MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012

J. Aleksić; S. Ansoldi; L. A. Antonelli; P. Antoranz; A. Babic; P. Bangale; U. Barres De Almeida; J. A. Barrio; J. Becerra González; W. Bednarek; E. Bernardini; A. Biland; O. Blanch; S. Bonnefoy; G. Bonnoli; F. Borracci; T. Bretz; E. Carmona; A. Carosi; D. Carreto Fidalgo; P. Colin; E. Colombo; J. L. Contreras; J. Cortina; S. Covino; P. Da Vela; F. Dazzi; A. De Angelis; G. De Caneva; B. De Lotto; C. Delgado Mendez; M. Doert; A. Domínguez; D. Dominis Prester; D. Dorner; M. Doro; S. Einecke; D. Eisenacher; D. Elsaesser; E. Farina; D. Ferenc; M. V. Fonseca; L. Font; K. Frantzen; C. Fruck; R. J. García López; M. Garczarczyk; D. Garrido Terrats; M. Gaug; N. Godinović; A. González Muñoz; S. R. Gozzini; D. Hadasch; M. Hayashida; J. Herrera; A. Herrero; D. Hildebrand; J. Hose; D. Hrupec; W. Idec; V. Kadenius; H. Kellermann; K. Kodani; Y. Konno; J. Krause; H. Kubo; J. Kushida; A. La Barbera; D. Lelas; N. Lewandowska; E. Lindfors; S. Lombardi; M. López; R. López-Coto; A. López-Oramas; E. Lorenz; I. Lozano; M. Makariev; K. Mallot; G. Maneva; N. Mankuzhiyil; K. Mannheim; L. Maraschi; B. Marcote; M. Mariotti; M. Martínez; D. Mazin; U. Menzel; M. Meucci; J. M. Miranda; R. Mirzoyan; A. Moralejo; P. Munar-Adrover; D. Nakajima; A. Niedzwiecki; K. Nilsson; K. Nishijima; K. Noda; N. Nowak; R. Orito

doi:10.1051/0004-6361/201423484

MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012

J. Aleksić, S. Ansoldi, L. A. Antonelli, P. Antoranz, A. Babic, P. Bangale, U. Barres De Almeida, J. A. Barrio, J. Becerra González, W. Bednarek, E. Bernardini, A. Biland, O. Blanch, S. Bonnefoy, G. Bonnoli, F. Borracci, T. Bretz, E. Carmona, A. Carosi, D. Carreto FidalgoP. Colin, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, P. Da Vela, F. Dazzi, A. De Angelis, G. De Caneva, B. De Lotto, C. Delgado Mendez, M. Doert, A. Domínguez, D. Dominis Prester, D. Dorner, M. Doro, S. Einecke, D. Eisenacher, D. Elsaesser, E. Farina, D. Ferenc, M. V. Fonseca, L. Font, K. Frantzen, C. Fruck, R. J. García López, M. Garczarczyk, D. Garrido Terrats, M. Gaug, N. Godinović, A. González Muñoz, S. R. Gozzini, D. Hadasch, M. Hayashida, J. Herrera, A. Herrero, D. Hildebrand, J. Hose, D. Hrupec, W. Idec, V. Kadenius, H. Kellermann, K. Kodani, Y. Konno, J. Krause, H. Kubo, J. Kushida, A. La Barbera, D. Lelas, N. Lewandowska, E. Lindfors, S. Lombardi, M. López, R. López-Coto, A. López-Oramas, E. Lorenz, I. Lozano, M. Makariev, K. Mallot, G. Maneva, N. Mankuzhiyil, K. Mannheim, L. Maraschi, B. Marcote, M. Mariotti, M. Martínez, D. Mazin, U. Menzel, M. Meucci, J. M. Miranda, R. Mirzoyan, A. Moralejo, P. Munar-Adrover, D. Nakajima, A. Niedzwiecki, K. Nilsson, K. Nishijima, K. Noda, N. Nowak, R. Orito

