Giroletti; G. Godfrey; I. A. Grenier; S. Guiriec; M. Hayashida; J. W. Hewitt; D. Horan; R. E. Hughes; G. Iafrate; A. S. Johnson; J. Knödlseder; M. Kuss; J. Lande; S. Larsson; L. Latronico; F. Longo; F. Loparco; M. N. Lovellette; P. Lubrano; M. Mayer; M. N. Mazziotta; J. E. McEnery; P. F. Michelson; T. Mizuno; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; R. Nemmen; E. Nuss; T. Ohsugi; M. Orienti; E. Orlando; J. S. Perkins; M. Pesce-Rollins; F. Piron; G. Pivato; T. A. Porter; S. Rainò; M. Razzano; A. Reimer; O. Reimer; A. Schulz; C. Sgrò; E. J. Siskind; G. Spandre; P. Spinelli; null Stawarz; H. Takahashi; T. Takahashi; J. G. Thayer; J. B. Thayer; D. J. Thompson; M. Tinivella

doi:10.1088/0004-637X/786/2/157

Multifrequency studies of the peculiar QUASAR 4C +21.35 during the 2010 flaring activity

M. Ackermann, M. Ajello, A. Allafort, E. Antolini, G. Barbiellini, D. Bastieri, R. Bellazzini, E. Bissaldi, E. Bonamente, J. Bregeon, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, E. Cavazzuti, C. Cecchi, R. C.G. ChavesA. Chekhtman, J. Chiang, G. Chiaro, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, S. Cutini, F. D'Ammando, F. De Palma, C. D. Dermer, E. Do Couto E Silva, D. Donato, P. S. Drell, C. Favuzzi, J. Finke, W. B. Focke, A. Franckowiak, Y. Fukazawa, P. Fusco, F. Gargano, D. Gasparrini, N. Gehrels, N. Giglietto, F. Giordano, M. Giroletti, G. Godfrey, I. A. Grenier, S. Guiriec, M. Hayashida, J. W. Hewitt, D. Horan, R. E. Hughes, G. Iafrate, A. S. Johnson, J. Knödlseder, M. Kuss, J. Lande, S. Larsson, L. Latronico, F. Longo, F. Loparco, M. N. Lovellette, P. Lubrano, M. Mayer, M. N. Mazziotta, J. E. McEnery, P. F. Michelson, T. Mizuno, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, R. Nemmen, E. Nuss, T. Ohsugi, M. Orienti, E. Orlando, J. S. Perkins, M. Pesce-Rollins, F. Piron, G. Pivato, T. A. Porter, S. Rainò, M. Razzano, A. Reimer, O. Reimer, A. Schulz, C. Sgrò, E. J. Siskind, G. Spandre, P. Spinelli, Stawarz, H. Takahashi, T. Takahashi, J. G. Thayer, J. B. Thayer, D. J. Thompson, M. Tinivella

Department of Clinical and Health Psychology

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

32 Citations (Scopus)

Abstract

© 2014. The American Astronomical Society. All rights reserved. Printed in the U.S.A. The discovery of rapidly variable Very High Energy (VHE; E > 100 GeV) γ -ray emission from 4C +21.35 (PKS 1222+216) by MAGIC on 2010 June 17, triggered by the high activity detected by the Fermi Large Area Telescope (LAT) in high energy (HE;E >100 MeV) γ -rays, poses intriguing questions on the location of the γ -ray emitting region in this flat spectrum radio quasar. We present multifrequency data of 4C +21.35 collected from centimeter to VHE during 2010 to investigate the properties of this source and discuss a possible emission model. The first hint of detection at VHE was observed by MAGIC on 2010 May 3, soon after a γ -ray flare detected by Fermi-LAT that peaked on April 29. The same emission mechanism may therefore be responsible for both the HE and VHE emission during the 2010 flaring episodes. Two optical peaks were detected on 2010 April 20 and June 30, close in time but not simultaneous with the two γ -ray peaks, while no clear connection was observed between the X-ray and γ -ray emission. An increasing flux density was observed in radio and mm bands from the beginning of 2009, in accordance with the increasing γ -ray activity observed by Fermi-LAT, and peaking on 2011 January 27 in the mm regime (230 GHz). We model the spectral energy distributions (SEDs) of 4C +21.35 for the two periods of the VHE detection and a quiescent state, using a one-zone model with the emission coming from a very compact region outside the broad line region. The three SEDs can be fit with a combination of synchrotron self-Compton and external Compton emission of seed photons from a dust torus, changing only the electron distribution parameters between the epochs. The fit of the optical/UV part of the spectrum for 2010 April 29 seems to favor an inner disk radius of <six gravitational radii, as one would expect from a prograde-rotating Kerr black hole.

