This paper seeks to test if the large-scale galaxy distribution can be characterized as a fractal system. Tools appropriate for describing galaxy fractal structures with a single fractal dimension $D$ in relativistic settings are developed and applied to the UltraVISTA galaxy survey. A graph of volume-limited samples corresponding to the redshift limits in each redshift bins for absolute magnitude is presented. Fractal analysis using the standard $Λ$CDM cosmological model is applied to a reduced subsample in the range $0.1\le z \le 4$, and the entire sample within $0.1\le z\le 6$. Three relativistic distances are used, the luminosity distance $d_L$, redshift distance $d_z$ and galaxy area distance $d_G$, because for data at $z\gtrsim 0.3$ relativistic effects are such that for the same $z$ these distance definitions yield different values. The results show two consecutive and distinct redshift ranges in both the reduced and complete samples where the data behave as a single fractal galaxy structure. For the reduced subsample we found that the fractal dimension is $D=\left(1.58\pm0.20\right)$ for $z<1$, and $D=\left(0.59\pm0.28\right)$ for $1\le z\le 4$. The complete sample yielded $D=\left(1.63\pm0.20\right)$ for $z<1$ and $D=\left(0.52\pm0.29\right)$ for $1\le z\le6$. These results are consistent with those found by Conde-Saavedra et al. (2015; arXiv:1409.5409v1), where a similar analysis was applied to a much more limited survey at equivalent redshift depths, and suggest that either there are yet unclear observational biases causing such decrease in the fractal dimension, or the galaxy clustering was possibly more sparse and the universe void dominated in a not too distant past.
A Strongly-Lensed Massive Ultra-Compact Quiescent Galaxy at z ~ 2.4 in the COSMOS/UltraVISTA Field
We report the discovery of a massive ultra-compact quiescent galaxy that has been strongly-lensed into multiple images by a foreground galaxy at z = 0.960. This system was serendipitously discovered as a set of extremely Ks-bright high-redshift galaxies with red J - Ks colors using new data from the UltraVISTA YJHKs near-infrared survey. The system was also previously identified as an optically-faint lens/source system using the COSMOS ACS imaging by Faure et al. (2008, 2011). Photometric redshifts for the three brightest images of the source galaxy determined from twenty-seven band photometry…
The Evolution of the Stellar Mass Functions of Star-Forming and Quiescent Galaxies to z = 4 from the COSMOS/UltraVISTA Survey
我们目前的恒星质量函数(SMF)的恒星形成和静止星系z = 4使用的样本中的95 675个星系的COSMOS/UltraVISTA字段的测量。从DR 1 UltraVISTA K_{s}波段成像中选择了源,该波段成像覆盖了宽区域(1.62 deg^2)到显著深度(K_{s,tot} = 23.4)的独特组合。合并后的星族的SMF与先前的测量结果非常一致,表明宇宙的恒星质量密度在z = 0.75、2.0和3.5时分别只有当前值的50%、10%和1%。静止的星族驱动了大部分的整体增长,这些星系的恒星质量密度从z = 3.5开始增加了2.71^{+0.93}_{-0.22} dex。在z > 2.5时,恒星形成星系在所有恒星质量的总SMF中占主导地位,尽管静止星系的非零种群持续到z = 4。K_{s}选择的恒星形成星系SMF与紫外选择的SMF在2.5 < z 3.5的比较< 4 show reasonable agreement and suggests UV-selected samples are representative of the majority of the stellar mass density at z >。我们估计的平均质量增长的个别星系选择星系在固定的累积数密度。在z = 0.3时Log(M_{*} / M_{sun})= 11.5的星系,平均质量自z …
This paper discusses if large scale galaxy distribution samples containing almost one million objects can be characterized as fractal systems. The analysis performed by Teles et al. (2021; arXiv:2012.07164) on the UltraVISTA DR1 survey is extended here to the SPLASH and COSMOS2015 catalogs, hence adding 750k new galaxies with measured redshifts to the studied samples. The standard $Λ$CDM cosmology having $H_0=(70\pm5)$ km/s/Mpc and number density tools required for describing these galaxy distributions as single fractal systems with dimension $D$ are adopted. We use the luminosity distance $d_…
Spitzer bright, UltraVISTA faint sources in COSMOS: the contribution to the overall population of massive galaxies at z=3-7
我们分析了UltraVISTA超深COSMOS场上574个斯皮策4.5微米选择星系的样本,[4.5] <23 and Ks_auto>24(AB)。我们的目标是调查这些中红外明亮,近红外暗淡的来源是否对红移z>=3的大质量星系的总体人口有显着贡献。通过使用多达30个光度带进行光谱能量分布(SED)分析,我们已经确定了我们的样品峰的红移分布在红移z~2.5-3.0,约32%的星系位于z>=3。我们研究了在高红移下这些源对星系恒星质量函数(GSMF)的贡献。我们发现,[4.5]<23,Ks_auto>24的星系对先前在3=<z<4时Ks_auto<24的源所确定的GSMF产生的变化可以忽略不计,但在4=<z<5时它们的贡献更重要,占恒星质量Mst>~6 x 10^10 Msun的星系的>~50%。我们还将GSMF限制在z>=5时的最高质量端(Mst>~2 x 10^11 Msun)。根据它们在5=<z<6处的存在,以及在较高红移处的实际不存在,我们可以相当精确地确定第一个最大质量星系出现的时刻发生在z~6和z~5之间的约0.2 Gyr的时间内。或者,如果非常大的星系在宇宙时间的早期就存在,它们应该被大量的尘埃遮蔽,从而超出当前大面积深近红外探测的探测极限。
Fractal dimension of the cosmic web with different galaxy types
Chemistry Institute, Universidade Estadual de Campinas(坎皮纳斯州立大学化学学院);Geosciences Institute, Universidade Federal do Rio de Janeiro(里约热内卢联邦大学地球科学研究所);Faculty of Animal Science and Food Engineering, Universidade de São Paulo(圣保罗大学动物科学与食品工程学院);Division of Physics, Mathematics and Astronomy, California Institute of Technology(加州理工学院物理、数学与天文学部);Physics Institute, Universidade Federal do Rio de Janeiro(里约热内卢联邦大学物理研究所);Instituto de Astrofísica de La Plata, CONICET-UNLP(拉普拉塔天文物理研究所,阿根廷国家科学研究委员会-拉普拉塔国立大学);Institute of Astronomy, Geophysics, and Atmospheric Sciences, Universidade de São Paulo(圣保罗大学天文、地球物理与大气科学学院)
We use a large K-selected sample of 299,961 galaxies from the REFINE survey, consisting of a combination of data from three of the deepest near-infrared surveys: UKIDSS UDS, COSMOS/UltraVISTA and CFHTLS-D1/VIDEO, that were homogeneously reduced to obtain photometric redshifts and stellar masses. We detect 2588 candidate galaxy groups up to $z=3.15$ at $S/N>1.5$. We build a very pure ($>90\%$) sample of 448 candidate groups up to $z=2.5$ and study some of their properties. Cluster detection is done using the DElaunay TEssellation ClusTer IdentiFication with photo-z (DETECTIFz) algorithm that we…
In the coming decade, a new generation of massively multiplexed spectroscopic surveys, such as PFS, WAVES, and MOONS, will probe galaxies in the distant universe in vastly greater numbers than was previously possible. In this work, we generate mock catalogs for each of these three planned surveys to help quantify and optimize their scientific output. To assign photometry into the UniverseMachine empirical model, we develop the Calibrating Light: Illuminating Mocks By Empirical Relations (CLIMBER) procedure using UltraVISTA photometry. Using the published empirical selection functions for each …