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Related papers: Photometric Redshifts and Photometry Errors

200 papers

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

Many astrophysical analyses depend on estimates of redshifts (a proxy for distance) determined from photometric (i.e., imaging) data alone. Inaccurate estimates of photometric redshift uncertainties can result in large systematic errors.…

Instrumentation and Methods for Astrophysics · Physics 2022-05-31 Biprateep Dey , Jeffrey A. Newman , Brett H. Andrews , Rafael Izbicki , Ann B. Lee , David Zhao , Markus Michael Rau , Alex I. Malz

In the next years, several cosmological surveys will rely on imaging data to estimate the redshift of galaxies, using traditional filter systems with 4-5 optical broad bands; narrower filters improve the spectral resolution, but strongly…

We analyze the impact of photon loss on the photon-number statistics of Gaussian states. Specifically, we propose and carefully evaluate several methods to mitigate deviations in the photon-number distributions of lossy (displaced) squeezed…

Quantum Physics · Physics 2026-03-24 Hendrik Ellenberg , René Sondenheimer

Based on the SDSS and SDSS-WISE quasar datasets, we put forward two schemes to estimate the photometric redshifts of quasars. Our schemes are based on the idea that the samples are firstly classified into subsamples by a classifier and then…

Instrumentation and Methods for Astrophysics · Physics 2019-12-05 Yanxia Zhang , Jingyi Zhang , Xin Jin , Yongheng Zhao

I describe a Bayesian method to account for measurement errors in linear regression of astronomical data. The method allows for heteroscedastic and possibly correlated measurement errors, and intrinsic scatter in the regression…

Astrophysics · Physics 2009-06-23 Brandon C. Kelly

This white paper summarizes the conclusions of the Snowmass White Paper "Spectroscopic Needs for Imaging Dark Energy Experiments" (arXiv:1309.5384) which are relevant to the calibration of LSST photometric redshifts; i.e., the accurate…

Instrumentation and Methods for Astrophysics · Physics 2014-10-17 Samuel J. Schmidt , Jeffrey A. Newman , Alexandra Abate , the Spectroscopic Needs White Paper Team

Photometric redshift estimation is an indispensable tool of precision cosmology. One problem that plagues the use of this tool in the era of large-scale sky surveys is that the bright galaxies that are selected for spectroscopic observation…

Instrumentation and Methods for Astrophysics · Physics 2017-07-18 Peter E. Freeman , Rafael Izbicki , Ann B. Lee

Redshifts have been so easy to measure for so long that we tend to neglect the fact that they too have uncertainties and are susceptible to systematic error. As we strive to measure cosmological parameters to better than 1% it is worth…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-02 Tamara M. Davis , Samuel R. Hinton , Cullan Howlett , Josh Calcino

We review the use of photometric redshifts in the particular context of Gravitational Telescopes. We discuss on the possible application of such a technique to the study of both the faint population of distant sources and the properties of…

The use of photometric redshifts in cosmology is increasing. Often, however these photo-zs are treated like spectroscopic observations, in that the peak of the photometric redshift, rather than the full probability density function (PDF),…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Adam D Myers , Martin White , Nicholas M. Ball

Until now, systematic errors in strong gravitational lens modeling have been acknowledged but never been fully quantified. Here, we launch an investigation into the systematics induced by constraint selection. We model the simulated cluster…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-21 Traci L. Johnson , Keren Sharon

We calculate photometric redshifts from the Sloan Digital Sky Survey Main Galaxy Sample, The Galaxy Evolution Explorer All Sky Survey, and The Two Micron All Sky Survey using two new training-set methods. We utilize the broad-band…

Astrophysics · Physics 2008-11-26 M. J. Way , A. N. Srivastava

This work analyzes the RAID dataset to evaluate human responses to affine image distortions, including rotation, translation, scaling, and Gaussian noise. Using Mean Squared Error (MSE), the study establishes human detection thresholds for…

Context: Understanding the source of systematic errors in photometry is essential for their calibration. Aims: We investigate how photometry performed on difference images can be influenced by errors in the photometric scale factor.…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 D. M. Bramich , E. Bachelet , K. A. Alsubai , D. Mislis , N. Parley

We present a new machine learning model for estimating photometric redshifts with improved accuracy for galaxies in Pan-STARRS1 data release 1. Depending on the estimation range of redshifts, this model based on neural networks can handle…

Instrumentation and Methods for Astrophysics · Physics 2021-12-09 Joongoo Lee , Min-Su Shin

We investigate the impact of photometric signal-to-noise (S/N) on the precision of photometric redshifts in multi-band imaging surveys, using both simulations and real data. We simulate the optical 4-band (BVRz) Deep Lens Survey (DLS,…

Astrophysics · Physics 2009-11-13 V. E. Margoniner , D. M. Wittman

The single-scatter approximation is fundamental in many tomographic imaging problems including x-ray scatter imaging and optical scatter imaging for certain media. In all cases, noisy measurements are affected by both local scatter events…

Image and Video Processing · Electrical Eng. & Systems 2021-04-21 Michael R. Walker , Joseph A. O'Sullivan

We compare the latest results from CMB experiments at scales around $l_e \sim 150$ over different parts of the sky to test the hypothesis that they are drawn from a Gaussian distribution, as is usually assumed. Using both the diagonal and…

Astrophysics · Physics 2009-10-30 E. Gaztanaga , P. Fosalba , E. Elizalde

Residual errors in shear measurements, after corrections for instrument systematics and atmospheric effects, can impact cosmological parameters derived from weak lensing observations. Here we combine convergence maps from our suite of…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-06 Andrea Petri , Morgan May , Zoltan Haiman , Jan M. Kratochvil
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