Original language	English
Article number	157
Journal	Astrophysical Journal
Volume	786
Issue number	2
DOIs	https://doi.org/10.1088/0004-637X/786/2/157
Publication status	Published - 10 May 2014

Keywords

Galaxies: active
Gamma rays: general
Quasars: general
Quasars: individual (4C +21.35)
Radiation mechanisms: non-thermal

Access to Document

10.1088/0004-637X/786/2/157

Cite this

Ackermann, M., Ajello, M., Allafort, A., Antolini, E., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bonamente, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cecchi, C., ... Tinivella, M. (2014). Multifrequency studies of the peculiar QUASAR 4C +21.35 during the 2010 flaring activity. Astrophysical Journal, 786(2), [157]. https://doi.org/10.1088/0004-637X/786/2/157

Ackermann, M. ; Ajello, M. ; Allafort, A. ; Antolini, E. ; Barbiellini, G. ; Bastieri, D. ; Bellazzini, R. ; Bissaldi, E. ; Bonamente, E. ; Bregeon, J. ; Brigida, M. ; Bruel, P. ; Buehler, R. ; Buson, S. ; Caliandro, G. A. ; Cameron, R. A. ; Caraveo, P. A. ; Cavazzuti, E. ; Cecchi, C. ; Chaves, R. C.G. ; Chekhtman, A. ; Chiang, J. ; Chiaro, G. ; Ciprini, S. ; Claus, R. ; Cohen-Tanugi, J. ; Conrad, J. ; Cutini, S. ; D'Ammando, F. ; De Palma, F. ; Dermer, C. D. ; Do Couto E Silva, E. ; Donato, D. ; Drell, P. S. ; Favuzzi, C. ; Finke, J. ; Focke, W. B. ; Franckowiak, A. ; Fukazawa, Y. ; Fusco, P. ; Gargano, F. ; Gasparrini, D. ; Gehrels, N. ; Giglietto, N. ; Giordano, F. ; Giroletti, M. ; Godfrey, G. ; Grenier, I. A. ; Guiriec, S. ; Hayashida, M. ; Hewitt, J. W. ; Horan, D. ; Hughes, R. E. ; Iafrate, G. ; Johnson, A. S. ; Knödlseder, J. ; Kuss, M. ; Lande, J. ; Larsson, S. ; Latronico, L. ; Longo, F. ; Loparco, F. ; Lovellette, M. N. ; Lubrano, P. ; Mayer, M. ; Mazziotta, M. N. ; McEnery, J. E. ; Michelson, P. F. ; Mizuno, T. ; Monzani, M. E. ; Morselli, A. ; Moskalenko, I. V. ; Murgia, S. ; Nemmen, R. ; Nuss, E. ; Ohsugi, T. ; Orienti, M. ; Orlando, E. ; Perkins, J. S. ; Pesce-Rollins, M. ; Piron, F. ; Pivato, G. ; Porter, T. A. ; Rainò, S. ; Razzano, M. ; Reimer, A. ; Reimer, O. ; Schulz, A. ; Sgrò, C. ; Siskind, E. J. ; Spandre, G. ; Spinelli, P. ; Stawarz ; Takahashi, H. ; Takahashi, T. ; Thayer, J. G. ; Thayer, J. B. ; Thompson, D. J. ; Tinivella, M. / Multifrequency studies of the peculiar QUASAR 4C +21.35 during the 2010 flaring activity. In: Astrophysical Journal. 2014 ; Vol. 786, No. 2.

@article{be60f47cfd094a3788682f4534ded63c,

title = "Multifrequency studies of the peculiar QUASAR 4C +21.35 during the 2010 flaring activity",