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

63 Citations (Scopus)

Abstract

© 2014 ESO. Aims. Amongst more than fifty blazars detected in very high energy (VHE, E> 100 GeV) γ rays, only three belong to the subclass of flat spectrum radio quasars (FSRQs). The detection of FSRQs in the VHE range is challenging, mainly because of their soft spectra in the GeV-TeV regime. MAGIC observed PKS 1510-089 (z = 0.36) starting 2012 February 3 until April 3 during a high activity state in the high energy (HE, E> 100 MeV) γ-ray band observed by AGILE and Fermi. MAGIC observations result in the detection of a source with significance of 6.0 standard deviations (σ). We study the multi-frequency behaviour of the source at the epoch of MAGIC observation, collecting quasi-simultaneous data at radio and optical (GASP-WEBT and F-Gamma collaborations, REM, Steward, Perkins, Liverpool, OVRO, and VLBA telescopes), X-ray (Swift satellite), and HE γ-ray frequencies. Methods. We study the VHE γ-ray emission, together with the multi-frequency light curves, 43 GHz radio maps, and spectral energy distribution (SED) of the source. The quasi-simultaneous multi-frequency SED from the millimetre radio band to VHE γ rays is modelled with a one-zone inverse Compton model. We study two different origins of the seed photons for the inverse Compton scattering, namely the infrared torus and a slow sheath surrounding the jet around the Very Long Baseline Array (VLBA) core. Results. We find that the VHE γ-ray emission detected from PKS 1510-089 in 2012 February-April agrees with the previous VHE observations of the source from 2009 March-April. We find no statistically significant variability during the MAGIC observations on daily, weekly, or monthly time scales, while the other two known VHE FSRQs (3C 279 and PKS 1222+216) have shown daily scale to sub-hour variability. The γ-ray SED combining AGILE, Fermi and MAGIC data joins smoothly and shows no hint of a break. The multi-frequency light curves suggest a common origin for the millimetre radio and HE γ-ray emission, and the HE γ-ray flaring starts when the new component is ejected from the 43 GHz VLBA core and the studied SED models fit the data well. However, the fast HE γ-ray variability requires that within the modelled large emitting region, more compact regions must exist. We suggest that these observed signatures would be most naturally explained by a turbulent plasma flowing at a relativistic speed down the jet and crossing a standing conical shock.

Original language	English
Article number	A46
Journal	Astronomy and Astrophysics
Volume	569
DOIs	https://doi.org/10.1051/0004-6361/201423484
Publication status	Published - 1 Jan 2014

Keywords

Galaxies: active
Galaxies: jets
Gamma rays: galaxies
Quasars: individual: PKS 1510-089

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Aleksić, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., ... Orito, R. (2014). MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012. Astronomy and Astrophysics, 569, [A46]. https://doi.org/10.1051/0004-6361/201423484

Aleksić, J. ; Ansoldi, S. ; Antonelli, L. A. ; Antoranz, P. ; Babic, A. ; Bangale, P. ; Barres De Almeida, U. ; Barrio, J. A. ; Becerra González, J. ; Bednarek, W. ; Bernardini, E. ; Biland, A. ; Blanch, O. ; Bonnefoy, S. ; Bonnoli, G. ; Borracci, F. ; Bretz, T. ; Carmona, E. ; Carosi, A. ; Carreto Fidalgo, D. ; Colin, P. ; Colombo, E. ; Contreras, J. L. ; Cortina, J. ; Covino, S. ; Da Vela, P. ; Dazzi, F. ; De Angelis, A. ; De Caneva, G. ; De Lotto, B. ; Delgado Mendez, C. ; Doert, M. ; Domínguez, A. ; Dominis Prester, D. ; Dorner, D. ; Doro, M. ; Einecke, S. ; Eisenacher, D. ; Elsaesser, D. ; Farina, E. ; Ferenc, D. ; Fonseca, M. V. ; Font, L. ; Frantzen, K. ; Fruck, C. ; García López, R. J. ; Garczarczyk, M. ; Garrido Terrats, D. ; Gaug, M. ; Godinović, N. ; González Muñoz, A. ; Gozzini, S. R. ; Hadasch, D. ; Hayashida, M. ; Herrera, J. ; Herrero, A. ; Hildebrand, D. ; Hose, J. ; Hrupec, D. ; Idec, W. ; Kadenius, V. ; Kellermann, H. ; Kodani, K. ; Konno, Y. ; Krause, J. ; Kubo, H. ; Kushida, J. ; La Barbera, A. ; Lelas, D. ; Lewandowska, N. ; Lindfors, E. ; Lombardi, S. ; López, M. ; López-Coto, R. ; López-Oramas, A. ; Lorenz, E. ; Lozano, I. ; Makariev, M. ; Mallot, K. ; Maneva, G. ; Mankuzhiyil, N. ; Mannheim, K. ; Maraschi, L. ; Marcote, B. ; Mariotti, M. ; Martínez, M. ; Mazin, D. ; Menzel, U. ; Meucci, M. ; Miranda, J. M. ; Mirzoyan, R. ; Moralejo, A. ; Munar-Adrover, P. ; Nakajima, D. ; Niedzwiecki, A. ; Nilsson, K. ; Nishijima, K. ; Noda, K. ; Nowak, N. ; Orito, R. / MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012. In: Astronomy and Astrophysics. 2014 ; Vol. 569.

