TY - JOUR
T1 - A near magnetic-to-kinetic energy equipartition flare from the relativistic jet in AO 0235 + 164 during 2013–2019
AU - Cheong, Whee Yeon
AU - Lee, Sang Sung
AU - Kim, Sang Hyun
AU - Kang, Sincheol
AU - Kim, Jae Young
AU - Rani, Bindu
AU - Readhead, Anthony C.S.
AU - Kiehlmann, Sebastian
AU - Lähteenmäki, Anne
AU - Tornikoski, Merja
AU - Tammi, Joni
AU - Ramakrishnan, Venkatessh
AU - Agudo, Iván
AU - Fuentes, Antonio
AU - Traianou, Efthalia
AU - Escudero, Juan
AU - Thum, Clemens
AU - Myserlis, Ioannis
AU - Casadio, Carolina
AU - Gurwell, Mark
N1 - Funding Information:
This research made use of astropy , a community-developed core Python package for Astronomy (Astropy Collaboration , ). WYC, SSL, SHK and SK were supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MIST) (2020R1A2C2009003).
Funding Information:
We thank the anonymous reviewer for valuable comments and suggestions that helped to improve the paper. The manuscript was improved by the helpful comments of Filippo D’Ammando, Tonia Venters, Dave Thompson, and Deirdre Horan. This research has made use of data from the OVRO 40-m monitoring programme (Richards et al. ), supported by private funding from the California Insitute of Technology and the Max Planck Institute for Radio Astronomy, and by NASA grants NNX08AW31G, NNX11A043G,and NNX14AQ89G and NSF grants AST-0808050andAST-1109911. This publication makes use of data obtained at Metsähovi Radio Observatory, operated by Aalto University in Finland. JYK was supported for this research by the National Research Foundation of Korea (NRF) funded by the Korean government (Ministry of Science and ICT; grant no. 2022R1C1C1005255). IA acknowledges financial support from the Spanish ‘Ministerio de Ciencia e Innovación’ (MCINN) through the ‘Center of Excellence Severo Ochoa’ award for the Instituto de Astrofísica de Andalucía-CSIC (SEV-2017-0709). Acquisition and reduction of the MAPCAT data was supported in part by MICINN through grants AYA2016-80889-P and PID2019-107847RB-C44. The POLAMI observations were carried out at the IRAM 30m Telescope. IRAM was supported by INSU,CNRS (France), MPG (Germany), and IGN (Spain). CC acknowledges support from the European Research Council (ERC) under the HORIZON ERC Grants 2021 programme under grant agreement no. 101040021. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00001.CAL. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. We recognize that Maunakea is a culturally important site for the indigenous Hawaiian people; we are privileged to study the cosmos from its summit. This study makes use of VLBA data from the VLBA-BU Blazar Monitoring Program (BEAM-ME and VLBA-BU-BLAZAR; http://www.bu.edu/blazars/BEAM-ME.html ), funded by NASA through the Fermi Guest Investigator Program. The VLBA is an instrument of the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated by Associated Universities, Inc.
Funding Information:
The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucléaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden.
Funding Information:
Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’Études Spatiales in France. This work performed in part under DOE Contract DE-AC02-76SF00515.
Funding Information:
We thank the anonymous reviewer for valuable comments and suggestions that helped to improve the paper. The manuscript was improved by the helpful comments of Filippo D’Ammando, Tonia Venters, Dave Thompson, and Deirdre Horan. This research has made use of data from the OVRO 40-m monitoring programme (Richards et al. 2011), supported by private funding from the California Insitute of Technology and the Max Planck Institute for Radio Astronomy, and by NASA grants NNX08AW31G, NNX11A043G, and NNX14AQ89G and NSF grants AST-0808050 and AST- 1109911. This publication makes use of data obtained at Metsähovi Radio Observatory, operated by Aalto University in Finland. JYK was supported for this research by the National Research Foundation of Korea (NRF) funded by the Korean government (Ministry of Science and ICT; grant no. 2022R1C1C1005255). IA acknowledges financial support from the Spanish ‘Ministerio de Ciencia e Innovación’ (MCINN) through the ‘Center of Excellence Severo Ochoa’ award for the Instituto de Astrofísica de Andalucía-CSIC (SEV-2017-0709). Acquisition and reduction of the MAPCAT data was supported in part by MICINN through grants AYA2016-80889-P and PID2019-107847RB-C44. The POLAMI observations were carried out at the IRAM 30m Telescope. IRAM was supported by INSU,CNRS (France), MPG (Germany), and IGN (Spain). CC acknowledges support from the European Research Council (〈0:funding-sou rce 3:href="http://dx.doi.org/10.13039/100010663"〉ERC〈/0:fundin g-source〉) under the HORIZON ERC Grants 2021 programme under grant agreement no. 101040021. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00001.CAL. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. We recognize that Maunakea is a culturally important site for the indigenous Hawaiian people; we are privileged to study the cosmos from its summit. This study makes use of VLBA data from the VLBA-BU Blazar Monitoring Program (BEAM-ME and VLBA-BU-BLAZAR; http://www.bu.edu/blazars/BEAM-ME.html), funded by NASA through the Fermi Guest Investigator Program. The VLBA is an instrument of the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated by Associated Universities, Inc. The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucléaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’Études Spatiales in France. This work performed in part under DOE Contract DE-AC02-76SF00515. This research made use of ASTROPY,9 a community-developed core Python package for Astronomy (Astropy Collaboration 2013, 2018). WYC, SSL, SHK and SK were supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MIST) (2020R1A2C2009003).
