论文标题
高合成螺旋体BL LAC对象的宽带研究1ES 1218+304
Broadband Study of High-Synchrotron-Peaked BL Lac Object 1ES 1218+304
论文作者
论文摘要
使用{\ it swift uvot/xrt}，{\ it nustar}和{\ it {\ it fermi-lat}的数据研究了从高合格峰bl lac 1ES 1218+304的多波长发射的来源。对2008 - 2020年期间在$γ$ -Ray（$> 100 $ MEV），X射线（0.3-70 KEV）和光学/UV频段中观察到的数据进行了详细的时间和光谱分析。 $γ$ -Ray频谱很难，光子指数为$ 1.71 \ pm0.02 $高于$ 100 $ MEV。 {\ it swift uvot/xrt}数据显示了UV/光学带和X射线频段的通量增加；最高$ 0.3-3 $ kev X射线通量为$（1.13 \ pm0.02）\ times10^{ - 10} {\ rm erg \：cm^{ - 2} \：s^{ - 1}}} $。在0.3-10 KEV范围内，平均的X射线光子指数为$> 2.0 $，在3-50 KEV频段中柔软至$ 2.56 \ pm 0.028 $。但是，在某些时期，X射线光子指数变得极为硬（$ <1.8 $），这表明同步加速器组件的峰值高于$ 1 $ kev，因此1ES 1218+304的行为就像是极端的同步子BL lac。 1ES 1218+304的最难的X射线光子指数为$ 1.60 \ pm 0.05 $在MJD 58489上。时间平均的多波长光谱能量分布是在单区域同步的自comptron self-compton leptonic leptonic模型中建模的，该模型使用破碎的电力lawseles和无量身能量分配，并具有付出的电子能量分配。当电子能量分布为$ e _ {\ rm e}^{ - 2.1} $时，数据可以很好地解释，最高可扩展到$γ_ {\ rm br/cut} \ simeq（1.7-4.3）\ times10^{5} $，磁场很弱（$ b \ sim1.5 \ g）。通过求解发射区域电子演化的动力学方程，考虑了颗粒注入，冷却和逃逸，讨论了所获得的电子能量分布。
The origin of the multiwavelength emission from the high-synchrotron-peaked BL Lac 1ES 1218+304 is studied using the data from {\it Swift UVOT/XRT}, {\it NuSTAR} and {\it Fermi-LAT}. A detailed temporal and spectral analysis of the data observed during 2008-2020 in the $γ$-ray ($>100$ MeV), X-ray (0.3-70 keV), and optical/UV bands is performed. The $γ$-ray spectrum is hard with a photon index of $1.71\pm0.02$ above $100$ MeV. The {\it Swift UVOT/XRT} data show a flux increase in the UV/optical and X-ray bands; the highest $0.3-3$ keV X-ray flux was $(1.13\pm0.02)\times10^{-10}{\rm erg\:cm^{-2}\:s^{-1}}$. In the 0.3-10 keV range the averaged X-ray photon index is $>2.0$ which softens to $2.56 \pm 0.028$ in the 3-50 keV band. However, in some periods, the X-ray photon index became extremely hard ($<1.8$), indicating that the peak of the synchrotron component was above $1$ keV, and so 1ES 1218+304 behaved like an extreme synchrotron BL Lac. The hardest X-ray photon index of 1ES 1218+304 was $1.60 \pm 0.05 $ on MJD 58489. The time-averaged multiwavelength spectral energy distribution is modeled within a one-zone synchrotron self-Compton leptonic model using a broken power-law and power-law with an exponential cutoff electron energy distributions. The data are well explained when the electron energy distribution is $E_{\rm e}^{-2.1}$ extending up to $γ_{\rm br/cut}\simeq(1.7-4.3)\times10^{5}$, and the magnetic field is weak ($B\sim1.5\times10^{-2}$ G). By solving the kinetic equation for electron evolution in the emitting region, the obtained electron energy distributions are discussed considering particle injection, cooling, and escape.
