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The redshift-space bispectrum (three point statistics) of galaxies depends on the expansion rate, the growth rate, and geometry of the Universe, and hence can be used to measure key cosmological parameters. In a homogeneous Universe the…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Praful Gagrani , Lado Samushia

We investigate the performance of group finding algorithms that reconstruct galaxy groups from the positional information of tracer galaxies that are observed in redshift surveys carried out with multiplexed spectrographs. We use mock…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-28 Tobias J. Looser , Simon J. Lilly , Larry P. T. Sin , Bruno M. B. Henriques , Roberto Maiolino , Michele Cirasuolo

Measurements of the galaxy power spectrum contain a wealth of information about the Universe. Its optimal extraction is vital if we are to truly understand the micro-physical nature of dark matter and dark energy. In Smith & Marian (2015)…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 Robert E. Smith , Laura Marian

We present a two-dimensional (2-D) fitting algorithm (GALFIT, Version 3) with new capabilities to study the structural components of galaxies and other astronomical objects in digital images. Our technique improves on previous 2-D fitting…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Chien Y. Peng , Luis C. Ho , Chris D. Impey , Hans-Walter Rix

We present a new methodology to analyse in a comprehensive way large-scale and supernovae (or any other distance indicator) surveys. Our approach combines galaxy and supernova position and redshift data with supernova peculiar velocities,…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-31 Miguel Quartin , Luca Amendola , Bruno Moraes

We present a new method to classify the broad band optical-NIR spectral energy distributions (SEDs) of galaxies using three shape parameters (super-colours) based on a Principal Component Analysis of model SEDs. As well as providing a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Vivienne Wild , Omar Almaini , Michele Cirasuolo , Jim Dunlop , Ross McLure , Rebecca Bowler , Joao Ferreira , Emma Bradshaw , Robert Chuter , Will Hartley

Wide-area imaging surveys are one of the key ways of advancing our understanding of cosmology, galaxy formation physics, and the large-scale structure of the Universe in the coming years. These surveys typically require calculating…

Astrophysics of Galaxies · Physics 2020-10-07 P. W. Hatfield , I. A. Almosallam , M. J. Jarvis , N. Adams , R. A. A. Bowler , Z. Gomes , S. J. Roberts , C. Schreiber

The calibration of redshift distributions for photometric samples using spectroscopic surveys is plagued by the difficulty in modelling the selection functions of spectroscopic surveys. In this work, we analyse how these selection functions…

Instrumentation and Methods for Astrophysics · Physics 2022-07-19 Isaac McMahon , Markus Michael Rau , Rachel Mandelbaum

The angular power spectrum is a natural tool to analyse the observed galaxy number count fluctuations. In a standard analysis, the angular galaxy distribution is sliced into concentric redshift bins and all correlations of its harmonic…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 Guglielmo Faggioli , Konstantinos Tanidis , Stefano Camera

The next generation of proposed galaxy surveys will increase the number of galaxies with photometric redshifts by two orders of magnitude, drastically expanding both redshift range and detection threshold from the current state of the art.…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 A. E. Schulz

We describe an automated method for detecting clusters of galaxies in imaging and redshift galaxy surveys. The Adaptive Matched Filter (AMF) method utilizes galaxy positions, magnitudes, and---when available---photometric or spectroscopic…

Astrophysics · Physics 2010-11-04 Jeremy Kepner , Xiaohui Fan , Neta Bahcall , James Gunn , Robert Lupton , Guohong Xu

In Lima et al. 2008 we presented a new method for estimating the redshift distribution, N(z), of a photometric galaxy sample, using photometric observables and weighted sampling from a spectroscopic subsample of the data. In this paper, we…

Astrophysics · Physics 2010-03-18 Carlos E. Cunha , Marcos Lima , Hiroaki Oyaizu , Joshua Frieman , Huan Lin

Our view of the low-redshift Cosmic Web has been revolutionized by galaxy redshift surveys such as 6dFGS, SDSS and 2MRS. However, the trade-off between depth and angular coverage limits a systematic three-dimensional account of the entire…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-20 Maciej Bilicki , John A. Peacock , Thomas H. Jarrett , Michelle E. Cluver , Louise Steward

We study the dark matter halos of galaxies with galaxy-galaxy lensing using the COMBO-17 survey. This survey offers an unprecedented data set for studying lens galaxies at z=0.2-0.7 including redshift information and spectral classification…

Photometric redshifts are commonly used to measure the distribution of galaxies in large surveys. However, the demands of ongoing and future large-scale cosmology surveys place very stringent limits on the redshift performance that are…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-11 Philipp Sudek , Lucia F. de la Bella , Adam Amara , William G. Hartley

Low redshift surveys of galaxy peculiar velocities provide a wealth of cosmological information. We revisit the idea of extracting this information by directly measuring the redshift-space momentum power spectrum from such surveys. We…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-19 Cullan Howlett

[Abridged] Non-uniform sampling and gaps in sky coverage are common in galaxy redshift surveys, but these effects can degrade galaxy counts-in-cells and density estimates. We carry out a comparison of methods that aim to fill the gaps to…

The COSMOS field has been the subject of a wide range of observations, with a number of studies focusing on reconstructing the 3D dark matter density field. Typically, these studies have focused on one given method or tracer. In this paper,…

Determining the distribution of redshifts for galaxies in wide-field photometric surveys is essential for robust cosmological studies of weak gravitational lensing. We present the methodology, calibrated redshift distributions, and…

An observational program focused on the high redshift ($2<z<6$) Universe has the opportunity to dramatically improve over upcoming LSS and CMB surveys on measurements of both the standard cosmological model and its extensions. Using a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-04 Noah Sailer , Emanuele Castorina , Simone Ferraro , Martin White