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arXiv 0903.3988astro-ph.CO
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Abell 1703和CL0024 +161星系团后红移z~ 6-7的亮强透镜星系

Bright Strongly Lensed Galaxies at Redshift z~ 6-7 behind the Clusters Abell 1703 and CL0024+161

W. Zheng, L. D. Bradley, R. J. Bouwens, H. C. Ford, G. D. Illingworth, N. Benitez, T. Broadhurst, B. Frye, L. Infante, M. J. Jee, V. Motta, X. W. Shu, A. Zitrin

摘要:

我们报告了在Abell 1703和CL 0024 +16后面发现的三个明亮的强透镜天体,这些天体来自对25平方角分深NICMOS数据的丢失搜索,具有深ACS光学覆盖。它们在低于8500 A的深ACS图像中未被检测到,并且在J和H波段中具有清晰的检测。与ACS、NICMOS和IRAC数据的拟合得到了z~6-7范围内的强测光红移,并在很大程度上排除了它们是低红移闯入者的可能性。所有三个物体都被延伸,并分解成一对明亮的结。Abell 1703中明亮的i波段脱落星系的H波段AB星等为23.9,这使它成为z>5.5的已知最亮星系候选者之一。我们的模型拟合表明,一个年轻的大质量星系只有6000万年的年龄,质量约为1 E10太阳质量。CL 0024 +16后面的候选脱落星系距离为2.5”(源平面约2 kpc),H波段AB星等分别为25.0和25.6。CL 0024 +16的透镜模型表明,这两个天体的本征星等相当,AB约为27.3,在z约为6.5时比L* 暗一等。它们相似的红移、光谱能量分布和光度,再加上它们在天空中非常接近,表明它们在空间上是相关的,并且在物理上可能是绑定的。结合这个样本与两个先前报道的,类似的放大星系候选人在z~6-8,我们发现,复杂系统的双核可能是一个共同的特点高红移星系。

英文摘要:

We report on the discovery of three bright, strongly-lensed objects behind Abell 1703 and CL0024+16 from a dropout search over 25 square arcminutes of deep NICMOS data, with deep ACS optical coverage. They are undetected in the deep ACS images below 8500 A and have clear detections in the J and H bands. Fits to the ACS, NICMOS and IRAC data yield robust photometric redshifts in the range z~6-7 and largely rule out the possibility that they are low-redshift interlopers. All three objects are extended, and resolved into a pair of bright knots. The bright i-band dropout in Abell 1703 has an H-band AB magnitude of 23.9, which makes it one of the brightest known galaxy candidates at z>5.5. Our model fits suggest a young, massive galaxy only ~ 60 million years old with a mass of ~ 1E10 solar mass. The dropout galaxy candidates behind CL0024+16 are separated by 2.5" (~ 2 kpc in the source plane), and have H-band AB magnitudes of 25.0 and 25.6. Lensing models of CL0024+16 suggest that the objects have comparable intrinsic magnitudes of AB ~ 27.3, approximately one magnitude fainter than L* at z~6.5. Their similar redshifts, spectral energy distribution, and luminosities, coupled with their very close proximity on the sky, suggest that they are spatially associated, and plausibly are physically bound. Combining this sample with two previously reported, similarly magnified galaxy candidates at z~6-8, we find that complex systems with dual nuclei may be a common feature of high-redshift galaxies.

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。

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