Title: Modeling of the time-resolved spectral energy distribution of blazar OJ 287 from 2008 to 2023: a comprehensive multi-epoch study Show Chinese title

Title: 2008年至2023年耀变体OJ 287的时间分辨光谱能量分布建模：一项全面的多历元研究

Abstract: We present a comprehensive analysis of the time-resolved spectral energy distributions (SEDs) of the blazar OJ 287 over a 15-year period (2008-2023), using multi-wavelength data. In the $\gamma$-ray band, multiple flaring episodes were observed, with the strongest flare reaching a peak flux of $(5.60\pm1.11)\times10^{-7}\:{\rm photons\:cm^{-2}\:s^{-1}}$ on MJD 55869.03 (04 November 2011). In the optical/UV band, the source was in an active state between MJD 57360 (04 December 2015) and 57960 (26 July 2017), during which the highest flux of $(1.07\pm0.02)\times10^{-10}\:{\rm erg\:cm^{-2}\:s^{-1}}$ was observed on MJD 57681.23 (20 October 2016). In the X-ray band, both the flux and spectral index exhibit variability. To investigate the origin of the broadband emission from OJ 287, we systematically modeled 739 quasi-simultaneous SEDs using a leptonic model that self-consistently accounts for particle injection and cooling. This analysis is possible thanks to the recent development of a surrogate neural-network-based model, trained on kinetic simulations. This innovative, time-resolved, neural network-based approach overcomes the limitations of traditional single-epoch SED modeling, enabling to explore the temporal evolution of key model parameters, such as the magnetic field strength, Doppler factor, and electron injection distribution, across different states of the source. We identified distinct emission states characterized by unique combinations of magnetic field $ B $, electron index $ p $, and Doppler boost $ \delta $, associated to different underlying mechanisms such as varying acceleration processes (e.g., shocks, turbulence) and magnetic confinement. The analysis provides insights into the jet physics processes, including particle acceleration mechanisms and dynamic changes in the jet structure. Show Chinese abstract

Abstract: 我们对耀变体OJ 287在15年期间（2008-2023）的时间分辨光谱能量分布（SEDs）进行了全面分析，使用了多波段数据。 在$\gamma$射线波段，观察到了多次爆发事件，最强的爆发在MJD 55869.03（2011年11月4日）达到峰值通量$(5.60\pm1.11)\times10^{-7}\:{\rm photons\:cm^{-2}\:s^{-1}}$。 在光学/紫外波段，源在MJD 57360（2015年12月4日）到57960（2017年7月26日）之间处于活跃状态，在此期间观测到最高通量$(1.07\pm0.02)\times10^{-10}\:{\rm erg\:cm^{-2}\:s^{-1}}$，出现在MJD 57681.23（2016年10月20日）。 在X射线波段，通量和光谱指数都表现出变化。 为了研究OJ 287宽波段辐射的起源，我们系统地使用一个自洽考虑粒子注入和冷却的轻子模型对739个准同时的SEDs进行了建模。 这一分析得益于最近开发的一种基于代理神经网络的模型，该模型是基于动力学模拟训练的。 这种创新的时间分辨神经网络方法克服了传统单epoch SED建模的局限性，能够探索关键模型参数随时间的变化，例如磁场强度、多普勒因子和电子注入分布，在源的不同状态下。 我们识别出由独特的磁场$ B $、电子指数$p $和多普勒增强$ \delta $组合表征的不同发射状态，这些状态与不同的基本机制相关，例如不同的加速过程（如激波、湍流）和磁场约束。 该分析提供了关于喷流物理过程的见解，包括粒子加速机制和喷流结构的动态变化。