Multi-wavelength characterization of the blazar S5 0716+714 during an unprecedented outburst phase

Research output

Abstract

Context. The BL Lac object S5 0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding to the brightest ever reported state of the source in the R-band. Aims.The comprehensive dataset collected is investigated in order to shed light on the mechanism of the broadband emission. Methods. Multi-wavelength light curves have been studied together with the broadband spectral energy distributions (SEDs). The sample includes data from Effelsberg, OVRO, Metsähovi, VLBI, CARMA, IRAM, SMA, Swift-UVOT, KVA, Tuorla, Steward, RINGO3, KANATA, AZT-8+ST7, Perkins, LX-200, Swift-XRT, NuSTAR, Fermi-LAT and MAGIC. Results. The flaring state of Phase A was detected in all the energy bands, providing for the first time a multi-wavelength sample of simultaneous data from the radio band to the very-high-energy (VHE, E > 100 GeV). In the constructed SED, the Swift-XRT+NuSTAR data constrain the transition between the synchrotron and inverse Compton components very accurately, while the second peak is constrained from 0.1 GeV to 600 GeV by Fermi+MAGIC data. The broadband SED cannot be described with a one-zone synchrotron self-Compton model as it severely underestimates the optical flux in order to reproduce the X-ray to -ray data. Instead we use a two-zone model. The electric vector position angle (EVPA) shows an unprecedented fast rotation. An estimation of the redshift of the source by combined high-energy (HE, 0.1 GeV < E < 100 GeV) and VHE data provides a value of z = 0:31 ± 0:02stats ± 0:05sys, confirming the literature value. Conclusions. The data show the VHE emission originating in the entrance and exit of a superluminal knot in and out of a recollimation shock in the inner jet. A shock-shock interaction in the jet seems responsible for the observed flares and EVPA swing. This scenario is also consistent with the SED modeling.

Original languageEnglish
Article numberA45
JournalAstronomy and Astrophysics
Volume619
DOIs
Publication statusPublished - 1 Nov 2018

Fingerprint

spectral energy distribution
outburst
wavelength
shock
broadband
wavelengths
energy
synchrotrons
spectral mixture analysis
very long base interferometry
entrances
flares
light curve
energy bands
rays
very long baseline interferometry
x rays
radio
interactions
distribution

Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

@article{00e79985ab2f4bee9c6b42756a31e437,
title = "Multi-wavelength characterization of the blazar S5 0716+714 during an unprecedented outburst phase",
abstract = "Context. The BL Lac object S5 0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding to the brightest ever reported state of the source in the R-band. Aims.The comprehensive dataset collected is investigated in order to shed light on the mechanism of the broadband emission. Methods. Multi-wavelength light curves have been studied together with the broadband spectral energy distributions (SEDs). The sample includes data from Effelsberg, OVRO, Mets{\"a}hovi, VLBI, CARMA, IRAM, SMA, Swift-UVOT, KVA, Tuorla, Steward, RINGO3, KANATA, AZT-8+ST7, Perkins, LX-200, Swift-XRT, NuSTAR, Fermi-LAT and MAGIC. Results. The flaring state of Phase A was detected in all the energy bands, providing for the first time a multi-wavelength sample of simultaneous data from the radio band to the very-high-energy (VHE, E > 100 GeV). In the constructed SED, the Swift-XRT+NuSTAR data constrain the transition between the synchrotron and inverse Compton components very accurately, while the second peak is constrained from 0.1 GeV to 600 GeV by Fermi+MAGIC data. The broadband SED cannot be described with a one-zone synchrotron self-Compton model as it severely underestimates the optical flux in order to reproduce the X-ray to -ray data. Instead we use a two-zone model. The electric vector position angle (EVPA) shows an unprecedented fast rotation. An estimation of the redshift of the source by combined high-energy (HE, 0.1 GeV < E < 100 GeV) and VHE data provides a value of z = 0:31 ± 0:02stats ± 0:05sys, confirming the literature value. Conclusions. The data show the VHE emission originating in the entrance and exit of a superluminal knot in and out of a recollimation shock in the inner jet. A shock-shock interaction in the jet seems responsible for the observed flares and EVPA swing. This scenario is also consistent with the SED modeling.",
keywords = "BL Lacertae objects: individual: S5 0716+714, Galaxies: active, Galaxies: jets, Gamma rays: galaxies",
author = "{MAGIC Collaboration} and Ahnen, {M. L.} and S. Ansoldi and Antonelli, {L. A.} and C. Arcaro and D. Baack and A. Babić and B. Banerjee 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 {Ch Berse}, R. and A. Berti and W. Bhattacharyya and A. Biland and O. Blanch and G. Bonnoli and R. Carosi and A. Carosi and G. Ceribella and A. Chatterjee and Colak, {S. M.} and P. Colin and E. Colombo and Contreras, {J. L.} and J. Cortina and S. Covino and P. Cumani and {Da Vela}, P. and F. Dazzi and {De Angelis}, A. and {De Lotto}, B. and M. Delfino and J. Delgado and {Di Pierro}, F. and A. Dom{\'i}nguez and {Dominis Prester}, D. and D. Dorner and M. Doro and Grishina, {T. S.} and S. Jorstad and Kopatskaya, {E. N.} and Larionov, {V. M.} and Larionova, {L. V.} and Morozova, {D. A.} and Savchenko, {S. S.} and I. Troitsky and Vasilyev, {A. A.} and Троицкая, {Юлия Вячеславовна}",
year = "2018",
month = "11",
day = "1",
doi = "10.1051/0004-6361/201832677",
language = "English",
volume = "619",
journal = "ASTRONOMY & ASTROPHYSICS",
issn = "0004-6361",
publisher = "EDP Sciences",

}

TY - JOUR

T1 - Multi-wavelength characterization of the blazar S5 0716+714 during an unprecedented outburst phase

AU - MAGIC Collaboration

AU - Ahnen, M. L.

AU - Ansoldi, S.

AU - Antonelli, L. A.

AU - Arcaro, C.

AU - Baack, D.

AU - Babić, A.

AU - Banerjee, B.

AU - Bangale, P.

AU - Barres De Almeida, U.

AU - Barrio, J. A.

AU - Becerra González, J.

AU - Bednarek, W.

AU - Bernardini, E.

AU - Ch Berse, R.

AU - Berti, A.

AU - Bhattacharyya, W.

AU - Biland, A.

AU - Blanch, O.

AU - Bonnoli, G.

AU - Carosi, R.

AU - Carosi, A.

AU - Ceribella, G.

AU - Chatterjee, A.

AU - Colak, S. M.

AU - Colin, P.

AU - Colombo, E.

AU - Contreras, J. L.

AU - Cortina, J.

AU - Covino, S.

AU - Cumani, P.

AU - Da Vela, P.

AU - Dazzi, F.

AU - De Angelis, A.

AU - De Lotto, B.

AU - Delfino, M.

AU - Delgado, J.

AU - Di Pierro, F.

AU - Domínguez, A.

AU - Dominis Prester, D.

AU - Dorner, D.

AU - Doro, M.

AU - Grishina, T. S.

AU - Jorstad, S.

AU - Kopatskaya, E. N.

AU - Larionov, V. M.

AU - Larionova, L. V.

AU - Morozova, D. A.

AU - Savchenko, S. S.

AU - Troitsky, I.

AU - Vasilyev, A. A.

AU - Троицкая, Юлия Вячеславовна

PY - 2018/11/1

Y1 - 2018/11/1

N2 - Context. The BL Lac object S5 0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding to the brightest ever reported state of the source in the R-band. Aims.The comprehensive dataset collected is investigated in order to shed light on the mechanism of the broadband emission. Methods. Multi-wavelength light curves have been studied together with the broadband spectral energy distributions (SEDs). The sample includes data from Effelsberg, OVRO, Metsähovi, VLBI, CARMA, IRAM, SMA, Swift-UVOT, KVA, Tuorla, Steward, RINGO3, KANATA, AZT-8+ST7, Perkins, LX-200, Swift-XRT, NuSTAR, Fermi-LAT and MAGIC. Results. The flaring state of Phase A was detected in all the energy bands, providing for the first time a multi-wavelength sample of simultaneous data from the radio band to the very-high-energy (VHE, E > 100 GeV). In the constructed SED, the Swift-XRT+NuSTAR data constrain the transition between the synchrotron and inverse Compton components very accurately, while the second peak is constrained from 0.1 GeV to 600 GeV by Fermi+MAGIC data. The broadband SED cannot be described with a one-zone synchrotron self-Compton model as it severely underestimates the optical flux in order to reproduce the X-ray to -ray data. Instead we use a two-zone model. The electric vector position angle (EVPA) shows an unprecedented fast rotation. An estimation of the redshift of the source by combined high-energy (HE, 0.1 GeV < E < 100 GeV) and VHE data provides a value of z = 0:31 ± 0:02stats ± 0:05sys, confirming the literature value. Conclusions. The data show the VHE emission originating in the entrance and exit of a superluminal knot in and out of a recollimation shock in the inner jet. A shock-shock interaction in the jet seems responsible for the observed flares and EVPA swing. This scenario is also consistent with the SED modeling.

AB - Context. The BL Lac object S5 0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding to the brightest ever reported state of the source in the R-band. Aims.The comprehensive dataset collected is investigated in order to shed light on the mechanism of the broadband emission. Methods. Multi-wavelength light curves have been studied together with the broadband spectral energy distributions (SEDs). The sample includes data from Effelsberg, OVRO, Metsähovi, VLBI, CARMA, IRAM, SMA, Swift-UVOT, KVA, Tuorla, Steward, RINGO3, KANATA, AZT-8+ST7, Perkins, LX-200, Swift-XRT, NuSTAR, Fermi-LAT and MAGIC. Results. The flaring state of Phase A was detected in all the energy bands, providing for the first time a multi-wavelength sample of simultaneous data from the radio band to the very-high-energy (VHE, E > 100 GeV). In the constructed SED, the Swift-XRT+NuSTAR data constrain the transition between the synchrotron and inverse Compton components very accurately, while the second peak is constrained from 0.1 GeV to 600 GeV by Fermi+MAGIC data. The broadband SED cannot be described with a one-zone synchrotron self-Compton model as it severely underestimates the optical flux in order to reproduce the X-ray to -ray data. Instead we use a two-zone model. The electric vector position angle (EVPA) shows an unprecedented fast rotation. An estimation of the redshift of the source by combined high-energy (HE, 0.1 GeV < E < 100 GeV) and VHE data provides a value of z = 0:31 ± 0:02stats ± 0:05sys, confirming the literature value. Conclusions. The data show the VHE emission originating in the entrance and exit of a superluminal knot in and out of a recollimation shock in the inner jet. A shock-shock interaction in the jet seems responsible for the observed flares and EVPA swing. This scenario is also consistent with the SED modeling.

KW - BL Lacertae objects: individual: S5 0716+714

KW - Galaxies: active

KW - Galaxies: jets

KW - Gamma rays: galaxies

UR - http://www.scopus.com/inward/record.url?scp=85056511739&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/201832677

DO - 10.1051/0004-6361/201832677

M3 - Article

AN - SCOPUS:85056511739

VL - 619

JO - ASTRONOMY & ASTROPHYSICS

JF - ASTRONOMY & ASTROPHYSICS

SN - 0004-6361

M1 - A45

ER -