RCS2.6-020437：一个在$z=0.6986$的高效宇宙望远镜
RCS2 J232727.6-020437: An Efficient Cosmic Telescope at $z=0.6986$
摘要：
我们提出了一个详细的星系团RCS 2 J232727.6-020437的引力透镜模型。由于星系团成员和ICL的宇宙学变暗，它的高红移（$z=0.6986$）使其成为研究背景星系的理想选择。使用新的ACS和WFC 3/IR HST数据，我们确定了16个多个图像。从MOSFIRE的后续研究中，我们在一张多重图像的光谱中发现了一条强发射线，这可能证实了该系统向$z=2.083$的红移。在$z=7$上，由于高度放大（$μ\gtrsim2$）的源平面面积为$\sim0.7$ arcmin $^2$，RCS 2 J232727.6-020437具有与哈勃前沿场星系团相当的透镜效应效率。我们发现了四个高度放大的$z\sim7$候选莱曼破裂星系，其中一个可能是多重成像。校正放大倍数后，我们发现所有四个星系都比$0.5 L_{\star}$暗。在Spitzer/IRAC [3.6]和[4.5]通道中的${>10σ}$检测到一个候选。用MOSFIRE进行的光谱跟踪没有从四个候选者中的任何一个中检测到莱曼α发射线。根据MOSFIRE光谱，我们对$5-14 \times 10^{-19}\, \mathrm{erg \,\, s^{-1} cm^{-2}}$（$5σ$）的莱曼-α通量设置中值上限。
英文摘要：
We present a detailed gravitational lens model of the galaxy cluster RCS2 J232727.6-020437. Due to cosmological dimming of cluster members and ICL, its high redshift ($z=0.6986$) makes it ideal for studying background galaxies. Using new ACS and WFC3/IR HST data, we identify 16 multiple images. From MOSFIRE follow up, we identify a strong emission line in the spectrum of one multiple image, likely confirming the redshift of that system to $z=2.083$. With a highly magnified ($μ\gtrsim2$) source plane area of $\sim0.7$ arcmin$^2$ at $z=7$, RCS2 J232727.6-020437 has a lensing efficiency comparable to the Hubble Frontier Fields clusters. We discover four highly magnified $z\sim7$ candidate Lyman-break galaxies behind the cluster, one of which may be multiply-imaged. Correcting for magnification, we find that all four galaxies are fainter than $0.5 L_{\star}$. One candidate is detected at ${>10σ}$ in both Spitzer/IRAC [3.6] and [4.5] channels. A spectroscopic follow-up with MOSFIRE does not result in the detection of the Lyman-alpha emission line from any of the four candidates. From the MOSFIRE spectra we place median upper limits on the Lyman-alpha flux of $5-14 \times 10^{-19}\, \mathrm{erg \,\, s^{-1} cm^{-2}}$ ($5σ$).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
