Title: Deep R-band counts of z~3 Lyman break galaxy candidates with the LBT Show Chinese title

Title: z~3莱曼断裂星系候选者的深度R波段计数与LBT

Abstract: Aims. We present a deep multiwavelength imaging survey (UGR) in 3 different fields, Q0933, Q1623, and COSMOS, for a total area of ~1500arcmin^2. The data were obtained with the Large Binocular Camera on the Large Binocular Telescope. Methods. To select our Lyman break galaxy (LBG) candidates, we adopted the well established and widely used color-selection criterion (U-G vs. G-R). One of the main advantages of our survey is that it has a wider dynamic color range for U-dropout selection than in previous studies. This allows us to fully exploit the depth of our R-band images, obtaining a robust sample with few interlopers. In addition, for 2 of our fields we have spectroscopic redshift information that is needed to better estimate the completeness of our sample and interloper fraction. Results. Our limiting magnitudes reach 27.0(AB) in the R band (5\sigma) and 28.6(AB) in the U band (1\sigma). This dataset was used to derive LBG candidates at z~3. We obtained a catalog with a total of 12264 sources down to the 50% completeness magnitude limit in the R band for each field. We find a surface density of ~3 LBG candidates arcmin^2 down to R=25.5, where completeness is >=95% for all 3 fields. This number is higher than the original studies, but consistent with more recent samples. Show Chinese abstract

Abstract: 目标。 我们在三个不同的区域Q0933、Q1623和COSMOS进行了一项深度多波长成像调查（UGR），总区域约为1500平方弧分。 数据是通过大型双子望远镜上的大型双子相机获得的。 方法。 为了选择我们的Lyman断裂星系（LBG）候选者，我们采用了已建立且广泛使用的颜色选择标准（U-G vs. G-R）。 我们调查的主要优势之一是它在U脱落选择方面具有比之前研究更宽的动态颜色范围。 这使我们能够充分利用R波段图像的深度，获得一个干扰者较少的可靠样本。 此外，对于我们的两个区域，我们有光谱红移信息，这对于更好地估计样本的完整性和干扰者比例是必要的。 结果。 我们的极限星等在R波段达到27.0（AB）（5\sigma ），在U波段达到28.6（AB）（1\sigma ）。 该数据集用于推导z~3的LBG候选者。 我们获得了一个目录，每个区域在R波段的50%完整度星等下共有12264个源。 我们发现表面密度为约3个LBG候选者每平方弧分，直到R=25.5，在所有三个区域中完整性均大于等于95%。 这个数字高于原始研究，但与最近的样本一致。