abstract = "{\textcopyright} 2014. The American Astronomical Society. All rights reserved. Printed in the U.S.A. The discovery of rapidly variable Very High Energy (VHE; E > 100 GeV) γ -ray emission from 4C +21.35 (PKS 1222+216) by MAGIC on 2010 June 17, triggered by the high activity detected by the Fermi Large Area Telescope (LAT) in high energy (HE;E >100 MeV) γ -rays, poses intriguing questions on the location of the γ -ray emitting region in this flat spectrum radio quasar. We present multifrequency data of 4C +21.35 collected from centimeter to VHE during 2010 to investigate the properties of this source and discuss a possible emission model. The first hint of detection at VHE was observed by MAGIC on 2010 May 3, soon after a γ -ray flare detected by Fermi-LAT that peaked on April 29. The same emission mechanism may therefore be responsible for both the HE and VHE emission during the 2010 flaring episodes. Two optical peaks were detected on 2010 April 20 and June 30, close in time but not simultaneous with the two γ -ray peaks, while no clear connection was observed between the X-ray and γ -ray emission. An increasing flux density was observed in radio and mm bands from the beginning of 2009, in accordance with the increasing γ -ray activity observed by Fermi-LAT, and peaking on 2011 January 27 in the mm regime (230 GHz). We model the spectral energy distributions (SEDs) of 4C +21.35 for the two periods of the VHE detection and a quiescent state, using a one-zone model with the emission coming from a very compact region outside the broad line region. The three SEDs can be fit with a combination of synchrotron self-Compton and external Compton emission of seed photons from a dust torus, changing only the electron distribution parameters between the epochs. The fit of the optical/UV part of the spectrum for 2010 April 29 seems to favor an inner disk radius of <six gravitational radii, as one would expect from a prograde-rotating Kerr black hole.",

keywords = "Galaxies: active, Gamma rays: general, Quasars: general, Quasars: individual (4C +21.35), Radiation mechanisms: non-thermal",

author = "M. Ackermann and M. Ajello and A. Allafort and E. Antolini and G. Barbiellini and D. Bastieri and R. Bellazzini and E. Bissaldi and E. Bonamente and J. Bregeon and M. Brigida and P. Bruel and R. Buehler and S. Buson and Caliandro, {G. A.} and Cameron, {R. A.} and Caraveo, {P. A.} and E. Cavazzuti and C. Cecchi and Chaves, {R. C.G.} and A. Chekhtman and J. Chiang and G. Chiaro and S. Ciprini and R. Claus and J. Cohen-Tanugi and J. Conrad and S. Cutini and F. D'Ammando and {De Palma}, F. and Dermer, {C. D.} and {Do Couto E Silva}, E. and D. Donato and Drell, {P. S.} and C. Favuzzi and J. Finke and Focke, {W. B.} and A. Franckowiak and Y. Fukazawa and P. Fusco and F. Gargano and D. Gasparrini and N. Gehrels and N. Giglietto and F. Giordano and M. Giroletti and G. Godfrey and Grenier, {I. A.} and S. Guiriec and M. Hayashida and Hewitt, {J. W.} and D. Horan and Hughes, {R. E.} and G. Iafrate and Johnson, {A. S.} and J. Kn{\"o}dlseder and M. Kuss and J. Lande and S. Larsson and L. Latronico and F. Longo and F. Loparco and Lovellette, {M. N.} and P. Lubrano and M. Mayer and Mazziotta, {M. N.} and McEnery, {J. E.} and Michelson, {P. F.} and T. Mizuno and Monzani, {M. E.} and A. Morselli and Moskalenko, {I. V.} and S. Murgia and R. Nemmen and E. Nuss and T. Ohsugi and M. Orienti and E. Orlando and Perkins, {J. S.} and M. Pesce-Rollins and F. Piron and G. Pivato and Porter, {T. A.} and S. Rain{\`o} and M. Razzano and A. Reimer and O. Reimer and A. Schulz and C. Sgr{\`o} and Siskind, {E. J.} and G. Spandre and P. Spinelli and Stawarz and H. Takahashi and T. Takahashi and Thayer, {J. G.} and Thayer, {J. B.} and Thompson, {D. J.} and M. Tinivella",