@article{08446e9485ca4158a194922e351911fa,

title = "MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012",

abstract = "{\textcopyright} 2014 ESO. Aims. Amongst more than fifty blazars detected in very high energy (VHE, E> 100 GeV) γ rays, only three belong to the subclass of flat spectrum radio quasars (FSRQs). The detection of FSRQs in the VHE range is challenging, mainly because of their soft spectra in the GeV-TeV regime. MAGIC observed PKS 1510-089 (z = 0.36) starting 2012 February 3 until April 3 during a high activity state in the high energy (HE, E> 100 MeV) γ-ray band observed by AGILE and Fermi. MAGIC observations result in the detection of a source with significance of 6.0 standard deviations (σ). We study the multi-frequency behaviour of the source at the epoch of MAGIC observation, collecting quasi-simultaneous data at radio and optical (GASP-WEBT and F-Gamma collaborations, REM, Steward, Perkins, Liverpool, OVRO, and VLBA telescopes), X-ray (Swift satellite), and HE γ-ray frequencies. Methods. We study the VHE γ-ray emission, together with the multi-frequency light curves, 43 GHz radio maps, and spectral energy distribution (SED) of the source. The quasi-simultaneous multi-frequency SED from the millimetre radio band to VHE γ rays is modelled with a one-zone inverse Compton model. We study two different origins of the seed photons for the inverse Compton scattering, namely the infrared torus and a slow sheath surrounding the jet around the Very Long Baseline Array (VLBA) core. Results. We find that the VHE γ-ray emission detected from PKS 1510-089 in 2012 February-April agrees with the previous VHE observations of the source from 2009 March-April. We find no statistically significant variability during the MAGIC observations on daily, weekly, or monthly time scales, while the other two known VHE FSRQs (3C 279 and PKS 1222+216) have shown daily scale to sub-hour variability. The γ-ray SED combining AGILE, Fermi and MAGIC data joins smoothly and shows no hint of a break. The multi-frequency light curves suggest a common origin for the millimetre radio and HE γ-ray emission, and the HE γ-ray flaring starts when the new component is ejected from the 43 GHz VLBA core and the studied SED models fit the data well. However, the fast HE γ-ray variability requires that within the modelled large emitting region, more compact regions must exist. We suggest that these observed signatures would be most naturally explained by a turbulent plasma flowing at a relativistic speed down the jet and crossing a standing conical shock.",

keywords = "Galaxies: active, Galaxies: jets, Gamma rays: galaxies, Quasars: individual: PKS 1510-089",