Publisher Copyright:
© 2023 The Author(s).
PY - 2024/1/1
Y1 - 2024/1/1
N2 - We present the multiwavelength flaring activity of the blazar AO 0235 + 164 during its recent active period from 2013 to 2019. From a discrete correlation function analysis, we find a significant (> 95 per cent) correlation between radio and gamma-ray light curves with flares at longer wavelengths following flares at shorter wavelengths. We identify a new jet component in 43 GHz Very Long Baseline Array data that was ejected from the radio core on MJD 57246+−3026 (2015 August 12), during the peak of the 2015 radio flare. From the analysis of the jet component, we derived a Doppler factor of δvar = 28.5 ± 8.4, a bulk Lorentz factor of Γ = 16.8+−33.16, and an intrinsic viewing angle of θv = 1.42+−01.5207 degrees. Investigation of the quasi-simultaneous radio data revealed a partially absorbed spectrum with the turnover frequency varying in the range of 10−70 GHz and the peak flux density varying in the range of 0.7−4 Jy. We find the synchrotron self-absorption magnetic field strength to be BSSA = 15.3+−1412.06 mG at the peak of the 2015 radio flare, which is comparable to the equipartition magnetic field strength of BEQ = 43.6+−1010.46 mG calculated for the same epoch. Additional analysis of the radio emission region in the relativistic jet of AO 0235 + 164 suggests that it did not significantly deviate from equipartition during its recent flaring activity.
AB - We present the multiwavelength flaring activity of the blazar AO 0235 + 164 during its recent active period from 2013 to 2019. From a discrete correlation function analysis, we find a significant (> 95 per cent) correlation between radio and gamma-ray light curves with flares at longer wavelengths following flares at shorter wavelengths. We identify a new jet component in 43 GHz Very Long Baseline Array data that was ejected from the radio core on MJD 57246+−3026 (2015 August 12), during the peak of the 2015 radio flare. From the analysis of the jet component, we derived a Doppler factor of δvar = 28.5 ± 8.4, a bulk Lorentz factor of Γ = 16.8+−33.16, and an intrinsic viewing angle of θv = 1.42+−01.5207 degrees. Investigation of the quasi-simultaneous radio data revealed a partially absorbed spectrum with the turnover frequency varying in the range of 10−70 GHz and the peak flux density varying in the range of 0.7−4 Jy. We find the synchrotron self-absorption magnetic field strength to be BSSA = 15.3+−1412.06 mG at the peak of the 2015 radio flare, which is comparable to the equipartition magnetic field strength of BEQ = 43.6+−1010.46 mG calculated for the same epoch. Additional analysis of the radio emission region in the relativistic jet of AO 0235 + 164 suggests that it did not significantly deviate from equipartition during its recent flaring activity.
KW - BL Lacertae objects: individual: AO 0235 + 164
KW - galaxies: active
KW - galaxies: jets
KW - gamma-rays: galaxies
KW - radio continuum: galaxies
UR - http://www.scopus.com/inward/record.url?scp=85177495775&partnerID=8YFLogxK
U2 - 10.1093/mnras/stad3250
DO - 10.1093/mnras/stad3250
M3 - Article
AN - SCOPUS:85177495775
SN - 0035-8711
VL - 527
SP - 882
EP - 894
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -