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We aim to determine the most effective approach for estimating uncertainties in quasar photo-$z$ and to evaluate the ability of different models to reconstruct the true redshift distribution under varying data quality. We use photometric…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-23 Kacper Drabicki , Szymon J. Nakoneczny , Maciej Bilicki

We present a determination of the effects of including galaxy morphological parameters in photometric redshift estimation with an artificial neural network method. Neural networks, which recognize patterns in the information content of data…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 J. Singal , M. Shmakova , B. Gerke , R. L. Griffith , J. Lotz

Accurate and reliable photometric redshift determination is one of the key aspects for wide-field photometric surveys. Determination of photometric redshift for galaxies, has been traditionally solved by use of machine-learning and…

Instrumentation and Methods for Astrophysics · Physics 2025-07-18 M. Garcia-Fernandez

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

The aim of this paper is to investigate ways to optimize the accuracy of photometric redshifts for a SNAP like mission. We focus on how the accuracy of the photometric redshifts depends on the magnitude limit and signal-to-noise ratio,…

Measuring distances of cosmological sources such as galaxies, stars and quasars plays an increasingly critical role in modern cosmology. Obtaining the optical spectrum and consequently calculating the redshift as a distance indicator could…

Astrophysics of Galaxies · Physics 2022-01-13 Aidin Momtaz , Mohammad Hossein Salimi , Soroush Shakeri

The application of artificial neural networks (ANNs) for the estimation of HI gas mass fraction (\fgas) is investigated, based on a sample of 13,674 galaxies in the Sloan Digital Sky Survey (SDSS) with HI detections or upper limits from the…

Astrophysics of Galaxies · Physics 2016-12-07 Hossen Teimoorinia , Sara L. Ellison , David R. Patton

The estimation of spectroscopic and photometric redshifts (spec-z and photo-z) is crucial for future cosmological surveys. It can directly affect several powerful measurements of the Universe, e.g. weak lensing and galaxy clustering. In…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-05 Xingchen Zhou , Yan Gong , Xian-Min Meng , Xin Zhang , Ye Cao , Xuelei Chen , Valeria Amaro , Zuhui Fan , Liping Fu

Measuring the redshift of active galactic nuclei (AGNs) requires the use of time-consuming and expensive spectroscopic analysis. However, obtaining redshift measurements of AGNs is crucial as it can enable AGN population studies, provide…

We present a scheme based on artificial neural networks (ANN) to estimate the line-of-sight velocities of individual galaxies from an observed redshift-space galaxy distribution. We find an estimate of the peculiar velocity at a galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-09 Hongxiang Chen , Jie Wang , Tianxiang Mao , Juntao Ma , Yuxi Meng , Baojiu Li , Yan-Chuan Cai , Mark Neyrinck , Bridget Falck , Alexander S. Szalay

Accurate photometric redshift estimation is critical for observational cosmology, especially in large-scale surveys where spectroscopic measurements are impractical. Traditional approaches include template fitting and machine learning, each…

Instrumentation and Methods for Astrophysics · Physics 2026-04-15 Jonas Chris Ferrao , Dickson Dias , Pranav Naik , Glory D'Cruz , Anish Naik , Siya Khandeparkar , Manisha Gokuldas Fal Dessai

Photometric redshift estimation plays a crucial role in modern cosmological surveys for studying the universe's large-scale structures and the evolution of galaxies. Deep learning has emerged as a powerful method to produce accurate…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-04 R. Ait-Ouahmed , S. Arnouts , J. Pasquet , M. Treyer , E. Bertin

We present an updated version of MegaZ-LRG (Collister et al.,(2007)) with photometric redshifts derived with the neural network method, ANNz as well as five other publicly available photo-z codes (HyperZ, SDSS, Le PHARE, BPZ and ZEBRA) for…

Astrophysics · Physics 2013-01-21 Filipe B. Abdalla , Manda Banerji , Ofer Lahav , Valery Rashkov

For more that seventy years, the measurements of fluxes of galaxies at different wavelengths and derived colours have been used to estimate their corresponding cosmological distances. From the fields of galaxy and AGN evolution to precision…

Astrophysics of Galaxies · Physics 2018-06-06 Mara Salvato , Olivier Ilbert , Ben Hoyle

The Early Data Release from the Sloan Digital Sky survey provides one of the largest multicolor photometric catalogs currently available to the astronomical community. In this paper we present the first application of photometric redshifts…

We present a new approach, kernel regression, to determine photometric redshifts for 399,929 galaxies in the Fifth Data Release of the Sloan Digital Sky Survey (SDSS). In our case, kernel regression is a weighted average of spectral…

Astrophysics · Physics 2009-11-13 D. Wang , Y. X. Zhang , C. Liu , Y. H. Zhao

Improving distance measurements in large imaging surveys is a major challenge to better reveal the distribution of galaxies on a large scale and to link galaxy properties with their environments. Photometric redshifts can be efficiently…

Deep Learning models have been increasingly exploited in astrophysical studies, yet such data-driven algorithms are prone to producing biased outputs detrimental for subsequent analyses. In this work, we investigate two major forms of…

Instrumentation and Methods for Astrophysics · Physics 2022-06-15 Q. Lin , D. Fouchez , J. Pasquet , M. Treyer , R. Ait Ouahmed , S. Arnouts , O. Ilbert

The accuracy of galaxy photometric redshift (photo-$z$) can significantly affect the analysis of weak gravitational lensing measurements, especially for future high-precision surveys. In this work, we try to extract photo-$z$ information…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-11 Xingchen Zhou , Yan Gong , Xian-Min Meng , Ye Cao , Xuelei Chen , Zhu Chen , Wei Du , Liping Fu , Zhijian Luo

Galaxy photometric redshift (photo-$z$) is crucial in cosmological studies, such as weak gravitational lensing and galaxy angular clustering measurements. In this work, we try to extract photo-$z$ information and construct its probability…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-16 Xingchen Zhou , Yan Gong , Xian-Min Meng , Xuelei Chen , Zhu Chen , Wei Du , Liping Fu , Zhijian Luo