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Related papers: Galaxy-Galaxy Blending in SPHEREx Survey Data

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Standard models for deep galaxy counts are based on luminosity functions (LF) with relatively flat faint end ($\alpha\sim-1.0$). Galaxy counts in the B--band exceed the prediction of such models by a factor of 2 to more than 5, forcing the…

Astrophysics · Physics 2015-06-24 P. Saracco , G. Chincarini , A. Iovino

The number density and correlation function of galaxies are two key quantities to characterize the distribution of the observed galaxy population. High-$z$ spectroscopic surveys, which usually involve complex target selection and are…

Astrophysics of Galaxies · Physics 2024-02-05 Jiacheng Meng , Cheng Li , Houjun Mo , Yangyao Chen , Kai Wang

We study the effect of magnification in the Dark Energy Survey Year 3 analysis of galaxy clustering and galaxy-galaxy lensing, using two different lens samples: a sample of Luminous red galaxies, redMaGiC, and a sample with a…

The new generation of deep photometric surveys requires unprecedentedly precise shape and photometry measurements of billions of galaxies to achieve their main science goals. At such depths, one major limiting factor is the blending of…

Stage-IV dark energy wide-field surveys, such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), will observe an unprecedented number density of galaxies. As a result, the majority of imaged galaxies will visually…

Instrumentation and Methods for Astrophysics · Physics 2026-03-13 Ismael Mendoza , Derek Hansen , Runjing Liu , Zhe Zhao , Ziteng Pang , Axel Guinot , Camille Avestruz , Jeffrey Regier , the LSST Dark Energy Science Collaboration

Weak gravitational lensing is a powerful probe for constraining cosmological parameters, but its success relies on accurate shear measurements. In this paper, we use image simulations to investigate how a joint analysis of high-resolution…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-22 Shiyang Zhang , Shun-Sheng Li , Henk Hoekstra

We investigate the impact of hierarchical galaxy merging on the statistics of gravitational lensing of distant sources. Since no definite theoretical predictions for the merging history of luminous galaxies exist, we adopt a parametrized…

Astrophysics · Physics 2019-08-17 Hans-Walter Rix , Dan Maoz , Edwin L. Turner , Masataka Fukugita

As the first paper in a series on the study of the galaxy-galaxy lensing from Sloan Digital Sky Survey Data Release 7 (SDSS DR7), we present our image processing pipeline that corrects the systematics primarily introduced by the Point…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-15 Wentao Luo , Xiaohu Yang , Jun Zhang , Dylan Tweed , Liping Fu , H. J. Mo , Frank C. van den Bosch , Chenggang Shu , Ran Li , Nan Li , Xiangkun Liu , Chuzhong Pan , Yiran Wang , Mario Radovich

Increasingly large areas in cosmic shear surveys lead to a reduction of statistical errors, necessitating to control systematic errors increasingly better. One of these systematic effects was initially studied by Hartlap et al. in 2011,…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-14 Eray Genc , Peter Schneider , Sandra Unruh , Tim Schrabback

In Stage-IV imaging surveys, a significant amount of the cosmologically useful information is due to sources whose images overlap with those of other sources on the sky. The cosmic shear signal is primarily encoded in the estimated shapes…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-04 Javier Sanchez , Ismael Mendoza , David P. Kirkby , Patricia R. Burchat

We compile a sample of spectroscopically- and photometrically-selected cluster galaxies from four high-redshift galaxy clusters ($1.59 < z < 1.71$) from the Spitzer Adaptation of the Red-Sequence Cluster Survey (SpARCS), and a comparison…

Recent observational evidence suggests that the coarse angular resolution ($\sim20"$ FWHM) of single-dish telescopes at sub-mm wavelengths has biased the observed galaxy number counts by blending together the sub-mm emission from multiple…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 William I. Cowley , Cedric G. Lacey , Carlton M. Baugh , Shaun Cole

We estimate the evolution of the galaxy-galaxy merger fraction for $M_\star>10^{10.5}M_\odot$ galaxies over $0.25<z<1$ in the $\sim$18.6 deg$^2$ deep CLAUDS+HSC-SSP surveys. We do this by training a Random Forest Classifier to identify…

Astrophysics of Galaxies · Physics 2021-06-09 Nathalie Thibert , Marcin Sawicki , Andy Goulding , Stephane Arnouts , Jean Coupon , Stephen Gwyn

SPHEREx is a NASA mission designed to perform an all-sky spectroscopic survey in the 0.75 - 5 $\mu$m wavelength range. Its primary science objectives are to investigate: (1) inflationary cosmology, (2) the history of galaxy formation, and…

We present a novel approach to analyzing astronomical spectral survey data using our non-linear extension of an online dictionary learning algorithm. Current and upcoming surveys such as SPHEREx will use spectral data to build a 3D map of…

Instrumentation and Methods for Astrophysics · Physics 2023-11-28 Sean Bryan , Ayan Barekzai , Delondrae Carter , Philip Mauskopf , Julian Mena , Danielle Rivera , Abel S. Uriarte , Pao-Yu Wang

Low Surface-Brightness (LSB) galaxies are severely underrepresented in surveys used to define the local luminosity function (LF), but could it in principle be detected in deep surveys. To explore the possible contribution of such objects to…

Astrophysics · Physics 2009-10-22 Henry C. Ferguson , Stacy S. McGaugh

The Galaxy Evolution Explorer (GALEX) satellite performed the first and only large-area UV survey, which in tandem with the Sloan Digital Sky Survey (SDSS) has facilitated modeling of the spectral energy distributions (SEDs) of low-redshift…

Astrophysics of Galaxies · Physics 2023-07-27 Chandler Osborne , Samir Salim , Mederic Boquien , Mark Dickinson , Stephane Arnouts

Gravitational lensing magnification modifies the observed spatial distribution of galaxies and can severely bias cosmological probes of large-scale structure if not accurately modelled. Standard approaches to modelling this magnification…

The Spectro Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx) is conducting the first all-sky near infrared spectral survey spanning 0.75 to 5.0um with resolving power R~35 to 130. Linear…