Deep Imaging of the Field of the High-Redshift Radio Source 4C 23.56
Deep Imaging of the Field of the High-Redshift Radio Source 4C 23.56
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高红移射电源 4C 23.56 场的深度成像
DOI：
10.1086/312981
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
K. Chambers
中科院分区：
文献类型：
--
作者：
G. P. Knopp;K. Chambers
我们给出了以巨星(~0.5Mpc)高红移(z=2.479)超陡谱射电源4C23.56为中心的1.25arcmin2场的深红外和光学成像。宿主星系的光学/红外连续体形态是不对称的，具有强烈的颜色梯度和巨大的双锥发射线星云。4C23.56的形态最好的描述是一个尘埃星系，它由一个活动星系核发出的光束照射，散射到我们的视线中。我们确定了场中K‘波段数目的极限为K’=22.5MAG，并发现与其他K‘波段调查相比，K’=19-21MAG的天体数量略有增加。利用孔径测光技术在U‘、Nb、V、I和K’五个波段上测量了场中117个物体的光谱能量分布。从SED中，我们区分出三个可能的天体子集作为z~2.48伴星的候选者：发射线星系、非常红星系和平光谱恒星形成星系。该场有九个候选天体，其线发射在以红移的Lyα线为中心的窄带内，相比之下，预期最多有三个前景[O II]发射体可以模拟Lyα源。我们在野外发现了高密度的暗红色物体，其中有两个物体的K-K‘和GT；6Mag。
We present deep infrared and optical imaging of a 1.25 arcmin2 field centered on the giant (~0.5 Mpc) high-redshift (z = 2.479) ultra-steep-spectrum radio source 4C 23.56. The optical/infrared continuum morphology of the host galaxy is asymmetric, with strong color gradients and an enormous biconical emission-line nebula. The morphology of 4C 23.56 is best described by a dusty galaxy illuminated by a beam from an active galactic nucleus that is scattered into our line of sight. We determine the K' band number counts in the field to a limit of K' = 22.5 mag and find a marginally significant excess of objects with K' = 19-21 mag, compared to other K' band surveys. Spectral energy distributions (SEDs) of 117 objects in the field are constructed from aperture photometry in five bands (U', NB, V, I, and K'). From the SEDs we distinguish three subsets of objects as possible candidates for z ~ 2.48 companions: emission-line galaxies, very red galaxies, and flat-spectrum star-forming galaxies. The field has nine candidate objects with line emission in a narrow band centered on the redshifted Lyα line, compared to an expected number of at most three foreground [O II] emitters that could mimic Lyα sources. We find a high density of faint, very red objects with I-K' > 4 mag in the field, including two with I-K' > 6 mag.