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We apply clustering-based redshift inference to all extended sources from the Sloan Digital Sky Survey photometric catalogue, down to magnitude r = 22. We map the relationships between colours and redshift, without assumption of the…

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 present the result of the Infrared Medium-deep Survey (IMS) $z\sim6$ quasar survey, using the combination of the IMS near-infrared images and the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) optical images. The traditional…

Context. Clusters of galaxies are important for cosmology and astrophysics. They may be discovered through either the summed optical/IR radiation originating from their member galaxies or via X-ray emission originating from the hot…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Alexey Mints , Axel Schwope , Simon Rosen , François-Xavier Pineau , Francisco Carrera

Recently, two classes of quasar samples were identified, which are promising as new cosmological probes extending to higher redshifts. The first sample uses the nonlinear relation between the ultraviolet and X-ray luminosities of quasars to…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-15 Xiaogang Zheng , Shuo Cao , Marek Biesiada , Xiaolei Li , Tonghua Liu , Yuting Liu

The South Galactic Cap $u$-band Sky Survey (SCUSS) provides a deep $u$-band imaging of about 5000 deg$^2$ in south Galactic cap. It is about 1.5 mag deeper than the SDSS $u$-band. In this paper we evaluate the capability of quasar selection…

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

We use a simple parameterization of the mid-IR spectra of a wide range of galaxy types in order to predict their distribution in the Infrared Array Camera (IRAC) 3.6um, 4.5um, 5.8um, and 8.0um and Multiband Photometer for Spitzer (MIPS)…

Astrophysics · Physics 2009-11-10 A. Sajina , M. Lacy , D. Scott

When analyzing galaxy clustering in multi-band imaging surveys, there is a trade-off between selecting the largest galaxy samples (to minimize the shot noise) and selecting samples with the best photometric redshift (photo-z) precision,…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-07 Dimitrios Tanoglidis , Chihway Chang , Joshua Frieman

We apply a combination of a Genetic Algorithms (GA) and Support Vector Machines (SVM) machine learning algorithm to solve two important problems faced by the astronomical community: star/galaxy separation, and photometric redshift…

Instrumentation and Methods for Astrophysics · Physics 2016-04-27 S. Heinis , S. Kumar , S. Gezari , W. S. Burgett , K. C. Chambers , P. W. Draper , H. Flewelling , N. Kaiser , E. A. Magnier , N. Metcalfe , C. Waters

We introduce a probabilistic approach to select 6<z<8 quasar candidates for spectroscopic follow-up, which is based on density estimation in the high-dimensional space inhabited by the optical and near-infrared photometry. Density…

Astrophysics of Galaxies · Physics 2022-08-03 Riccardo Nanni , Joseph F. Hennawi , Feige Wang , Jinyi Yang , Jan-Torge Schindler , Xiaohui Fan

Identifying galaxy groups from redshift surveys of galaxies plays an important role in connecting galaxies with the underlying dark matter distribution. Current and future high-$z$ spectroscopic surveys, usually incomplete in redshift…

Astrophysics of Galaxies · Physics 2020-10-14 Kai Wang , H. J. Mo , Cheng Li , Jiacheng Meng , Yangyao Chen

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 order to test the unified scheme for luminous radio galaxies and quasars we observed 10 galaxy/quasar pairs from the 3CR catalogue with ISOPHOT at infrared wavelengths between 5 and 180 micron. Each pair was selected such that both the…

Astrophysics · Physics 2009-11-06 K. Meisenheimer , M. Haas , S. A. H. Müller , R. Chini , U. Klaas , D. Lemke

ColorCheckers are reference standards that professional photographers and filmmakers use to ensure predictable results under every lighting condition. The objective of this work is to propose a new fast and robust method for automatic…

Computer Vision and Pattern Recognition · Computer Science 2018-11-29 Pedro D. Marrero Fernandez , Fidel A. Guerrero-Peña , Tsang Ing Ren , Jorge J. G. Leandro

The Complete Calibration of the Color-Redshift Relation (C3R2) survey is a multi-institution, multi-instrument survey that aims to map the empirical relation of galaxy color to redshift to i~24.5 (AB), thereby providing a firm foundation…

The K20 survey is a near infrared-selected, deep (Ks < 20) redshift survey targeting galaxies in two independent regions of the sky, the CDFS and the q0055-2659 field. The total Ks-selected sample includes 545 objects. Optical spectra for…

At high redshift, due to both observational limitations and the variety of galaxy morphologies in the early universe, measuring galaxy structure can be challenging. Non-parametric measurements such as the CAS system have thus become an…

Astrophysics of Galaxies · Physics 2021-09-08 C. Tohill , L. Ferreira , C. J. Conselice , S. P. Bamford , F. Ferrari

The second Red-sequence Cluster Survey (RCS-2) is a ~1000 square degree, multi-color imaging survey using the square-degree imager, MegaCam, on the Canada-France-Hawaii Telescope (CFHT). It is designed to detect clusters of galaxies over…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 David G. Gilbank , M. D. Gladders , H. K. C. Yee , B. C. Hsieh
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