An Optical Observational Cluster Mass Function at $z\sim1$ with the ORELSE Survey
D. Hung, B. C. Lemaux, R. R. Gal, A. R. Tomczak, L. M. Lubin, O. Cucciati, D. Pelliccia, L. Shen, O. Le Fèvre, G. Zamorani, P-F. Wu, D. D. Kocevski, C. D. Fassnacht, G. K. Squires
We present a new mass function of galaxy clusters and groups using optical/near-infrared wavelength spectroscopic and photometric data from the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) survey. At $z\sim1$, cluster mass function studies are rare regardless of wavelength and have never been attempted from an optical/near-infrared perspective. This work serves as a proof of concept that $z\sim1$ cluster mass functions are achievable without supplemental X-ray or Sunyaev-Zel'dovich (SZ) data. Measurements of the cluster mass function provide important contraints on cosmological parameters and are complementary to other probes. With ORELSE, a new cluster finding technique based on Voronoi tessellation Monte-Carlo (VMC) mapping, and rigorous purity and completeness testing, we have obtained $\sim$240 galaxy overdensity candidates in the redshift range $0.55<z<1.37$ at a mass range of $13.6<\log(M/M_{\odot})<14.8$. This mass range is comparable to existing optical cluster mass function studies for the local universe. Our candidate numbers vary based on the choice of multiple input parameters related to detection and characterization in our cluster finding algorithm, which we incorporated into the mass function analysis through a Monte-Carlo scheme. We find cosmological constraints on the matter density of $Ω_{m} = 0.250^{+0.104}_{-0.099}$ and on the amplitude of fluctuations of $σ_{8} = 1.150^{+0.260}_{-0.163}$. While our $Ω_{m}$ value is close to concordance, our $σ_{8}$ value is $\sim2σ$ higher because of the inflated observed number densities compared to theoretical mass function models owing to how our survey targeted overdense regions. With Euclid and several other large, unbiased optical surveys on the horizon, VMC mapping will enable optical/NIR cluster cosmology at redshifts much higher than what has been possible before.
Four New Observational $H(z)$ Data From Luminous Red Galaxies of Sloan Digital Sky Survey Data Release Seven
采用微分年龄法，利用Sloan数字巡天数据7（SDSS DR 7）中包含红移$0<z<0.4$的17832个亮红星系（LRGs）测量哈勃参数。利用全谱拟合软件UlySS，用单星族（SSP）模型对这些光谱进行了约简，并得到了我们所选样本的最佳年龄信息。随着年龄-红移关系的减小，获得了4个新的观测$H(z)$数据点，它们分别是$H(z)=69.0\pm19.6$ km s $^{-1}$ Mpc $^{-1}$ at $z=0.07$，$H(z)=68.6\pm26.2$ km s $^{-1}$ Mpc $^{-1}$ at $z=0.12$，$H(z)$ = $72.9\pm29.6$ km s $^{-1}$ Mpc $^{-1}$ at $z=0.2$和$H(z)$ = $88.8\pm36.6$ km s $^{-1}$ Mpc $^{-1}$ at $z=0.28$.结合其他21个OHD数据点，给出了平面和非平面$Λ$ CDM模型的约束性能。
The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey quasar sample: Testing observational systematics on the Baryon Acoustic Oscillation measurement
Cosmology with Peculiar Velocities: Observational Effects
在本文中，我们调查如何观测效应可能会偏离宇宙学的推论，从奇特的速度测量。具体来说，我们看看如何批量流量测量与理论预测相比。通常，整体流计算试图近似观察者周围球体中发生的流。使用Horizon Run 2模拟，我们表明，传统的整体流估计方法可能会高估整体流的大小，原因有两个：当测量几何形状不是球形时（数据不覆盖整个天空），以及当观测值采样不足时速度分布。我们的研究结果可以解释为什么几个整体流测量发现整体流的速度似乎比标准的ΛCDM宇宙学中预期的要大。我们建议一个不同的方法比较散装流量宇宙模型，其中理论预测为每个散装流量测量计算专门为该调查的几何形状和采样率。这意味着整体流量值在不同的测量之间是不可比的，但它们与宇宙学模型是可比的，这是更重要的衡量标准。
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Observational systematics and baryon acoustic oscillations in the correlation function
我们提出了重子声学振荡（BAO）尺度的测量确定的120万个大质量星系的红移0.2 < z < 0.75分布在9300平方度的集群，量化的红移空间关联函数。为了方便这些测量，我们定义，描述，并激励选择功能的SDSS III重子振荡光谱巡天（BOSS）的最终数据发布（DR 12）的星系。这包括观测足迹，图像质量和银河系消光的掩模，以及考虑调查成像和光谱部分固有的密度关系的权重。我们模拟了模拟星系样本中观察到的系统趋势，并证明它们对重子声学振荡（BAO）尺度测量没有影响，并且对恢复的统计不确定性有轻微的影响。我们在0.2 < z < 0.5，0.5 < z < 0.75和（重叠）0.4 < z < 0.6红移箱中测量横向和径向BAO距离测量。在每个红移箱，我们得到的精度是2.7%或更好的径向距离和1.6%或更好的横向距离。红移仓的组合表示径向距离的1.8%精度和横向距离的1.1%精度。本文是分析BOSS最终星系聚类数据集的一部分。这里提出的测量和可能性与Alam et al.（2016）中的其他测量和可能性相结合，以产生BOSS的最终宇宙学约束。
Observational Upper Bound on the Cosmic Abundances of Negative-mass Compact Objects and Ellis Wormholes from the Sloan Digital Sky Survey Quasar Lens Search
A Parametrized Galaxy Catalog Simulator For Testing Cluster Finding, Mass Estimation and Photometric Redshift Estimation in Optical and Near Infrared Surveys
Brane cosmology from observational surveys and its comparison with standard FRW cosmology
研究了膜上的几种暗能量模型。并在四维Friedmann-Robertson-Walker宇宙学框架下与相应的理论进行了比较。为了约束所考虑的模型的参数，最近的观测数据，包括SNIa视星等测量，重子声学振荡结果，哈勃参数演化数据和物质密度扰动。得到了远程平行理论中所谓的{ \it state finder}参数的显式公式，这可能有助于测试这些模型，并建立环量子宇宙学和膜宇宙学之间的联系。它的结论是，联合分析，因为这里开发的一个允许估计，在一个非常方便的方式，可能的偏差，从标准的弗里德曼-罗伯逊-沃克的真实宇宙宇宙学。
Dark Energy Survey Year 6 Results: improved mitigation of spatially varying observational systematics with masking for the MagLim++ lens sample
Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid（马德里自治大学理论物理研究所）；Laboratoire de physique des 2 infinis Irène Joliot-Curie, CNRS Université Paris-Saclay（巴黎萨克雷大学CNRS伊雷娜·约里奥-居里双无限物理实验室）；Ruhr University Bochum, Faculty of Physics and Astronomy, Astronomical Institute, German Centre for Cosmological Lensing（波鸿鲁尔大学物理与天文学院天体物理研究所德国宇宙学透镜中心）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Berkeley Center for Cosmological Physics, Department of Physics, University of California, Berkeley（加州大学伯克利分校物理系宇宙学物理中心）；Department of Physics and Astronomy, University of Waterloo（滑铁卢大学物理与天文系）；Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT)（能源、环境与技术研究中心）
Robust Measurement of Stellar Streams Around the Milky Way: Correcting Spatially Variable Observational Selection Effects in Optical Imaging Surveys
Harvard University（哈佛大学）；University of Wisconsin-Madison（威斯康星大学麦迪逊分校）；University of Washington（华盛顿大学）；Legacy Survey of Space and Time（时空遗产巡天）；University of Groningen（格罗宁根大学）；Fermi National Accelerator Laboratory（费米国家加速器实验室）；Kavli Institute for Cosmological Physics（卡弗里宇宙物理学研究所）
A Determination of the Intergalactic Redshift Dependent UV-Optical-NIR Photon Density Using Deep Galaxy Survey Data and the Gamma-ray Opacity of the Universe
