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Related papers: Photometric Redshifts and Photometry Errors

200 papers

Flux magnification is an interesting complement to shear-based lensing measurements, especially at high redshift where sources are harder to resolve. One measures either changes in the source density (magnification bias) or in the shape of…

Astrophysics of Galaxies · Physics 2015-12-09 Hendrik Hildebrandt

Measurements of the Epoch of Reionization (EoR) 21-cm signal hold the potential to constrain models of reionization. In this paper we consider a reionization model with three astrophysical parameters namely (1) the minimum halo mass which…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-18 Abinash Kumar Shaw , Somnath Bharadwaj , Rajesh Mondal

It is known that the soft tail of the gamma-ray bursts' spectra show excesses from the exact power-law dependence. In this article we show that this departure can be detected in the peak flux ratios of different BATSE DISCSC energy…

Astrophysics · Physics 2009-11-07 Z. Bagoly , I. Csabai , A. Mészáros , P. Mészáros , I. Horváth , L. G. Balázs , R. Vavrek

The fluctuations produced during cosmic inflation may exhibit non-Gaussian characteristics that are imprinted in the large-scale structure of the Universe. This non-Gaussian imprint is an ultra-large scale signal that can be detected using…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-11 Mponeng Kopana , Sheean Jolicoeur , Roy Maartens

We discuss the construction of a photometric redshift catalogue of Luminous Red Galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS), emphasizing the principal steps necessary for constructing such a catalogue -- (i) photometrically…

We apply machine learning in the form of a nearest neighbor instance-based algorithm (NN) to generate full photometric redshift probability density functions (PDFs) for objects in the Fifth Data Release of the Sloan Digital Sky Survey (SDSS…

Generated images of score-based models can suffer from errors in their spatial means, an effect, referred to as a color shift, which grows for larger images. This paper investigates a previously-introduced approach to mitigate color shifts…

Machine Learning · Computer Science 2023-11-30 Katherine Deck , Tobias Bischoff

We study the impact of photometric signal to noise on the accuracy of derived structural parameters of unresolved star clusters using MCMC model fitting techniques. Star cluster images were simulated as a smooth surface brightness…

Astrophysics of Galaxies · Physics 2018-03-14 D. Narbutis , A. Bridžius , D. Semionov

The ability to constrain dark energy from the evolution of galaxy cluster counts is limited by the imperfect knowledge of cluster redshifts. Ongoing and upcoming surveys will mostly rely on redshifts estimated from broad-band photometry…

Astrophysics · Physics 2008-11-26 Marcos Lima , Wayne Hu

We examine the errors on counts in cells extracted from galaxy surveys. The measurement error, related to the finite number of sampling cells, is disentangled from the ``cosmic error'', due to the finiteness of the survey. Using the…

Astrophysics · Physics 2009-10-28 István Szapudi , Stéphane Colombi

We show how to enhance the redshift accuracy of surveys consisting of tracers with highly uncertain positions along the line of sight. Photometric surveys with redshift uncertainty delta_z ~ 0.03 can yield final redshift uncertainties of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Jens Jasche , Benjamin D. Wandelt

We studied the effect of primordial non-Gaussianity with varied bispectrum shapes on the number counts of signal-to-noise peaks in wide field cosmic shear maps. The two cosmological contributions to this particular weak lensing statistic,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 M. Maturi , C. Fedeli , L. Moscardini

Wide, deep photometric surveys require robust photometric redshift estimates (photo-z's) for studies of large-scale structure. These estimates depend critically on accurate photometry. We describe the improvements to the photometric…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Samuel J. Schmidt , Paul Thorman

We present a new training set for estimating empirical photometric redshifts of galaxies, which was created as part of the 2dFLenS project. This training set is located in a 700 sq deg area of the KiDS South field and is randomly selected…

The massive photometric data collected from multiple large-scale sky surveys offer significant opportunities for measuring distances of celestial objects by photometric redshifts. However, catastrophic failure is still an unsolved problem…

Instrumentation and Methods for Astrophysics · Physics 2016-05-25 Bo Han , Hongpeng Ding , Yanxia Zhang , Yongheng Zhao

Photometric redshift uncertainties are a major source of systematic error for ongoing and future photometric surveys. We study different sources of redshift error caused by choosing a suboptimal redshift histogram bin width and propose…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-02 Markus Michael Rau , Ben Hoyle , Kerstin Paech , Stella Seitz

We investigate the impact of spatial survey non-uniformity on the galaxy redshift distributions for forthcoming data releases of the Rubin Observatory Legacy Survey of Space and Time (LSST). Specifically, we construct a mock photometry…

The peculiar motion of an observer with respect to the CMB rest frame induces a deflection in the arrival direction of the observed photons (also known as CMB aberration) and a Doppler shift in the measured photon frequencies. As a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Riccardo Catena , Michele Liguori , Alessio Notari , Alessandro Renzi

The Wide Field Survey Telescope (WFST) is a dedicated time-domain multi-band ($u$, $g$, $r$, $i$, and $z$) photometric survey facility under construction. In this paper, we present a preliminary study that assesses the quality of…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-06 Yu Liu , Xiao-zhi Lin , Yong-quan Xue , Huynh Anh N. Le
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