A redshift z=6.56 galaxy behind the cluster Abell 370
A redshift z=6.56 galaxy behind the cluster Abell 370
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DOI：
10.1086/340424
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发表时间：
2002-04-01
影响因子：
4.9
通讯作者：
Motohara, K
中科院分区：
文献类型：
--
作者：
Hu, EM;Cowie, LL;Motohara, K
我们报告发现一个红移z = 6.56的星系位于星系团阿贝尔370的后面。HCM 6A是在10米凯克II望远镜上的低分辨率成像光谱仪（LRIS）照相机中使用中心为9152埃的118埃带通滤波器进行窄带成像调查时发现的。候选Lyalpha发射器被确定的发射的等效宽度和较低的波长通量在超深宽带图像的情况下。HCM 6A是第一个被确认有红移的星系，z > 6 W-λ（观测）= 190埃，通量= 2.7 x 10（-17）ergs cm（-2）s（-1）。用LRIS获得的光谱证实了发射线和跨线的连续中断，并显示出在蓝色侧具有陡峭衰减的不对称线轮廓。深斯巴鲁近红外冷却红外光谱仪和照相机的OHS图像在J，H，并延长采样K连续更长的波长，给出了一个一致的估计连续通量密度在这些线的区域（2.6 +/- 0.7）x 10（-30）尔格cm（-2）s（-1）Hz（-1）。线的宽度和强度，不对称的配置文件，和非常深的光谱中断是唯一一致的解释线作为一个红移Lyalpha功能。从这个星系团的详细透镜模型中，我们估计这个星系的透镜放大率为4.5，它位于距离星系团中心略大于1弧分的位置，无透镜的通量为6.5 x 10（-18）ergs cm（-2）s（-1）。这样一个星系的存在表明再电离时代已经过去了。z = 6.6
We report the discovery of a redshift z = 6.56 galaxy lying behind the cluster Abell 370. The object HCM 6A was found in a narrowband imaging survey using a 118 Angstrom bandpass filter centered at 9152 Angstrom in the Low-Resolution Imaging Spectrograph (LRIS) camera on the 10 m Keck II telescope. Candidate Lyalpha emitters were identified by the equivalent width of the emission and the absence of lower wavelength flux in ultradeep broadband images. HCM 6A is the first galaxy to be confirmed at redshift and has z > 6 W-lambda(observed) = 190 Angstrom, flux = 2.7 x 10(-17) ergs cm(-2) s(-1). Spectra obtained with LRIS confirm the emission line and the continuum break across the line and show an asymmetric line profile with steep falloff on the blue side. Deep Subaru nearinfrared Cooled Infrared Spectrograph and Camera for OHS images in J, H, and that extend the sampled K continuum to longer wavelengths give a consistent estimate of the continuum flux density in these line-free regions of (2.6 +/- 0.7) x 10(-30) ergs cm(-2) s(-1) Hz(-1). The line width and strength, asymmetric profile, and very deep spectral break are only consistent with the interpretation of the line as a redshifted Lyalpha feature. From the detailed lensing model of this cluster, we estimate a lensing amplification of 4.5 for this galaxy, which is located slightly over an arcminute from the center of the cluster, for an unlensed flux of 6.5 x 10(-18) ergs cm(-2) s(-1). The presence of such a galaxy suggests that the reionizing epoch is beyond. z = 6.6