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Related papers: Photometric Redshifts with Copula Entropy

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Photometric redshifts (photo-$z$'s) will be crucial for studies of galaxy evolution, large-scale structure, and transients with the Nancy Grace Roman Space Telescope. Deep learning methods leverage pixel-level information from ground-based…

Instrumentation and Methods for Astrophysics · Physics 2026-05-14 Ashod Khederlarian , Brett H. Andrews , Jeffrey A. Newman , Tianqing Zhang , Biprateep Dey

We demonstrate that the design of the Sloan Digital Sky Survey (SDSS) filter system and the quality of the SDSS imaging data are sufficient for determining accurate and precise photometric redshifts (``photo-z''s) of quasars. Using a sample…

This paper reports the results obtained on the photometric redshifts measurement and accuracy, and cluster tomography in the ESO Distant Cluster Survey (EDisCS) fields. Photometric redshifts were computed using two independent codes (Hyperz…

The addition of deep near infrared images to the database provided by the HDF-S WFPC2 is essential to monitor the SEDs of the objects on a wide baseline and address a number of key issues including the total stellar content of baryonic…

Astrophysics · Physics 2009-11-07 S. Cristiani , S. Arnouts , A. Fontana , P. Saracco , E. Vanzella

The next generation of proposed galaxy surveys will increase the number of galaxies with photometric redshifts by two orders of magnitude, drastically expanding both redshift range and detection threshold from the current state of the art.…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 A. E. Schulz

We outline how redshift-space distortions (RSD) can be measured from the angular correlation function w({\theta}), of galaxies selected from photometric surveys. The natural degeneracy between RSD and galaxy bias can be minimized by…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 Ashley J Ross , Will J Percival , Martin Crocce , Anna Cabre , Enrique Gaztanaga

Handling big data has largely been a major bottleneck in traditional statistical models. Consequently, when accurate point prediction is the primary target, machine learning models are often preferred over their statistical counterparts for…

Methodology · Statistics 2021-04-02 Arindam Fadikar , Stefan M. Wild , Jonas Chaves-Montero

Photometric redshifts are necessary for enabling large-scale multicolour galaxy surveys to interpret their data and constrain cosmological parameters. While the increased depth of future surveys such as the Large Synoptic Survey Telescope…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-03 Daniel M. Jones , Alan F. Heavens

Accurate redshift measurements are essential for studying the evolution of quasi-stellar objects (QSOs) and their role in cosmic structure formation. While spectroscopic redshifts provide high precision, they are impractical for the vast…

Astrophysics of Galaxies · Physics 2025-07-08 Jeremy P. Moss , Stephen J. Curran , Yvette C. Perrott

Cosmography is used in cosmological data processing in order to constrain the kinematics of the universe in a model-independent way. In this paper, we first investigate the effect of the ultraviolet (UV) and X-ray relation of a quasar on…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-11 J. P. Hu , F. Y. Wang

We test the effectiveness of photometric redshifts based upon galaxy spectral template fitting for X-ray luminous objects, using a sample of 65 sources detected by Chandra in the field of the Caltech Faint Galaxy Redshift Survey (CFGRS). We…

Astrophysics · Physics 2009-11-07 Anthony H. Gonzalez , Thomas J. Maccarone

Discovering associations is of central importance in scientific practices. Currently, most researches consider only linear association measured by correlation coefficient, which has its theoretical limitations. In this paper, we propose a…

Machine Learning · Computer Science 2020-04-15 Jian Ma

Most methods for estimating configurational entropy from molecular simulation data yield upper limits except for harmonic systems where they are exact. Problems arise at diffusive systems and the presence of conformational transitions.…

Chemical Physics · Physics 2019-10-22 Jürgen Schlitter , Matthias Massarczyk

We propose a new method to estimate the photometric redshift of galaxies by using the full galaxy image in each measured band. This method draws from the latest techniques and advances in machine learning, in particular Deep Neural…

Instrumentation and Methods for Astrophysics · Physics 2016-06-16 Ben Hoyle

We use simulations to demonstrate that photometric redshift "errors" can be greatly reduced by using the photometric redshift probability distribution p(z) rather than a one-point estimate such as the most likely redshift. In principle this…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-03 D. Wittman

We describe a new program for determining photometric redshifts, dubbed EAZY. The program is optimized for cases where spectroscopic redshifts are not available, or only available for a biased subset of the galaxies. The code combines…

Astrophysics · Physics 2009-11-13 Gabriel B. Brammer , Pieter G. van Dokkum , Paolo Coppi

Three-dimensional wide-field galaxy surveys are fundamental for cosmological studies. For higher redshifts (z > 1.0), where galaxies are too faint, quasars still trace the large-scale structure of the Universe. Since available telescope…

Instrumentation and Methods for Astrophysics · Physics 2022-09-21 Sándor Kunsági-Máté , Róbert Beck , István Szapudi , István Csabai

Traditional photometric redshift methods use only color information about the objects in question to estimate their redshifts. This paper introduces a new method utilizing colors, luminosity, surface brightness, and radial light profile to…

Astrophysics · Physics 2008-11-26 James J. Wray , James E. Gunn

The cross entropy (CE) method is a model based search method to solve optimization problems where the objective function has minimal structure. The Monte-Carlo version of the CE method employs the naive sample averaging technique which is…

Artificial Intelligence · Computer Science 2018-02-01 Ajin George Joseph , Shalabh Bhatnagar