author = "J. Aleksi{\'c} and S. Ansoldi and Antonelli, {L. A.} and P. Antoranz and A. Babic and P. Bangale and {Barres De Almeida}, U. and Barrio, {J. A.} and {Becerra Gonz{\'a}lez}, J. and W. Bednarek and E. Bernardini and A. Biland and O. Blanch and S. Bonnefoy and G. Bonnoli and F. Borracci and T. Bretz and E. Carmona and A. Carosi and {Carreto Fidalgo}, D. and P. Colin and E. Colombo and Contreras, {J. L.} and J. Cortina and S. Covino and {Da Vela}, P. and F. Dazzi and {De Angelis}, A. and {De Caneva}, G. and {De Lotto}, B. and {Delgado Mendez}, C. and M. Doert and A. Dom{\'i}nguez and {Dominis Prester}, D. and D. Dorner and M. Doro and S. Einecke and D. Eisenacher and D. Elsaesser and E. Farina and D. Ferenc and Fonseca, {M. V.} and L. Font and K. Frantzen and C. Fruck and {Garc{\'i}a L{\'o}pez}, {R. J.} and M. Garczarczyk and {Garrido Terrats}, D. and M. Gaug and N. Godinovi{\'c} and {Gonz{\'a}lez Mu{\~n}oz}, A. and Gozzini, {S. R.} and D. Hadasch and M. Hayashida and J. Herrera and A. Herrero and D. Hildebrand and J. Hose and D. Hrupec and W. Idec and V. Kadenius and H. Kellermann and K. Kodani and Y. Konno and J. Krause and H. Kubo and J. Kushida and {La Barbera}, A. and D. Lelas and N. Lewandowska and E. Lindfors and S. Lombardi and M. L{\'o}pez and R. L{\'o}pez-Coto and A. L{\'o}pez-Oramas and E. Lorenz and I. Lozano and M. Makariev and K. Mallot and G. Maneva and N. Mankuzhiyil and K. Mannheim and L. Maraschi and B. Marcote and M. Mariotti and M. Mart{\'i}nez and D. Mazin and U. Menzel and M. Meucci and Miranda, {J. M.} and R. Mirzoyan and A. Moralejo and P. Munar-Adrover and D. Nakajima and A. Niedzwiecki and K. Nilsson and K. Nishijima and K. Noda and N. Nowak and R. Orito",

year = "2014",

month = jan,

day = "1",

doi = "10.1051/0004-6361/201423484",

language = "English",

volume = "569",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

}

Aleksić, J, Ansoldi, S, Antonelli, LA, Antoranz, P, Babic, A, Bangale, P, Barres De Almeida, U, Barrio, JA, Becerra González, J, Bednarek, W, Bernardini, E, Biland, A, Blanch, O, Bonnefoy, S, Bonnoli, G, Borracci, F, Bretz, T, Carmona, E, Carosi, A, Carreto Fidalgo, D, Colin, P, Colombo, E, Contreras, JL, Cortina, J, Covino, S, Da Vela, P, Dazzi, F, De Angelis, A, De Caneva, G, De Lotto, B, Delgado Mendez, C, Doert, M, Domínguez, A, Dominis Prester, D, Dorner, D, Doro, M, Einecke, S, Eisenacher, D, Elsaesser, D, Farina, E, Ferenc, D, Fonseca, MV, Font, L, Frantzen, K, Fruck, C, García López, RJ, Garczarczyk, M, Garrido Terrats, D, Gaug, M, Godinović, N, González Muñoz, A, Gozzini, SR, Hadasch, D, Hayashida, M, Herrera, J, Herrero, A, Hildebrand, D, Hose, J, Hrupec, D, Idec, W, Kadenius, V, Kellermann, H, Kodani, K, Konno, Y, Krause, J, Kubo, H, Kushida, J, La Barbera, A, Lelas, D, Lewandowska, N, Lindfors, E, Lombardi, S, López, M, López-Coto, R, López-Oramas, A, Lorenz, E, Lozano, I, Makariev, M, Mallot, K, Maneva, G, Mankuzhiyil, N, Mannheim, K, Maraschi, L, Marcote, B, Mariotti, M, Martínez, M, Mazin, D, Menzel, U, Meucci, M, Miranda, JM, Mirzoyan, R, Moralejo, A, Munar-Adrover, P, Nakajima, D, Niedzwiecki, A, Nilsson, K, Nishijima, K, Noda, K, Nowak, N & Orito, R 2014, 'MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012', Astronomy and Astrophysics, vol. 569, A46. https://doi.org/10.1051/0004-6361/201423484

MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012. / Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barres De Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Carreto Fidalgo, D.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; Delgado Mendez, C.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Farina, E.; Ferenc, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Hadasch, D.; Hayashida, M.; Herrera, J.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K.; Noda, K.; Nowak, N.; Orito, R.

