AI 中文总结
本研究通过多波段观测分析，证实疑似高红移引力透镜类星体J0109-5424实为中等红移FeLoBAL类星体，且不支持P170+20的引力透镜本质，凸显了高红移引力透镜类星体遴选的难度。
AI 中文摘要
我们对两个被引力透镜放大的红移z>6类星体候选体J0109-5424和P170+20开展了详细的多波段分析。利用Aether巡天的JWST/NIRSpec近红外数据，我们证实J0109-5424实际是红移z=2.07的FeLoBAL类星体，其强铁宽吸收线模拟出了莱曼断裂的特征。从Pβ发射线，我们估算该类星体的黑洞质量为3.9×10^8倍太阳质量，热光度Lbol=7.7×10^45 erg/s。对P170+20开展的后续HST/ACS WFC F555W滤镜成像（探测类星体莱曼限以下的发射）显示，存在一个距离类星体位置0.09±0.04角秒的致密源，点扩散函数（PSF）建模与扣除后未发现延展发射的证据，这与前景星系作为透镜的情况不符。此外，我们获取了Gemini-South/Flamingos 2近红外观测数据，以补充已有的Gemini-North/GMOS光学光谱，光谱分析表明P170+20的观测光谱形态与复合类星体和M型矮星的光谱一致，但该解释仍存在不确定性，因为0.1角秒内超冷矮星与类星体的偶然并合概率较低。总体而言，我们的研究确定J0109-5424是中等红移源，且不支持P170+20为引力透镜天体，尽管无法完全排除该可能性，凸显了选择高红移引力透镜类星体的挑战。
英文摘要
We present a detailed multi-wavelength analysis of two gravitationally lensed z>6 quasar candidates: J0109-5424 and P170+20. Using JWST/NIRSpec near-infrared data from the Aether survey, we demonstrate that J0109-5424 is in fact a FeLoBAL quasar at z=2.07, exhibiting strong iron broad absorption lines that mimic the Lyman break. From the Pabeta emission line, we estimate a black hole mass of 3.9 x 10^8 Msun and a bolometric luminosity of Lbol = 7.7 x 10^45 erg/s for this quasar. Follow-up HST/ACS WFC imaging of P170+20 with the F555W filter, probing emission below the Lyman limit of the quasar, reveals a compact source located 0.09+/-0.04 arcsec from the quasar position. PSF modelling and subtraction yield no evidence for extended emission. This is inconsistent with a foreground galaxy acting as a lens. Furthermore, we obtain Gemini-South/Flamingos 2 near-infrared observations to complement the existing optical Gemini-North/GMOS spectrum of P170+20. Our spectral analysis shows that the observed spectral shape of P170+20 is consistent with a composite quasar and M-dwarf spectrum. However, this interpretation remains uncertain, as a chance alignment between an ultracool dwarf and a quasar within 0.1 arcsec would be unlikely. Overall, our findings establish J0109-5424 as an intermediate redshift source and do not favor the lensed nature of P170+20, although this possibility cannot be conclusively ruled out, highlighting the challenges of selecting lensed quasars at high redshift.
CommentsAccepted for publication in the Astrophysical Journal, 10 pages, 4 figures
