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Related papers: Measuring Redshift-Space Distortions using Photome…

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Photometric redshifts (photo-$z$'s) are crucial for the cosmology, galaxy evolution, and transient science drivers of next-generation imaging facilities like the Euclid Mission, the Rubin Observatory, and the Nancy Grace Roman Space…

Astrophysics of Galaxies · Physics 2025-12-03 Emma R. Moran , Brett H. Andrews , Jeffrey A. Newman , Biprateep Dey

We study the applicability of several galaxy environment measures (n^th-nearest-neighbor distance, counts in an aperture, and Voronoi volume) within deep redshift surveys. Mock galaxy catalogs are employed to mimic representative…

The 2dF Galaxy Redshift Survey (2dFGRS) has already measured over 220,000 redshifts of nearby (z ~0.1) galaxies. It allows us to estimate fundamental cosmological parameters and to subdivide the survey into subsets according to the galaxy…

Astrophysics · Physics 2007-05-23 Ofer Lahav , the 2dFGRS team

Accurate estimation of photometric redshifts (photo-$z$) is crucial in studies of both galaxy evolution and cosmology using current and future large sky surveys. In this study, we employ Random Forest (RF), a machine learning algorithm, to…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-27 Junhao Lu , Zhijian Luo , Zhu Chen , Liping Fu , Wei Du , Yan Gong , Yicheng Li , Xian-Min Meng , Zhirui Tang , Shaohua Zhang , Chenggang Shu , Xingchen Zhou , Zuhui Fan

Galaxy redshift surveys are one of the pillars of the current standard cosmological model and remain a key tool in the experimental effort to understand the origin of cosmic acceleration. To this end, the next generation of surveys aim at…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-30 L. Guzzo , J. Bel , D. Bianchi , C. Carbone , B. R. Granett , A. J. Hawken , F. G. Mohammad , A. Pezzotta , S. Rota , M. Zennaro

We present a method to refine photometric redshift galaxy catalogs by comparing their color-space matching with overlapping spectroscopic calibration data. We focus on cases where photometric redshifts (photo-$z$) are estimated empirically.…

We suggest to use the observationally measured and theoretically justified correlation between size and rotational velocity of galactic discs as a viable method to select a set of high redshift standard rods which may be used to explore the…

We present a supervised neural network approach to the determination of photometric redshifts. The method was tuned to match the characteristics of the Sloan Digital Sky Survey and it exploits the spectroscopic redshifts provided by this…

In this Letter we point out that redshift surveys can break the degeneracy between the galaxy bias, the power spectrum normalization, \sigma_{8,0} and the growth factor, without the need for external information by using a simple and rather…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Cinzia Di Porto , Luca Amendola , Enzo Branchini

A new method is developed for estimating photometric redshifts, using realistic template SEDs, extending over four decades in wavelength (i.e from 0.05 $\mu m$ to 1 mm). The SEDs are constructed for four different spectral types of galaxies…

Astrophysics · Physics 2007-05-23 B. Mobasher , P. Mazzei

Measurements of redshift space distortions (RSD) provide a means to test models of gravity on large-scales. We use mock galaxy catalogues constructed from large N-body simulations of standard and modified gravity models to measure galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 César Hernández-Aguayo , Jiamin Hou , Baojiu Li , Carlton M. Baugh , Ariel G. Sánchez

We improve the accuracy of photometric redshifts by including low-resolution spectral data from the G102 grism on the Hubble Space Telescope, which assists in redshift determination by further constraining the shape of the broadband…

(abridged) The evolution of galaxy clustering from z=0 to z=4.5 is analyzed using the angular correlation function and the photometric redshift distribution of galaxies brighter than I_{AB}\le 28.5 in the HDF North. The reliability of the…

We investigate the expected accuracy of redshifts that can be obtained using low-resolution spectroscopic (medium-band) data from the 7-Dimensional Sky Survey (7DS). By leveraging 40 densely sampled filters with widths of full width at half…

Astrophysics of Galaxies · Physics 2025-10-01 Eunhee Ko , Myungshin Im , Yujin Yang , Ji Hoon Kim , Seong-Kook Lee , Gregory S. -H. Paek

Measuring environment for large numbers of distant galaxies is still an open problem, for which we need galaxy positions and redshifts. Photometric redshifts are more easily available for large numbers of galaxies, but at the price of…

Astrophysics of Galaxies · Physics 2016-01-06 Nicola Malavasi , Lucia Pozzetti , Olga Cucciati , Sandro Bardelli , Andrea Cimatti

Redshift space distortions in galaxy clustering offer a promising technique for probing the growth rate of structure and testing dark energy properties and gravity. We consider the issue of to what accuracy they need to be modeled in order…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-19 Eric V. Linder , Johan Samsing
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