In: Astronomy and Astrophysics, Vol. 569, A46, 01.01.2014.

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

TY - JOUR

T1 - MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012

AU - Aleksić, J.

AU - Ansoldi, S.

AU - Antonelli, L. A.

AU - Antoranz, P.

AU - Babic, A.

AU - Bangale, P.

AU - Barres De Almeida, U.

AU - Barrio, J. A.

AU - Becerra González, J.

AU - Bednarek, W.

AU - Bernardini, E.

AU - Biland, A.

AU - Blanch, O.

AU - Bonnefoy, S.

AU - Bonnoli, G.

AU - Borracci, F.

AU - Bretz, T.

AU - Carmona, E.

AU - Carosi, A.

AU - Carreto Fidalgo, D.

AU - Colin, P.

AU - Colombo, E.

AU - Contreras, J. L.

AU - Cortina, J.

AU - Covino, S.

AU - Da Vela, P.

AU - Dazzi, F.

AU - De Angelis, A.

AU - De Caneva, G.

AU - De Lotto, B.

AU - Delgado Mendez, C.

AU - Doert, M.

AU - Domínguez, A.

AU - Dominis Prester, D.

AU - Dorner, D.

AU - Doro, M.

AU - Einecke, S.

AU - Eisenacher, D.

AU - Elsaesser, D.

AU - Farina, E.

AU - Ferenc, D.

AU - Fonseca, M. V.

AU - Font, L.

AU - Frantzen, K.

AU - Fruck, C.

AU - García López, R. J.

AU - Garczarczyk, M.

AU - Garrido Terrats, D.

AU - Gaug, M.

AU - Godinović, N.

AU - González Muñoz, A.

AU - Gozzini, S. R.

AU - Hadasch, D.

AU - Hayashida, M.

AU - Herrera, J.

AU - Herrero, A.

AU - Hildebrand, D.

AU - Hose, J.

AU - Hrupec, D.

AU - Idec, W.

AU - Kadenius, V.

AU - Kellermann, H.

AU - Kodani, K.

AU - Konno, Y.

AU - Krause, J.

AU - Kubo, H.

AU - Kushida, J.

AU - La Barbera, A.

AU - Lelas, D.

AU - Lewandowska, N.

AU - Lindfors, E.

AU - Lombardi, S.

AU - López, M.

AU - López-Coto, R.

AU - López-Oramas, A.

AU - Lorenz, E.

AU - Lozano, I.

AU - Makariev, M.

AU - Mallot, K.

AU - Maneva, G.

AU - Mankuzhiyil, N.

AU - Mannheim, K.

AU - Maraschi, L.

AU - Marcote, B.

AU - Mariotti, M.

AU - Martínez, M.

AU - Mazin, D.

AU - Menzel, U.

AU - Meucci, M.

AU - Miranda, J. M.

AU - Mirzoyan, R.

AU - Moralejo, A.

AU - Munar-Adrover, P.

AU - Nakajima, D.

AU - Niedzwiecki, A.

AU - Nilsson, K.

AU - Nishijima, K.

AU - Noda, K.

AU - Nowak, N.

AU - Orito, R.