year = "2014",

month = may,

day = "10",

doi = "10.1088/0004-637X/786/2/157",

language = "English",

volume = "786",

journal = "Astrophysical Journal",

issn = "0004-637X",

number = "2",

}

Ackermann, M, Ajello, M, Allafort, A, Antolini, E, Barbiellini, G, Bastieri, D, Bellazzini, R, Bissaldi, E, Bonamente, E, Bregeon, J, Brigida, M, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Caraveo, PA, Cavazzuti, E, Cecchi, C, Chaves, RCG, Chekhtman, A, Chiang, J, Chiaro, G, Ciprini, S, Claus, R, Cohen-Tanugi, J, Conrad, J, Cutini, S, D'Ammando, F, De Palma, F, Dermer, CD, Do Couto E Silva, E, Donato, D, Drell, PS, Favuzzi, C, Finke, J, Focke, WB, Franckowiak, A, Fukazawa, Y, Fusco, P, Gargano, F, Gasparrini, D, Gehrels, N, Giglietto, N, Giordano, F, Giroletti, M, Godfrey, G, Grenier, IA, Guiriec, S, Hayashida, M, Hewitt, JW, Horan, D, Hughes, RE, Iafrate, G, Johnson, AS, Knödlseder, J, Kuss, M, Lande, J, Larsson, S, Latronico, L, Longo, F, Loparco, F, Lovellette, MN, Lubrano, P, Mayer, M, Mazziotta, MN, McEnery, JE, Michelson, PF, Mizuno, T, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nemmen, R, Nuss, E, Ohsugi, T, Orienti, M, Orlando, E, Perkins, JS, Pesce-Rollins, M, Piron, F, Pivato, G, Porter, TA, Rainò, S, Razzano, M, Reimer, A, Reimer, O, Schulz, A, Sgrò, C, Siskind, EJ, Spandre, G, Spinelli, P, Stawarz, Takahashi, H, Takahashi, T, Thayer, JG, Thayer, JB, Thompson, DJ & Tinivella, M 2014, 'Multifrequency studies of the peculiar QUASAR 4C +21.35 during the 2010 flaring activity', Astrophysical Journal, vol. 786, no. 2, 157. https://doi.org/10.1088/0004-637X/786/2/157

Multifrequency studies of the peculiar QUASAR 4C +21.35 during the 2010 flaring activity. / Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bonamente, E.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Chaves, R. C.G.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; D'Ammando, F.; De Palma, F.; Dermer, C. D.; Do Couto E Silva, E.; Donato, D.; Drell, P. S.; Favuzzi, C.; Finke, J.; Focke, W. B.; Franckowiak, A.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Giglietto, N.; Giordano, F.; Giroletti, M.; Godfrey, G.; Grenier, I. A.; Guiriec, S.; Hayashida, M.; Hewitt, J. W.; Horan, D.; Hughes, R. E.; Iafrate, G.; Johnson, A. S.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Razzano, M.; Reimer, A.; Reimer, O.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Stawarz; Takahashi, H.; Takahashi, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tinivella, M.

In: Astrophysical Journal, Vol. 786, No. 2, 157, 10.05.2014.

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

TY - JOUR

T1 - Multifrequency studies of the peculiar QUASAR 4C +21.35 during the 2010 flaring activity

AU - Ackermann, M.

AU - Ajello, M.

AU - Allafort, A.

AU - Antolini, E.

AU - Barbiellini, G.

AU - Bastieri, D.

AU - Bellazzini, R.

AU - Bissaldi, E.

AU - Bonamente, E.

AU - Bregeon, J.

AU - Brigida, M.

AU - Bruel, P.

AU - Buehler, R.

AU - Buson, S.

AU - Caliandro, G. A.

AU - Cameron, R. A.

AU - Caraveo, P. A.

AU - Cavazzuti, E.

AU - Cecchi, C.

AU - Chaves, R. C.G.

AU - Chekhtman, A.

AU - Chiang, J.

AU - Chiaro, G.

AU - Ciprini, S.

AU - Claus, R.

AU - Cohen-Tanugi, J.

AU - Conrad, J.

AU - Cutini, S.

AU - D'Ammando, F.

AU - De Palma, F.

AU - Dermer, C. D.

AU - Do Couto E Silva, E.

AU - Donato, D.

AU - Drell, P. S.

AU - Favuzzi, C.

AU - Finke, J.

AU - Focke, W. B.

AU - Franckowiak, A.

AU - Fukazawa, Y.

AU - Fusco, P.

AU - Gargano, F.

AU - Gasparrini, D.

AU - Gehrels, N.

AU - Giglietto, N.

AU - Giordano, F.

AU - Giroletti, M.

AU - Godfrey, G.

AU - Grenier, I. A.

AU - Guiriec, S.

AU - Hayashida, M.

AU - Hewitt, J. W.

AU - Horan, D.

AU - Hughes, R. E.

AU - Iafrate, G.

AU - Johnson, A. S.

AU - Knödlseder, J.

AU - Kuss, M.

AU - Lande, J.

AU - Larsson, S.

AU - Latronico, L.

AU - Longo, F.

AU - Loparco, F.

AU - Lovellette, M. N.

AU - Lubrano, P.

AU - Mayer, M.

AU - Mazziotta, M. N.

AU - McEnery, J. E.

AU - Michelson, P. F.

AU - Mizuno, T.

AU - Monzani, M. E.

AU - Morselli, A.

AU - Moskalenko, I. V.

AU - Murgia, S.

AU - Nemmen, R.

AU - Nuss, E.

AU - Ohsugi, T.

AU - Orienti, M.

AU - Orlando, E.

AU - Perkins, J. S.

AU - Pesce-Rollins, M.

AU - Piron, F.

AU - Pivato, G.

