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Related papers: Photo-z Estimation: An Example of Nonparametric Co…

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Photometric redshifts play an important role as a measure of distance for various cosmological topics. Spectroscopic redshifts are only available for a very limited number of objects but can be used for creating statistical models. A broad…

Instrumentation and Methods for Astrophysics · Physics 2016-08-30 Kai Lars Polsterer , Antonio D'Isanto , Fabian Gieseke

Photometric redshift estimation is a key requirement for modern large-area surveys, where spectroscopic measurements are observationally prohibitive. Seyfert II galaxies provide a particularly challenging test case due to the combined…

Astrophysics of Galaxies · Physics 2026-04-23 Uzay Aydin

The James Webb Space Telescope (JWST) has enabled the discovery of a significant population of galaxies at z > 10. Our understanding of the astrophysical properties of these galaxies relies on fitting templates developed using models…

Instrumentation and Methods for Astrophysics · Physics 2026-04-09 Thorbjørn Clausen , Charles L. Steinhardt , Arden Shao , Gaurav Senthil Kumar

The estimation and utilization of photometric redshift probability density functions (photo-$z$ PDFs) has become increasingly important over the last few years and currently there exist a wide variety of algorithms to compute photo-$z$'s,…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-05 M. Carrasco Kind , R. J. Brunner

A method of obtaining approximate redshifts and spectral types of galaxies using a photometric system of six broad-bandpass filters is developed. The technique utilizes a smallest maximum difference approach rather than a least-squares…

Astrophysics · Physics 2009-10-30 Charles T. Liu , Richard F. Green

Cosmology and galaxy evolution studies with LSST, \Euclid, and {\it Roman}, will require accurate redshifts for the detected galaxies. In this study, we present improved photometric redshift estimates for galaxies using a template library…

Astrophysics of Galaxies · Physics 2020-08-06 Bomee Lee , Ranga-Ram Chary

In the era of large sky surveys, photometric redshifts (photo-z) represent crucial information for galaxy evolution and cosmology studies. In this work, we propose a new Machine Learning (ML) tool called Galaxy morphoto-Z with neural…

Estimating redshifts from broadband photometry is often limited by how accurately we can map the colors of galaxies to an underlying spectral template. Current techniques utilize spectrophotometric samples of galaxies or spectra derived…

Instrumentation and Methods for Astrophysics · Physics 2025-03-11 John Franklin Crenshaw , Andrew J. Connolly

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

As a means of better understanding the evolution of optically selected galaxies we consider the distribution of galaxies within the multicolor space $U$, $B_J$, $R_F$ and $I_N$. We find that they form an almost planar distribution out to…

Astrophysics · Physics 2008-11-26 A. J. Connolly , I. Csabai , A. S. Szalay , D. C. Koo , R. G. Kron , J. A. Munn

Accurate photometric redshift (photo-$z$) estimation is a key challenge in cosmology, as uncertainties in photo-$z$ directly limit the scientific return of large-scale structure and weak lensing studies, especially in upcoming Stage IV…

Instrumentation and Methods for Astrophysics · Physics 2025-12-10 Yiming Ren , Kwan Chuen Chan , Le Zhang , Yin Li , Haolin Zhang , Ruiyu Song , Yan Gong , Xian-Min Meng , Xingchen Zhou

We develop a new method which measures the projected density distribution w_p(r_p)n of photometric galaxies surrounding a set of spectroscopically-identified galaxies, and simultaneously the projected correlation function w_p(r_p) between…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Wenting Wang , Y. P. Jing , Cheng Li , Teppei Okumura , Jiaxin Han

We use photometric redshifts to analyse the effect of local environment on galaxy colours at redshifts z < 0.63 in the SDSS data release 6. We construct mock SDSS-DR6 catalogues using semi-analytic galaxies to study possible systematic…

Astrophysics · Physics 2009-11-13 Ana Laura O'Mill , Nelson Padilla , Diego Garcia Lambas

We perform an analysis of photometric redshifts estimated by using a non-representative training sets in magnitude space. We use the ANNz2 and GPz algorithms to estimate the photometric redshift both in simulations as well as in real data…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-12 J. D. Rivera , B. Moraes , A. I. Merson , S. Jouvel , F. B. Abdalla , M. C. B Abdalla

We investigate how well the redshift distributions of galaxies sorted into photometric redshift bins can be determined from the galaxy angular two-point correlation functions. We find that the uncertainty in the reconstructed redshift…

Astrophysics · Physics 2008-11-26 M. Schneider , L. Knox , H. Zhan , A. Connolly

We present a new method that simultaneously solves for cosmology and galaxy bias on non-linear scales. The method uses the halo model to analytically describe the (non-linear) matter distribution, and the conditional luminosity function…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Frank van den Bosch , Surhud More , Marcello Cacciato , Houjun Mo , Xiaohu Yang

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

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

Cosmological constraints from galaxy clusters rely on accurate measurements of the mass and internal structure of clusters. An important source of systematic uncertainty in cluster mass and structure measurements is the secure selection of…

Astrophysics of Galaxies · Physics 2016-10-12 Felicia Ziparo , Graham P. Smith , Nobuhiro Okabe , Chris P. Haines , Maria J. Pereira , Eiichi Egami