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Related papers: Photometric Redshifts with Copula Entropy

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Cross-correlations between the galaxy number density in a lensing source sample and that in an overlapping spectroscopic sample can in principle be used to calibrate the lensing source redshift distribution. In this paper, we study in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Roland de Putter , Olivier Doré , Sudeep Das

Interstellar dust contains a component which reveals its presence by emitting a broad, unstructured band of light in the 540 to 950 nm wavelength range, referred to as Extended Red Emission (ERE). The presence of interstellar dust and…

Astrophysics · Physics 2009-11-07 Tracy L. Smith , Adolf N. Witt

From SDSS commissioning photometric and spectroscopic data, we investigate the utility of photometric redshift techniques to the task of estimating QSO redshifts. We consider empirical methods (e.g. nearest-neighbor searches and polynomial…

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

Studies of the distribution and evolution of galaxies are of fundamental importance to modern cosmology; these studies, however, are hampered by the complexity of the competing effects of spectral and density evolution. Constructing a…

Astrophysics · Physics 2009-10-31 R. J. Brunner , A. J. Connolly , A. S. Szalay

Photometric redshifts are essential in studies of both galaxy evolution and cosmology, as they enable analyses of objects too numerous or faint for spectroscopy. The Rubin Observatory, Euclid, and Roman Space Telescope will soon provide a…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-28 Jeffrey A. Newman , Daniel Gruen

Previous measurements utilizing Maxwell relations to measure change in entropy, $S$, demonstrated remarkable accuracy of measuring the spin-1/2 entropy of electrons in a weakly coupled quantum dot. However, these previous measurements…

Mesoscale and Nanoscale Physics · Physics 2022-04-06 Tim Child , Owen Sheekey , Silvia Lüscher , Saeed Fallahi , Geoffrey C. Gardner , Michael Manfra , Joshua Folk

The accuracy of approximate methods for calculating linear optical spectra depends on many variables. In this study, we fix most of these parameters to typical values found in photosynthetic light-harvesting complexes of plants and…

Chemical Physics · Physics 2022-09-21 J. A. Nöthling , Tomáš Mančal , T. P. J. Krüger

We study how the addition of on-board optical photometric bands to future space-based weak lensing instruments could affect the photometric redshift estimation of galaxies, and hence improve estimations of the dark energy parameters through…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Robert Sorba , Marcin Sawicki

Context. Investigating the diagnostic power of H$\alpha$/H$\beta$ Charge-Exchange (CE) emission as Low-Energy Galactic Cosmic Rays(LECRs) tracer in diffuse regions. Aims. In this work, we define and test a spectroscopic indicator of CE…

Astrophysics of Galaxies · Physics 2024-04-04 I. Busa , S. Cabibbo , C. Trigilio , F. Leone

While the (weak) Equivalence Principle (EP) has been rigorously tested within the solar system, its validity on cosmological scales, particularly in the context of dark matter and dark energy, remains uncertain. In this study, we propose a…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-06 Guoyuan Lu , Yi Zheng , Le Zhang , Xiaodong Li , Jiacheng Ding , Kwan Chuen Chan

The use of type Ia supernovae (SNe Ia) as cosmological standard candles is fundamental in modern observational cosmology. In this letter, we derive a simple empirical photometric redshift estimator for SNe Ia using a training set of SNe Ia…

Astrophysics · Physics 2010-11-05 Yun Wang

We present the first results of our application of photometric redshifts to the study of galaxy populations in high-redshift clusters. For this survey, we are examining a sample of galaxy clusters at z > 0.6 which have already been…

Astrophysics · Physics 2007-05-23 L. M. Lubin , R. J. Brunner

Loss functions play a crucial role in deep metric learning thus a variety of them have been proposed. Some supervise the learning process by pairwise or tripletwise similarity constraints while others take advantage of structured similarity…

Machine Learning · Computer Science 2019-11-25 Xinshao Wang , Elyor Kodirov , Yang Hua , Neil Robertson

Spectroscopic redshift errors, including redshift uncertainty and catastrophic failures, can bias cosmological measurements from galaxy redshift surveys at sub-percent level. In this work, we investigate their impact on the full-shape…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-17 Shengyu He , Jiaxi Yu , Antoine Rocher , Daniel Forero-Sánchez , Jean-Paul Kneib , Cheng Zhao , Etienne Burtin , Jiamin Hou

A variety of on-orbit imaging and spectroscopic observations are used to characterize the Charge Transfer Efficiency (CTE) of the Charge-Coupled Device (CCD) of the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space…

Astrophysics · Physics 2009-11-11 Paul Goudfrooij , Ralph C. Bohlin , Jesus Maiz-Apellaniz , Randy A. Kimble

The current role of data-driven science is constantly increasing its importance within Astrophysics, due to the huge amount of multi-wavelength data collected every day, characterized by complex and high-volume information requiring…

Instrumentation and Methods for Astrophysics · Physics 2021-04-15 Massimo Brescia , Stefano Cavuoti , Oleksandra Razim , Valeria Amaro , Giuseppe Riccio , Giuseppe Longo

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