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Noisy distance estimates associated with photometric rather than spectroscopic redshifts lead to a mis-estimate of the luminosities, and produce a correlated mis-estimate of the sizes. We consider a sample of early-type galaxies from the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Graziano Rossi , Ravi K. Sheth , Changbom Park

The uncertainty in the redshift distributions of galaxies has a significant potential impact on the cosmological parameter values inferred from multi-band imaging surveys. The accuracy of the photometric redshifts measured in these surveys…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-05 Augusta Abrahamse , Lloyd Knox , Samuel Schmidt , Paul Thorman , J. Anthony Tyson , Hu Zhan

We apply Monte Carlo Markov Chain (MCMC) methods to large-scale simulations of galaxy formation in a LambdaCDM cosmology in order to explore how star formation and feedback are constrained by the observed luminosity and stellar mass…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Bruno Henriques , Simon White , Peter Thomas , Raul Angulo , Qi Guo , Gerard Lemson , Volker Springel

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 explore the enhanced self-calibration of photometric galaxy redshift distributions, $n(z)$, through the combination of up to six two-point functions. Our $\rm 3\times2pt$ configuration is comprised of photometric shear, spectroscopic…

We present an improved photometric redshift estimator code, CuBAN$z$, that is publicly available at https://goo.gl/fpk90V}{https://goo.gl/fpk90V. It uses the back propagation neural network along with clustering of the training set, which…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-23 Saumyadip Samui , Shanoli Samui Pal

It has been recently shown that a powerful way to constrain cosmological parameters from galaxy redshift surveys is to train graph neural networks to perform field-level likelihood-free inference without imposing cuts on scale. In…

We present a deep BVrIK multicolor catalog of galaxies in the field of the high redshift (z=4.7) quasar BR 1202-0725. Reliable colors have been measured for galaxies selected down to R=25. The choice of the optical filters has been…

Astrophysics · Physics 2009-10-30 E. Giallongo , S. D'Odorico , A. Fontana , S. Cristiani , E. Egami , E. Hu , R. G. McMahon

Approximate Bayesian Computation (ABC) is a method to obtain a posterior distribution without a likelihood function, using simulations and a set of distance metrics. For that reason, it has recently been gaining popularity as an analysis…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-28 Tomasz Kacprzak , Jörg Herbel , Adam Amara , Alexandre Réfrégier

Accurate estimation of photometric redshifts (photo-$z$s) is crucial for cosmological surveys. Various methods have been developed for this purpose, such as template fitting methods and machine learning techniques, each with its own…

We explore the effects of incorporating redshift uncertainty into measurements of galaxy clustering and cross-correlations of galaxy positions and cosmic microwave background (CMB) lensing maps. We use a simple Gaussian model for a redshift…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-26 Ross Cawthon

In this study we present a new experimental design using clustering-based redshift inference to measure the evolving galaxy luminosity function (GLF) spanning 5.5 decades from $L \sim 10^{11.5}$ to $ 10^6 ~ \mathrm{L}_\odot$. We use data…

"Approximate Bayesian Computation" (ABC) represents a powerful methodology for the analysis of complex stochastic systems for which the likelihood of the observed data under an arbitrary set of input parameters may be entirely…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 E. Cameron , A. N. Pettitt

To address the challenge of estimating redshifts when only single-band images are available, this study introduces a deep learning model named ViT-MDNz. Leveraging robust statistical priors learned from large-scale data concerning the…

Astrophysics of Galaxies · Physics 2026-02-27 Zhijian Luo , Yangyang Li , Jianzhen Chen , Qishen Cao , Duo Cao , Shaohua Zhang , Hubing Xiao , Chenggang Shu

Only by incorporating various forms of feedback can theories of galaxy formation reproduce the present-day luminosity function of galaxies. It has also been argued that such feedback processes might explain the counter-intuitive behaviour…

Astrophysics · Physics 2009-11-13 M. J. Stringer , A. J. Benson , K. Bundy , R. S. Ellis , E. L. Quetin

We develop a novel method to explore the galaxy-halo connection using the galaxy imaging surveys by modeling the projected two-point correlation function measured from the galaxies with reasonable photometric redshift measurements. By…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-17 Zhaoyu Wang , Haojie Xu , Xiaohu Yang , Y. P. Jing , Hong Guo , Zheng Zheng , Ying Zu , Zhigang Li , Chengze Liu

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

Modern galaxy surveys demand extensive survey volumes and resolutions surpassing current dark matter-only simulations' capabilities. To address this, many methods employ effective bias models on the dark matter field to approximate object…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-08 Daniel Forero-Sánchez , Francisco-Shu Kitaura , Francesco Sinigaglia , Jose María Coloma-Nadal , Jean-Paul Kneib

Likelihood-free inference provides a rigorous approach to preform Bayesian analysis using forward simulations only. The main advantage of likelihood-free methods is its ability to account for complex physical processes and observational…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Sut-Ieng Tam , Keiichi Umetsu , Adam Amara

We present results exploring the role that probabilistic deep learning models can play in cosmology from large-scale astronomical surveys through photometric redshift (photo-z) estimation. Photo-z uncertainty estimates are critical for the…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-20 Evan Jones , Tuan Do , Bernie Boscoe , Jack Singal , Yujie Wan , Zooey Nguyen