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

The global colors of galaxies have recently been shown to follow bimodal distributions. Galaxies separate into a ``red sequence'', populated prototypically by early-type galaxies, and a ``blue cloud'', whose typical objects are late-type…

We present new quantitative classification methods for emission-line galaxies, which are specially designed to be used in deep galaxy redshift surveys. A good segregation between starbursts and active galactic nuclei, i.e. Seyferts 2s and…

We propose a new method to investigate the coefficient of the selective extinction, based on two band photometry. This method uses red clump stars as a means to construct the reddening curve. We apply this method to the OGLE color-magnitude…

In this study, we propose a three-stage training approach of neural networks for both photometric redshift estimation of galaxies and detection of out-of-distribution (OOD) objects. Our approach comprises supervised and unsupervised…

We describe an automated method, the Cut & Enhance method (CE) for detecting clusters of galaxies in multi-color optical imaging surveys. This method uses simple color cuts, combined with a density enhancement algorithm, to up-weight pairs…

Classifying catalog objects as stars, galaxies, or AGN is a crucial part of any statistical study of galaxies. We describe our pipeline for binary (star/galaxy) and multiclass (star/galaxy/Type I AGN/Type II AGN) classification developed…

We develop a galaxy cluster finding algorithm based on spectral clustering technique to identify optical counterparts and estimate optical redshifts for X-ray selected cluster candidates. As an application, we run our algorithm on a sample…

The orientations of the red galaxies in a filament are aligned with the orientation of the filament. We thus develop a location-alignment-method (LAM) of detecting filaments around clusters of galaxies, which uses both the alignments of red…

In this paper we present a novel method to identify and characterize stellar clusters deeply embedded in a dark molecular cloud. The method is based on measuring stellar surface density in wide-field infrared images using star counting…

In this paper we discuss the mix of star-forming and passive galaxies up to z~2, based on the first epoch VIMOS-VLT Deep Survey (VVDS) data.In agreement with previous works we find that the galaxy rest-frame color distribution follows a…

The problem of automated separation of stars and galaxies on photographic plates is revisited with two goals in mind : First, to separate galaxies from everything else (as opposed to most previous work, in which galaxies were lumped…

We use the overlap between multiband photometry of the Kilo-Degree Survey (KiDS) and spectroscopic data based on the Sloan Digital Sky Survey (SDSS) and Galaxy And Mass Assembly (GAMA) to infer the colour-magnitude relation of red-sequence…

We study the spectral classification of emission-line galaxies as star-forming galaxies or Active Galactic Nuclei (AGNs). From the Sloan Digital Sky Survey (SDSS) high quality data, we define an improved classification to be used for high…

We present measurements of the angular correlation function of galaxies selected from a B_J=23.5 multicolour survey of two 5 degree by 5 degree fields located at high galactic latitudes. The galaxy catalogue of approximately 400,000…

We investigate the potential and accuracy of clustering-based redshift estimation using the method proposed by M\'enard et al. (2013). This technique enables the inference of redshift distributions from measurements of the spatial…

We present measurements of the higher-order clustering of red and blue galaxies as a function of scale and luminosity made from the two-degree field galaxy redshift survey (2dFGRS). We use a counts-in-cells analysis to estimate the volume…

Image processing is an important research area in computer vision. Image segmentation plays the vital rule in image processing research. There exist so many methods for image segmentation. Clustering is an unsupervised study. Clustering can…

We present initial results from a wide-field, multi-colour imaging project, designed to study galaxy evolution in X-ray selected clusters at intermediate (z~0.25) and high redshifts (z~0.5). In this paper we give blue galaxy fractions from…

Photometric redshift classifiers provide a means of estimating galaxy redshifts from observations using a small number of broad-band filters. However, the accuracy with which redshifts can be determined is sensitive to the star formation…

We study the clustering of galaxies, as a function of their colour, from Data Release Ten (DR10) of the SDSS-III Baryon Oscillation Spectroscopic Survey. We select 122,967 galaxies with 0.43 < z < 0.7 into a "Blue" sample and 131,969 into a…