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Related papers: Separating the blue cloud and the red sequence usi…

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We reproduce the blue and red sequences in the observed joint distribution of colour and magnitude for galaxies at low and high redshifts using hybrid N-body/semi-analytic simulations of galaxy formation. The match of model and data is…

Astrophysics · Physics 2010-04-06 A. Cattaneo , A. Dekel , J. Devriendt , B. Guiderdoni , J. Blaizot

This is the fifth paper in a series studying the stellar components, star formation histories, star formation rates and metallicities of a blue compact galaxy (BCG) sample. Based on our high-quality ground-based spectroscopic observations,…

Astrophysics · Physics 2009-11-13 F. Shi , X. Kong , C. Li , F. Z. Cheng

Through matches with the Sloan Digital Sky Survey (SDSS) catalogue we identify the location of various families of astronomical objects in WISE colour space. We identify reliable indicators that separate Galactic/local from extragalactic…

Astrophysics of Galaxies · Physics 2014-07-03 Robert Nikutta , Nicholas Hunt-Walker , Maia Nenkova , Zeljko Ivezic , Moshe Elitzur

We model, via Monte Carlo simulations, the distribution of observed U-B, B-V, V-I galaxy colors in the range 1.75<z<5 caused by variations in the line-of-sight opacity due to neutral hydrogen (HI). We also include HI internal to the source…

Astrophysics · Physics 2009-10-31 Matthew A. Bershady , Jane C. Charlton , Janet M. Geoffroy

High-redshift clusters of galaxies are amongst the largest cosmic structures. Their properties and evolution are key ingredients to our understanding of cosmology: to study the growth of structure from the inhomogeneities of the cosmic…

Astrophysics · Physics 2007-05-23 A. Fernandez-Soto , J. Bland-Hawthorn , J. I. Gonzalez-Serrano , R. Carballo

We analyze the clustering of red and blue galaxies from four samples spanning a redshift range of 0.4<z<2.0 to test the various scenarios by which galaxies evolve onto the red sequence. The data are taken from the UKIDSS Ultra Deep Survey,…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Jeremy L. Tinker , Andrew R. Wetzel

We use the two-point correlation function in redshift space, $\xi(s)$, to study the clustering of the galaxies and groups of the Nearby Optical Galaxy (NOG) sample, which is a nearly all-sky, complete, magnitude-limited sample of $\sim$7000…

The detection of red blood cells based on morphology and colorimetric appearance is very important in improving hematology diagnostics. There are automatons capable of detecting certain forms, but these have limitations with regard to the…

Signal Processing · Electrical Eng. & Systems 2023-02-17 Jerome Nango , J. C. Alico , Sié Ouattara , Alain Clément

We study the integral Galactic extinction and reddening based on the galaxy catalog of the South Galactic Cap U-band Sky Survey (SCUSS), where $u$ band galaxy number counts and $u-r$ color distribution are used to derive the Galactic…

Given two sets $R$ and $B$ of $n$ points in the plane, we present efficient algorithms to find a two-line linear classifier that best separates the "red" points in $R$ from the "blue" points in $B$ and is robust to outliers. More precisely,…

Computational Geometry · Computer Science 2024-10-04 Erwin Glazenburg , Thijs van der Horst , Tom Peters , Bettina Speckmann , Frank Staals

Different empirical models have been developed for cloud detection. There is a growing interest in using the ground-based sky/cloud images for this purpose. Several methods exist that perform binary segmentation of clouds. In this paper, we…

Computer Vision and Pattern Recognition · Computer Science 2019-03-18 Soumyabrata Dev , Shilpa Manandhar , Yee Hui Lee , Stefan Winkler

We present a new technique to estimate the level of contamination between photometric redshift bins. If the true angular cross-correlation between redshift bins can be safely assumed to be zero, any measured cross-correlation is a result of…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-11 Jonathan Benjamin , Ludovic Van Waerbeke , Brice Ménard , Martin Kilbinger

Artificial Intelligence for RObust Glaucoma Screening (AIROGS) Challenge is held for developing solutions for glaucoma screening from color fundus photography that are robust to real-world scenarios. This report describes our method…

Computer Vision and Pattern Recognition · Computer Science 2022-02-25 Satoshi Kondo , Satoshi Kasai , Kosuke Hirasawa

We have explored the redshift evolution of the luminosity function of red and blue galaxies up to $z=3.5$. This was possible joining a deep I band composite galaxy sample, which includes the spectroscopic K20 sample and the HDFs samples,…

[Abridged] Though the exact role of infrared dark clouds in the formation process is still somewhat unclear, they seem to provide useful laboratories to study the very early stages of clustered star formation. Infrared dark clouds have been…

Astrophysics of Galaxies · Physics 2015-05-19 Wilfred W. F. Frieswijk , Russell F. Shipman

In any computer vision task involving color images, a necessary step is classifying pixels according to color and segmenting the respective areas. However, the development of methods able to successfully complete this task has proven…

Computer Vision and Pattern Recognition · Computer Science 2022-11-17 Laura Nicolás-Sáenz , Agapito Ledezma , Javier Pascau , Arrate Muñoz-Barrutia

We investigate star-galaxy classification for astronomical surveys in the context of four methods enabling the interpretation of black-box machine learning systems. The first is outputting and exploring the decision boundaries as given by…

Instrumentation and Methods for Astrophysics · Physics 2018-09-26 Xan Morice-Atkinson , Ben Hoyle , David Bacon

We use the two-point correlation function in redshift space, $\xi(s)$, to study the clustering of the galaxies and groups of the Nearby Optical Galaxy (NOG) Sample, which is a nearly all-sky, complete, magnitude-limited sample of \~7000…

Astrophysics · Physics 2007-05-23 G. Giuricin , S. Samurovic , M. Girardi , M. Mezzetti , C. Marinoni

Image segmentation is to separate an image into distinct homogeneous regions belonging to different objects. It is an essential step in image analysis and computer vision. This paper compares some segmentation technologies and attempts to…

Computer Vision and Pattern Recognition · Computer Science 2008-03-18 Li Chen

We measure the intrinsic alignments of the blue and the red galaxies separately by analyzing the spectroscopic data of the Sloan Digital Sky Survey Data Release 6 (SDSS DR6). For both samples of the red and the blue galaxies with axial…

Astrophysics · Physics 2009-11-13 Jounghun Lee , Ue-Li Pen