The AGEL Survey: Spectroscopic Confirmation of Strong Gravitational Lenses in the DES and DECaLS Fields Selected Using Convolutional Neural Networks
The AGEL Survey: Spectroscopic Confirmation of Strong Gravitational Lenses in the DES and DECaLS Fields Selected Using Convolutional Neural Networks
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DOI：
10.3847/1538-3881/ac7da2
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发表时间：
2022-05
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影响因子：
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通讯作者：
K. Tran;A. Harshan;K. Glazebrook;Keerthi Vasan G. C.;T. Jones;C. Jacobs;G. Kacprzak;T. Barone
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文献类型：
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作者：
K. Tran;A. Harshan;K. Glazebrook;Keerthi Vasan G. C.;T. Jones;C. Jacobs;G. Kacprzak;T. Barone
我们目前的光谱确认候选人强引力透镜使用凯克天文台和甚大望远镜作为我们的ASTRO 3D星系演化与透镜（AGEL）调查的一部分。我们证实，（1）使用卷积神经网络（CNN）的搜索方法与目视检查成功地识别了强引力透镜，（2）由于DECam的更深和更高分辨率的成像与光谱学的结合，透镜相对于现有的调查具有更高的红移。我们从DES和DECaLS成像领域的目录中选择了77个系统，测量了104个红移（r ≤ 22 mag）。结合我们的研究结果与已发表的红移，我们提出了68个镜头的红移，并建立了基于CNN的搜索是非常有效的用于未来的成像调查，成功率至少为88%（定义为68/77）。我们报道了53个偏转器和光源都有光谱红移（z src > z defl）的强透镜和15个偏转器（z defl > 0.21）或光源（z src ≥ 1.34）有光谱红移的强透镜。对于68个透镜，偏转器和源的平均红移和标准偏差分别为0.58 ± 0.14和1.92 ± 0.59，相应的红移范围为z defl = 0.21-0.89和z src = 0.88-3.55。AGEL系统包括41个z defl ≥ 0.5的偏转器，这些偏转器非常适合后续研究，以跟踪质量密度分布如何随红移而演变。我们与AGEL的目标是在光谱上确认100个强引力透镜，这些透镜全年都可以从两个半球观察到。AGEL巡天是一个完善自动化全天空搜索和解决天体物理学和宇宙学中一系列问题的资源。
We present spectroscopic confirmation of candidate strong gravitational lenses using the Keck Observatory and Very Large Telescope as part of our ASTRO 3D Galaxy Evolution with Lenses (AGEL) survey. We confirm that (1) search methods using convolutional neural networks (CNNs) with visual inspection successfully identify strong gravitational lenses and (2) the lenses are at higher redshifts relative to existing surveys due to the combination of deeper and higher-resolution imaging from DECam and spectroscopy spanning optical to near-infrared wavelengths. We measure 104 redshifts in 77 systems selected from a catalog in the DES and DECaLS imaging fields (r ≤ 22 mag). Combining our results with published redshifts, we present redshifts for 68 lenses and establish that CNN-based searches are highly effective for use in future imaging surveys with a success rate of at least 88% (defined as 68/77). We report 53 strong lenses with spectroscopic redshifts for both the deflector and source (z src > z defl), and 15 lenses with a spectroscopic redshift for either the deflector (z defl > 0.21) or source (z src ≥ 1.34). For the 68 lenses, the deflectors and sources have average redshifts and standard deviations of 0.58 ± 0.14 and 1.92 ± 0.59 respectively, and corresponding redshift ranges of z defl = 0.21–0.89 and z src = 0.88–3.55. The AGEL systems include 41 deflectors at z defl ≥ 0.5 that are ideal for follow-up studies to track how mass density profiles evolve with redshift. Our goal with AGEL is to spectroscopically confirm ∼100 strong gravitational lenses that can be observed from both hemispheres throughout the year. The AGEL survey is a resource for refining automated all-sky searches and addressing a range of questions in astrophysics and cosmology.