利用Fermi-LAT和MEGARA限制LINER外流的γ射线效率
Constraining the gamma-ray efficiency of LINER outflows with Fermi-LAT and MEGARA
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中文总结 AI 辅助
本研究结合MEGARA与Fermi-LAT数据，首次经验限制了LINER外流的γ射线辐射效率，发现其为低效高能粒子加速器，支持致密核喷流是LINER极端γ射线辐射的主要来源。
中文摘要 AI 辅助
低电离核发射线区（LINERs）通常存在电离气体外流，但它们作为高能粒子加速器的作用仍存在争议，尤其是在检测到NGC 4278的甚高能γ射线之后，这暗示其存在极端辐射效率。为了验证LINER的高能辐射是否由延伸的电离外流提供动力，还是需要致密的核喷流，我们对本地样本LINER的γ射线辐射效率进行了经验测定。我们结合了加那利大型望远镜上的高分辨率天文多光谱仪（MEGARA）的空间分辨光学积分场运动学，得到电离外流的动能功率，以及17年的Fermi大视场望远镜（Fermi-LAT）观测数据，推导了0.05–500 GeV的光度或95%置信上限。我们将该样本与典型星暴星系和射电星系一同置于光学/γ射线图中，首次给出了作为一个整体的LINER外流的γ射线辐射效率的经验上限。没有任何一个LINER被正式检测到（检测显著性TS≥16）。最强的限制来自射电噪LINER NGC 1052，其效率η<41%。对于其余源，Fermi-LAT的限制通常远高于外流动能功率（η≫100%），而三个源显示出微弱的发射迹象（9<TS<16）。我们得出结论，LINER中的延伸电离外流是低效的高能粒子加速器，与星暴超风类似。这些限制不支持外流是极端γ射线效率的唯一来源，而支持致密核喷流是产生最有效γ射线辐射的LINER的主要来源。
英文摘要
Low-Ionization Nuclear Emission-line Regions (LINERs) commonly host ionized gas outflows, but their role as high-energy particle accelerators remains debated, particularly following the very-high-energy $γ$-ray detection of NGC 4278, which implied extreme radiative efficiencies. We empirically determine the $γ$-ray radiative efficiency of a local sample of LINERs to test whether their high-energy emission can be powered by extended ionized outflows or requires compact nuclear jets. We combine spatially resolved optical integral-field kinematics from the Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía at the Gran Telescopio de Canarias, yielding ionized-outflow kinetic powers, with 17 years of Fermi-Large Area Telescope observations to derive 0.05--500 GeV luminosities or 95% confidence upper limits. We place the sample in an optical/$γ$-ray diagram alongside archetypal starbursts and radio galaxies. We present the first empirical upper limits on the $γ$-ray radiative efficiency of LINER outflows as a population. No LINER is formally detected ($TS \geq 16$). The strongest constraint is obtained for the radio-loud LINER NGC 1052, with $η< 41%$. For the remaining sources, the Fermi-LAT limits generally lie well above the outflow kinetic powers ($η\gg 100%$), while three sources show marginal hints of emission ($9 < TS < 16$). We conclude that extended ionized outflows in LINERs are highly inefficient high-energy particle accelerators, analogous to starburst superwinds. These constraints disfavor the outflows as the sole origin of extreme $γ$-ray efficiencies and favor compact nuclear jets for the most efficient $γ$-ray-emitting LINERs.