AU - Porter, T. A.

AU - Rainò, S.

AU - Razzano, M.

AU - Reimer, A.

AU - Reimer, O.

AU - Schulz, A.

AU - Sgrò, C.

AU - Siskind, E. J.

AU - Spandre, G.

AU - Spinelli, P.

AU - Stawarz, null

AU - Takahashi, H.

AU - Takahashi, T.

AU - Thayer, J. G.

AU - Thayer, J. B.

AU - Thompson, D. J.

AU - Tinivella, M.

PY - 2014/5/10

Y1 - 2014/5/10

N2 - © 2014. The American Astronomical Society. All rights reserved. Printed in the U.S.A. The discovery of rapidly variable Very High Energy (VHE; E > 100 GeV) γ -ray emission from 4C +21.35 (PKS 1222+216) by MAGIC on 2010 June 17, triggered by the high activity detected by the Fermi Large Area Telescope (LAT) in high energy (HE;E >100 MeV) γ -rays, poses intriguing questions on the location of the γ -ray emitting region in this flat spectrum radio quasar. We present multifrequency data of 4C +21.35 collected from centimeter to VHE during 2010 to investigate the properties of this source and discuss a possible emission model. The first hint of detection at VHE was observed by MAGIC on 2010 May 3, soon after a γ -ray flare detected by Fermi-LAT that peaked on April 29. The same emission mechanism may therefore be responsible for both the HE and VHE emission during the 2010 flaring episodes. Two optical peaks were detected on 2010 April 20 and June 30, close in time but not simultaneous with the two γ -ray peaks, while no clear connection was observed between the X-ray and γ -ray emission. An increasing flux density was observed in radio and mm bands from the beginning of 2009, in accordance with the increasing γ -ray activity observed by Fermi-LAT, and peaking on 2011 January 27 in the mm regime (230 GHz). We model the spectral energy distributions (SEDs) of 4C +21.35 for the two periods of the VHE detection and a quiescent state, using a one-zone model with the emission coming from a very compact region outside the broad line region. The three SEDs can be fit with a combination of synchrotron self-Compton and external Compton emission of seed photons from a dust torus, changing only the electron distribution parameters between the epochs. The fit of the optical/UV part of the spectrum for 2010 April 29 seems to favor an inner disk radius of <six gravitational radii, as one would expect from a prograde-rotating Kerr black hole.

AB - © 2014. The American Astronomical Society. All rights reserved. Printed in the U.S.A. The discovery of rapidly variable Very High Energy (VHE; E > 100 GeV) γ -ray emission from 4C +21.35 (PKS 1222+216) by MAGIC on 2010 June 17, triggered by the high activity detected by the Fermi Large Area Telescope (LAT) in high energy (HE;E >100 MeV) γ -rays, poses intriguing questions on the location of the γ -ray emitting region in this flat spectrum radio quasar. We present multifrequency data of 4C +21.35 collected from centimeter to VHE during 2010 to investigate the properties of this source and discuss a possible emission model. The first hint of detection at VHE was observed by MAGIC on 2010 May 3, soon after a γ -ray flare detected by Fermi-LAT that peaked on April 29. The same emission mechanism may therefore be responsible for both the HE and VHE emission during the 2010 flaring episodes. Two optical peaks were detected on 2010 April 20 and June 30, close in time but not simultaneous with the two γ -ray peaks, while no clear connection was observed between the X-ray and γ -ray emission. An increasing flux density was observed in radio and mm bands from the beginning of 2009, in accordance with the increasing γ -ray activity observed by Fermi-LAT, and peaking on 2011 January 27 in the mm regime (230 GHz). We model the spectral energy distributions (SEDs) of 4C +21.35 for the two periods of the VHE detection and a quiescent state, using a one-zone model with the emission coming from a very compact region outside the broad line region. The three SEDs can be fit with a combination of synchrotron self-Compton and external Compton emission of seed photons from a dust torus, changing only the electron distribution parameters between the epochs. The fit of the optical/UV part of the spectrum for 2010 April 29 seems to favor an inner disk radius of <six gravitational radii, as one would expect from a prograde-rotating Kerr black hole.

KW - Galaxies: active

KW - Gamma rays: general

KW - Quasars: general

KW - Quasars: individual (4C +21.35)

KW - Radiation mechanisms: non-thermal

U2 - 10.1088/0004-637X/786/2/157

DO - 10.1088/0004-637X/786/2/157

M3 - Article

VL - 786

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 157

ER -

Multifrequency studies of the peculiar QUASAR 4C +21.35 during the 2010 flaring activity

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Keywords

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