PY - 2014/1/1

Y1 - 2014/1/1

N2 - © 2014 ESO. Aims. Amongst more than fifty blazars detected in very high energy (VHE, E> 100 GeV) γ rays, only three belong to the subclass of flat spectrum radio quasars (FSRQs). The detection of FSRQs in the VHE range is challenging, mainly because of their soft spectra in the GeV-TeV regime. MAGIC observed PKS 1510-089 (z = 0.36) starting 2012 February 3 until April 3 during a high activity state in the high energy (HE, E> 100 MeV) γ-ray band observed by AGILE and Fermi. MAGIC observations result in the detection of a source with significance of 6.0 standard deviations (σ). We study the multi-frequency behaviour of the source at the epoch of MAGIC observation, collecting quasi-simultaneous data at radio and optical (GASP-WEBT and F-Gamma collaborations, REM, Steward, Perkins, Liverpool, OVRO, and VLBA telescopes), X-ray (Swift satellite), and HE γ-ray frequencies. Methods. We study the VHE γ-ray emission, together with the multi-frequency light curves, 43 GHz radio maps, and spectral energy distribution (SED) of the source. The quasi-simultaneous multi-frequency SED from the millimetre radio band to VHE γ rays is modelled with a one-zone inverse Compton model. We study two different origins of the seed photons for the inverse Compton scattering, namely the infrared torus and a slow sheath surrounding the jet around the Very Long Baseline Array (VLBA) core. Results. We find that the VHE γ-ray emission detected from PKS 1510-089 in 2012 February-April agrees with the previous VHE observations of the source from 2009 March-April. We find no statistically significant variability during the MAGIC observations on daily, weekly, or monthly time scales, while the other two known VHE FSRQs (3C 279 and PKS 1222+216) have shown daily scale to sub-hour variability. The γ-ray SED combining AGILE, Fermi and MAGIC data joins smoothly and shows no hint of a break. The multi-frequency light curves suggest a common origin for the millimetre radio and HE γ-ray emission, and the HE γ-ray flaring starts when the new component is ejected from the 43 GHz VLBA core and the studied SED models fit the data well. However, the fast HE γ-ray variability requires that within the modelled large emitting region, more compact regions must exist. We suggest that these observed signatures would be most naturally explained by a turbulent plasma flowing at a relativistic speed down the jet and crossing a standing conical shock.

AB - © 2014 ESO. Aims. Amongst more than fifty blazars detected in very high energy (VHE, E> 100 GeV) γ rays, only three belong to the subclass of flat spectrum radio quasars (FSRQs). The detection of FSRQs in the VHE range is challenging, mainly because of their soft spectra in the GeV-TeV regime. MAGIC observed PKS 1510-089 (z = 0.36) starting 2012 February 3 until April 3 during a high activity state in the high energy (HE, E> 100 MeV) γ-ray band observed by AGILE and Fermi. MAGIC observations result in the detection of a source with significance of 6.0 standard deviations (σ). We study the multi-frequency behaviour of the source at the epoch of MAGIC observation, collecting quasi-simultaneous data at radio and optical (GASP-WEBT and F-Gamma collaborations, REM, Steward, Perkins, Liverpool, OVRO, and VLBA telescopes), X-ray (Swift satellite), and HE γ-ray frequencies. Methods. We study the VHE γ-ray emission, together with the multi-frequency light curves, 43 GHz radio maps, and spectral energy distribution (SED) of the source. The quasi-simultaneous multi-frequency SED from the millimetre radio band to VHE γ rays is modelled with a one-zone inverse Compton model. We study two different origins of the seed photons for the inverse Compton scattering, namely the infrared torus and a slow sheath surrounding the jet around the Very Long Baseline Array (VLBA) core. Results. We find that the VHE γ-ray emission detected from PKS 1510-089 in 2012 February-April agrees with the previous VHE observations of the source from 2009 March-April. We find no statistically significant variability during the MAGIC observations on daily, weekly, or monthly time scales, while the other two known VHE FSRQs (3C 279 and PKS 1222+216) have shown daily scale to sub-hour variability. The γ-ray SED combining AGILE, Fermi and MAGIC data joins smoothly and shows no hint of a break. The multi-frequency light curves suggest a common origin for the millimetre radio and HE γ-ray emission, and the HE γ-ray flaring starts when the new component is ejected from the 43 GHz VLBA core and the studied SED models fit the data well. However, the fast HE γ-ray variability requires that within the modelled large emitting region, more compact regions must exist. We suggest that these observed signatures would be most naturally explained by a turbulent plasma flowing at a relativistic speed down the jet and crossing a standing conical shock.

KW - Galaxies: active

KW - Galaxies: jets

KW - Gamma rays: galaxies

KW - Quasars: individual: PKS 1510-089

U2 - 10.1051/0004-6361/201423484

DO - 10.1051/0004-6361/201423484

M3 - Article

VL - 569

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - A46

ER -