WFI J2026−4536 and WFI J2033−4723: Two New Quadruple Gravitational Lenses
WFI J2026−4536 and WFI J2033−4723: Two New Quadruple Gravitational Lenses
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WFI J2026−4536 和 WFI J2033−4723：两个新型四重引力透镜
DOI：
10.1086/383295
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
H. Rix
中科院分区：
文献类型：
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作者：
N. Morgan;J. Caldwell;P. Schechter;A. Dressler;E. Egami;H. Rix
我们报告了两个新的引力透镜类星体WFI J2026-4536和WFI J2033-4723的发现，它们的源红移分别为z = 2.23和z = 1.66。这两个系统都是四重成像的，并且具有类似于PG 1115的图像配置。WFI J2026-4536的最大像距为1.“4，总亮度为g = 16.5，透镜环境相对简单，而WFI J2033-4723的最大像距为2.”5，估计总亮度为g = 17.9，20“内至少有6个星系的环境更复杂。在点扩散函数相减后，这两个系统的主透镜星系被检测到。在这些系统中的几个宽带流量比显示出强烈的（0.1-0.4等）与波长的趋势，这表明通过透镜星系的微透镜或差异消光。对于WFI J2026-4536，在3个月内，蓝色的总类星体通量变暗了0.1等，但红色的只有一半，这表明微透镜引起的变化。对于WFI J2033-4723，一些类星体成分的分辨光谱显示，发射线通量比与宏观模型预测的一致性比宽带或连续比更好，这也表明了微透镜效应。WFI J2026-4536的预测差异时间延迟较短，长延迟范围为1 - 2周，但WFI J2033-4723的预测差异时间延迟较长，范围为1 - 2个月。这两个系统都为未来的微透镜或时间延迟研究的监测活动提供了希望。
We report the discovery of two new gravitationally lensed quasars, WFI J2026-4536 and WFI J2033-4723, at respective source redshifts of z = 2.23 and z = 1.66. Both systems are quadruply imaged and have similar PG 1115–like image configurations. WFI J2026-4536 has a maximum image separation of 1.″4, a total brightness of g = 16.5, and a relatively simple lensing environment, while WFI J2033-4723 has a maximum image separation of 2.″5, an estimated total brightness of g ≈ 17.9, and a more complicated environment of at least six galaxies within 20″. The primary lensing galaxies are detected for both systems after point-spread function subtraction. Several of the broadband flux ratios in these systems show a strong (0.1–0.4 mag) trend with wavelength, suggesting either microlensing or differential extinction through the lensing galaxy. For WFI J2026-4536, the total quasar flux has dimmed by 0.1 mag in the blue but only half as much in the red over 3 months, suggestive of microlensing-induced variations. For WFI J2033-4723, resolved spectra of some of the quasar components reveal emission-line flux ratios that agree better with the macromodel predictions than either the broadband or continuum ratios, also indicative of microlensing. The predicted differential time delays for WFI J2026-4536 are short, ranging from 1 to 2 weeks for the long delay, but are longer for WFI J2033-4723, ranging from 1 to 2 months. Both systems hold promise for future monitoring campaigns aimed at microlensing or time delay studies.