1. A near magnetic-to-kinetic energy equipartition flare from the relativistic jet in AO 0235 + 164 during 2013–2019.
- Author
-
Cheong, Whee Yeon, Lee, Sang-Sung, Kim, Sang-Hyun, Kang, Sincheol, Kim, Jae Young, Rani, Bindu, Readhead, Anthony C S, Kiehlmann, Sebastian, Lähteenmäki, Anne, Tornikoski, Merja, Tammi, Joni, Ramakrishnan, Venkatessh, Agudo, Iván, Fuentes, Antonio, Traianou, Efthalia, Escudero, Juan, Thum, Clemens, Myserlis, Ioannis, Casadio, Carolina, and Gurwell, Mark
- Subjects
GAMMA ray bursts ,MAGNETIC flux density ,LIGHT curves ,BL Lacertae objects ,FREQUENCY spectra ,ACTINIC flux - Abstract
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 (|$\gt 95~{{\ \rm per\ cent}}$|) 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 |$57246^{+26}_{-30}$| (2015 August 12), during the peak of the 2015 radio flare. From the analysis of the jet component, we derived a Doppler factor of δ
var = 28.5 ± 8.4, a bulk Lorentz factor of |$\Gamma =16.8^{+3.6}_{-3.1}$| , and an intrinsic viewing angle of |$\theta _{\rm v}=1.42^{+1.07}_{-0.52}\textrm {~degrees}$|. 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 |$B_{\rm SSA}=15.3^{+12.6}_{-14.0}\textrm {~mG}$| at the peak of the 2015 radio flare, which is comparable to the equipartition magnetic field strength of |$B_{\rm EQ}=43.6^{+10.6}_{-10.4}\textrm {~mG}$| 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. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF