Related papers: Cosmicflows-4
Context. Our Local Group of galaxies appears to be moving relative to the cosmic microwave background with the source of the peculiar motion still uncertain. While in the past this has been studied mostly using galaxies as distance…
With a large, unique spectroscopic survey in the fields of 28 galaxy-scale strong gravitational lenses, we identify groups of galaxies in the 26 adequately-sampled fields. Using a group finding algorithm, we find 210 groups with at least…
While much of the focus of observational cosmology is on the high redshift universe it is important not to neglect the very local universe as a source of cosmological information. The inner profiles and number counts of low mass halos have…
A major goal of contemporary astrophysics is understanding the origin of the most massive galaxies in the universe, particularly nearby ellipticals and spirals. Theoretical models of galaxy formation have existed for many decades, although…
We present a simple method for measuring cosmological bulk flows from large redshift surveys, based on the apparent dimming or brightening of galaxies due to their peculiar motion. It is aimed at estimating bulk flows of cosmological…
We describe the scientific motivation behind, and the methodology of, the Stanford Cluster Search (StaCS), a program to compile a catalog of optically selected clusters of galaxies at intermediate and high (0.3 < z < 1) redshifts. The…
We discuss a new method for inferring the stellar mass of a distant galaxy of known redshift based on the combination of a near-infrared luminosity and multi-band optical photometry. The typical uncertainty for field galaxies with I<22 in…
We present results of our wide-field redshift survey of galaxies in a 285 square degree region of the Shapley Supercluster (SSC), based on a set of 10529 velocity measurements (including 1201 new ones) on 8632 galaxies obtained from various…
We revisit the evolution of galaxy morphology in the COSMOS field over the redshift range $0.2\leq z \leq 1$, using a large and complete sample of 33,605 galaxies with a stellar mass of log($M_{\ast}$/M$_{\odot} )>9.5$ with significantly…
Using photometric data from the Dark Energy Survey and the Wide-field Infrared Survey Explorer, we estimate photometric redshifts for 105 million galaxies using the nearest-neighbour algorithm. From such a large data base, 151,244 clusters…
We present a new optical spectroscopic survey of 1777 'star-forming' ('SF') and 366 'non-star-forming' ('non-SF') galaxies at redshifts z < 1 (2143 in total), 22 AGN and 423 stars, observed by instruments such as DEIMOS, VIMOS and GMOS, in…
We present 118 new optical redshifts for galaxies in 12 clusters in the Horologium-Reticulum supercluster (HRS) of galaxies. For 76 galaxies, the data were obtained with the Dual Beam Spectrograph on the 2.3m telescope of the Australian…
Quickly growing computing facilities and an increasing number of extragalactic observations encourage the application of data-driven approaches to uncover hidden relations from astronomical data. In this work we raise the problem of…
We present the COSMOS Spectroscopic Redshift Compilation encompassing ~ 20 years of spectroscopic redshifts within a 10 deg$^2$ area centered on the 2 deg$^2$ COSMOS legacy field. This compilation contains 487,666 redshifts of 266,284…
We present the "C4 Cluster Catalog", a new sample of 748 clusters of galaxies identified in the spectroscopic sample of the Second Data Release (DR2) of the Sloan Digital Sky Survey (SDSS). The C4 cluster--finding algorithm identifies…
We present large-scale CCD images of a dozen low surface brightness objects in the vicinity of giant Sc galaxy NGC 6946, which have been found recently on POSS-II copies. Six of them: UGC 11583, kk251, kk252, kkr55, kkr56, and kkr59 are…
The number of galaxies at a given flux as a function of the redshift, $z$, is derived when the $z$-distance relation is non-standard. In order to compare different models, the same formalism is also applied to the standard cosmology. The…
The excess numbers of blue galaxies at faint magnitudes are a long-standing cosmological puzzle. We present new number-magnitude counts as a function of galactic morphology from the first deep fields of the Cycle 4 Hubble Space Telescope…
Galaxies located in the environment or on the line of sight towards gravitational lenses can significantly affect lensing observables, and can lead to systematic errors on the measurement of $H_0$ from the time-delay technique. We present…
We present data for 16 galaxies in the overdensity JKCS 041 at $z \simeq 1.80$ as part of the K-band Multi-Object Spectrograph (KMOS) Cluster Survey (KCS). With 20-hour integrations, we have obtained deep absorption-line spectra from which…