论文标题
五个Z〜0.3-0.4的属性已确认已确认的LYC泄漏器：VLT/XSHOOTER观测值
Properties of five z~0.3-0.4 confirmed LyC leakers: VLT/XShooter observations
论文作者
论文摘要
使用新的VLT/Xshooter光谱观测值，我们分析了五个Z〜0.3-0.4确认的LYC泄漏器的物理特性。强共振MGII 2796,2803发射线（I（2796,2803）/I（HBETA）= 10-38％）和非谐振FEII* 2612,2626发射线分别在五个和三个星系的光谱中观察到。我们发现高电子密度NE〜400cm-3，显着高于典型的低Z，但与在Z〜2-3恒星形成星系中测得的电子密度相当。星系的平均值为logN/o = -1.16，接近在12+徽标/h = 7.7-8.1的金属度范围内恒星形成（SF）星系的最大值。 Izotov等人发现的所有11个低Z Lyc发射星系。 （2016，2018），包括本研究中考虑的特征，其特征是高EW（HBETA）〜200-400A，高电离参数（log（u）= -2.5至-1.7），高平均平均光子化光子生产效率ξ= 10^{25.54} HZ ERG-1和硬离子的辐射。在BPT图上，我们发现从低$ z $ mainsemence SFGS的泄漏器与LBG的局部类似物和Z〜2-3的极端SF星系相同的泄漏器。我们证实了Izotov等人提出的HEI发射线诊断的有效性。 （2017年）在寻找LYC泄漏候选物并发现其强度比对应于中性氢柱密度低的中位数n（hi）= 10^{17} -5x10^{17} cm-2，允许允许LYC辐射的泄漏，这可能是由于其密度构成的HII区域所致。
Using new VLT/XShooter spectral observations we analyse the physical properties of five z~0.3-0.4 confirmed LyC leakers. Strong resonant MgII 2796,2803 emission lines (I(2796,2803)/I(Hbeta)=10-38 per cent) and non-resonant FeII* 2612,2626 emission lines are observed in spectra of five and three galaxies, respectively. We find high electron densities Ne~400cm-3, significantly higher than in typical low-z, but comparable to those measured in z~2-3 star-forming galaxies. The galaxies have a mean value of logN/O=-1.16, close to the maximum values found for star-forming (SF) galaxies in the metallicity range of 12+logO/H=7.7-8.1. All 11 low-z LyC emitting galaxies found by Izotov et al. (2016, 2018), including the ones considered in the present study, are characterised by high EW(Hbeta)~200-400A, high ionisation parameter (log(U)=-2.5 to -1.7), high average ionising photon production efficiency ξ= 10^{25.54} Hz erg-1 and hard ionising radiation. On the BPT diagram we find the same offset of our leakers from low-$z$ main-sequence SFGs as that for local analogues of LBGs and extreme SF galaxies at z~2-3. We confirm the effectiveness of the HeI emission lines diagnostics proposed by Izotov et al. (2017) in searching for LyC leaker candidates and find that their intensity ratios correspond to those in a median with low neutral hydrogen column density N(HI)=10^{17}-5x10^{17} cm-2 that permit leakage of LyC radiation, likely due to their density-bounded HII regions.
