论文标题
关于FR II射线星系喷射的相对热对的重要性
On the significance of relativistically hot pairs in the jets of FR II radio galaxies
论文作者
论文摘要
FR II星系中无线电裂片的能量组成$ - $ - $ $ $ $ $ $通过将其无线电发光性与外部介质$ - $中充气腔所需的力量进行比较，似乎排除了质子通过质子的能量统治的可能性。此外，如果喷气机以冷质子的动能为主，则很难在喷气机的末端冲击中有效加速瘦素。假设在电击中保留了叶子，质子和磁场的相对能量含量，则以上意味着大规模喷气机也应在脑电图上能够在能量上统治：$ p _ {\ rm e，j} \ gtrsim p _ {\ rm p，j} $。另一方面，先前对大规模和无线电芯中的小规模喷气式的研究表明，$ n _ {\ rm e}/n _ {\ rm p} \ sim 20 $的订单的一对含量（每个质子的电子和正上音）的订单（\ rm E}/n _ {\ rm E}/n _ {\ rm e}/n _ {\ rm e}/n _ {\ rm e}/n _ sim 20 $。进一步假设喷气机的颗粒组成不会超出大尺度，我们表明这意味着在$ \barγ_{\ rm e，j} \ gtrsim 70（1+χ_ {\ rm p} _ {\ rm p}）的大规模喷射中的平均随机lorentz因子。 e}）$，并且质子应与$χ_ {\ rm p} \ equiv（ε_ {\ rm p} + p _ {\ rm p} {\ rm p}）/ρ_{\ rm p} $ε_ {\ rm p} $质子的内部能量密度，$ρ_ {\ rm p} c^2 $质子的休息质量能量密度。我们得出了通过电子旋律对和质子电子等离子体加载内部喷气机的必要条件，并提供了论证，即喷气机中的瘦素加热以磁重新连接为主。
The energetic composition of radio lobes in the FR II galaxies $-$ estimated by comparing their radio luminosities with the powers required to inflate cavities in the external medium $-$ seems to exclude the possibility of their energetic domination by protons. Furthermore, if the jets were dominated by the kinetic energy of cold protons, it would be difficult to efficiently accelerate leptons in the jets' terminal shocks. Assuming that the relative energy contents of leptons, protons and magnetic fields are preserved across the shocks, the above implies that the large-scale jets should also be energetically dominated by leptons: $P_{\rm e,j} \gtrsim P_{\rm p,j}$. On the other hand, previous studies of small-scale jets in blazars and radio cores suggest a pair content (number of electrons and positrons per proton) of the order of $n_{\rm e}/n_{\rm p} \sim 20$. Assuming further that the particle composition of jets does not evolve beyond the blazar scales, we show that this implies an average random Lorentz factor of leptons in large-scale jets of $\barγ_{\rm e,j} \gtrsim 70(1+χ_{\rm p})(20n_{\rm p}/n_{\rm e})$, and that the protons should be mildly relativistic with $χ_{\rm p} \equiv (ε_{\rm p} + p_{\rm p})/ρ_{\rm p} c^2 \lesssim 2$, $p_{\rm p}$ the pressure of protons, $ε_{\rm p}$ the internal energy density of protons, and $ρ_{\rm p} c^2$ the rest-mass energy density of protons. We derive the necessary conditions for loading the inner jets by electron-positron pairs and proton-electron plasma, and provide arguments that heating of leptons in jets is dominated by magnetic reconnection.
