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Photometric redshift estimation algorithms are often based on representative data from observational campaigns. Data-driven methods of this type are subject to a number of potential deficiencies, such as sample bias and incompleteness.…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 Nesar Ramachandra , Jonás Chaves-Montero , Alex Alarcon , Arindam Fadikar , Salman Habib , Katrin Heitmann

We use numerical simulations to characterize the performance of a clustering-based method to calibrate photometric redshift biases. In particular, we cross-correlate the weak lensing (WL) source galaxies from the Dark Energy Survey Year 1…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 M. Gatti , P. Vielzeuf , C. Davis , R. Cawthon , M. M. Rau , J. DeRose , J. De Vicente , A. Alarcon , E. Rozo , E. Gaztanaga , B. Hoyle , R. Miquel , G. M. Bernstein , C. Bonnett , A. Carnero Rosell , F. J. Castander , C. Chang , L. N. da Costa , D. Gruen , J. Gschwend , W. G. Hartley , H. Lin , N. MacCrann , M. A. G. Maia , R. L. C. Ogando , A. Roodman , I. Sevilla-Noarbe , M. A. Troxel , R. H. Wechsler , J. Asorey , T. M. Davis , K. Glazebrook , S. R. Hinton , G. Lewis , C. Lidman , E. Macaulay , A. Möller , C. R. O'Neill , N. E. Sommer , S. A. Uddin , F. Yuan , B. Zhang , T. M. C. Abbott , S. Allam , J. Annis , K. Bechtol , D. Brooks , D. L. Burke , D. Carollo , M. Carrasco Kind , J. Carretero , C. E. Cunha , C. B. D'Andrea , D. L. DePoy , S. Desai , T. F. Eifler , A. E. Evrard , B. Flaugher , P. Fosalba , J. Frieman , J. García-Bellido , D. W. Gerdes , D. A. Goldstein , R. A. Gruendl , G. Gutierrez , K. Honscheid , J. K. Hoormann , B. Jain , D. J. James , M. Jarvis , T. Jeltema , M. W. G. Johnson , M. D. Johnson , E. Krause , K. Kuehn , S. Kuhlmann , N. Kuropatkin , T. S. Li , M. Lima , J. L. Marshall , P. Melchior , F. Menanteau , R. C. Nichol , B. Nord , A. A. Plazas , K. Reil , E. S. Rykoff , M. Sako , E. Sanchez , V. Scarpine , M. Schubnell , E. Sheldon , M. Smith , R. C. Smith , M. Soares-Santos , F. Sobreira , E. Suchyta , M. E. C. Swanson , G. Tarle , D. Thomas , B. E. Tucker , D. L. Tucker , V. Vikram , A. R. Walker , J. Weller , W. Wester , R. C. Wolf

We use the deepest and most complete redshift catalog currently available (the Hubble Deep Field (HDF) North supplemented by new HDF South redshift data) to minimize residuals between photometric and spectroscopic redshift estimates. The…

Astrophysics · Physics 2016-08-30 M. Massarotti , A. Iovino , A. Buzzoni , D. Valls--Gabaud

We present photometric redshifts for 1 341 559 galaxies from the Physics of the Accelerating Universe Survey (PAUS) over 50.38 ${\rm deg}^{2}$ of sky to $i_{\rm AB}=23$. Redshift estimation is performed using DEEPz, a deep-learning…

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

We present a new training set for estimating empirical photometric redshifts of galaxies, which was created as part of the 2dFLenS project. This training set is located in a 700 sq deg area of the KiDS South field and is randomly selected…

We apply Bayesian statistics with prior probabilities of galaxy surface luminosity (SL) to improve photometric redshifts. We apply the method to a sample of 1266 galaxies with spectroscopic redshifts in the GOODS North and South fields at…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Lifang Xia , Seth Cohen , Sangeeta Malhotra , James Rhoads , Norman Grogin , Nimish P. Hathi , Rogier A. Windhorst , Nor Pirzkal , Chun Xu

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

We present a new approach to the problem of estimating the redshift of galaxies from photometric data. The approach uses a genetic algorithm combined with non-linear regression to model the 2SLAQ LRG data set with SDSS DR7 photometry. The…

Instrumentation and Methods for Astrophysics · Physics 2015-04-14 Robert Hogan , Malcolm Fairbairn , Navin Seeburn

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

Accurate photometric redshifts are among the key requirements for precision weak lensing measurements. Both the large size of the Sloan Digital Sky Survey (SDSS) and the existence of large spectroscopic redshift samples that are…

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

Photometric redshifts are estimated on the basis of template scenarios with the help of the code ZPEG, an extension of the galaxy evolution model PEGASE.2 and available on the PEGASE web site. The spectral energy distribution (SED)…

Astrophysics · Physics 2009-11-07 Damien Le Borgne , Brigitte Rocca-Volmerange

Many scientific investigations of photometric galaxy surveys require redshift estimates, whose uncertainty properties are best encapsulated by photometric redshift (photo-z) posterior probability density functions (PDFs). A plethora of…

We conduct a comprehensive study of the effects of incorporating galaxy morphology information in photometric redshift estimation. Using machine learning methods, we assess the changes in the scatter and catastrophic outlier fraction of…

The success of future large scale weak lensing surveys will critically depend on the accurate estimation of photometric redshifts of very large samples of galaxies. This in turn depends on both the quality of the photometric data and the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 R. Bordoloi , S. J. Lilly , A. Amara , P. A. Oesch , S. Bardelli , E. Zucca , D. Vergani , T. Nagao , T. Murayama , Y. Shioya , Y. Taniguchi

We present a study of photometric redshift accuracy in the 3D-HST photometric catalogs, using 3D-HST grism redshifts to quantify and dissect trends in redshift accuracy for galaxies brighter than $H_{F140W}<24$ with an unprecedented and…

We present a new method to marginalize over uncertainties in redshift distributions, $N(z)$, within tomographic cosmological analyses applicable to current and upcoming photometric galaxy surveys. We allow for arbitrary deviations from the…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-11 Boryana Hadzhiyska , David Alonso , Andrina Nicola , Anže Slosar

We present a galaxy group-finding algorithm, the Photo-z Probability Peaks (P3) algorithm, optimized for locating small galaxy groups using photometric redshift data by searching for peaks in the signal-to-noise of the local overdensity of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Bryan Gillis , Michael J. Hudson

Photometric redshifts (photo-z) are crucial to the scientific exploitation of modern panchromatic digital surveys. In this paper we present PhotoRApToR (Photometric Research Application To Redshift): a Java/C++ based desktop application…

Instrumentation and Methods for Astrophysics · Physics 2016-10-31 Stefano Cavuoti , Massimo Brescia , Virgilio De Stefano , Giuseppe Longo