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Edge-on galaxies have many important applications in galactic astrophysics, but they can be difficult to identify in vast amounts of astronomical data. To facilitate the search for them, we have developed a deep learning algorithm designed…

Astrophysics of Galaxies · Physics 2025-04-04 Z. Chrobakova , V. Kresnakova , R. Nagy , J. Gazdova , P. Butka

There are several supervised machine learning methods used for the application of automated morphological classification of galaxies; however, there has not yet been a clear comparison of these different methods using imaging data, or a…

Quantifying image distortions caused by strong gravitational lensing and estimating the corresponding matter distribution in lensing galaxies has been primarily performed by maximum likelihood modeling of observations. This is typically a…

Instrumentation and Methods for Astrophysics · Physics 2017-09-20 Yashar D. Hezaveh , Laurence Perreault Levasseur , Philip J. Marshall

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…

Astrophysics · Physics 2007-05-23 A. Naim

We present a study on galaxy detection and shape classification using topometric clustering algorithms. We first use the DBSCAN algorithm to extract, from CCD frames, groups of adjacent pixels with significant fluxes and we then apply the…

Instrumentation and Methods for Astrophysics · Physics 2016-10-12 A. Tramacere , D. Paraficz , P. Dubath , J. -P. Kneib , F. Courbin

Accurate measurement of galaxy structures is a prerequisite for quantitative investigation of galaxy properties or evolution. Yet, the impact of galaxy inclination and dust on commonly used metrics of galaxy structure is poorly quantified.…

Astrophysics of Galaxies · Physics 2017-03-23 Brian Devour , Eric Bell

The accuracy and robustness of a simple method to estimate the total mass profile of a galaxy is tested using a sample of 65 cosmological zoom-simulations of individual galaxies. The method only requires information on the optical surface…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 N. Lyskova , E. Churazov , I. Zhuravleva , T. Naab , L. Oser , O. Gerhard , X. Wu

We use automated surface photometry and pattern classification techniques to morphologically classify galaxies. The two-dimensional light distribution of a galaxy is reconstructed using Fourier series fits to azimuthal profiles computed in…

Astrophysics · Physics 2009-11-07 S. C. Odewahn , S. H. Cohen , R. A. Windhorst , N. S. Philip

We present the first results of our application of photometric redshifts to the study of galaxy populations in high-redshift clusters. For this survey, we are examining a sample of galaxy clusters at z > 0.6 which have already been…

Astrophysics · Physics 2007-05-23 L. M. Lubin , R. J. Brunner

Autonomous digital sky surveys such as Pan-STARRS have the ability to image a very large number of galactic and extra-galactic objects, and the large and complex nature of the image data reinforces the use of automation. Here we describe…

Astrophysics of Galaxies · Physics 2020-12-16 Hunter Goddard , Lior Shamir

In this study we present a new experimental design using clustering-based redshift inference to measure the evolving galaxy luminosity function (GLF) spanning 5.5 decades from $L \sim 10^{11.5}$ to $ 10^6 ~ \mathrm{L}_\odot$. We use data…

Weak gravitational lensing is a very sensitive way of measuring cosmological parameters, including dark energy, and of testing current theories of gravitation. In practice, this requires exquisite measurement of the shapes of billions of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 G. Nurbaeva , F. Courbin , M. Gentile , G. Meylan

It is developed a very complex system (hardware/software) to detect luminosity variations connected with the discovery of new planets outside the Solar System. Traditional imaging approaches are very demanding in terms of computing time;…

Computer Vision and Pattern Recognition · Computer Science 2007-05-23 G. Iovane

We present an application of Mathematical Morphology (MM) for the classification of astronomical objects, both for star/galaxy differentiation and galaxy morphology classification. We demonstrate that, for CCD images, 99.3 +/- 3.8 % of…

Astrophysics · Physics 2010-11-11 Jason A. Moore , Kevin A. Pimbblet , Michael J. Drinkwater

We describe a method for constructing mock galaxy catalogues which are well suited for use in conjunction with large photometric surveys. We use the semi-analytic galaxy formation model of Bower et al. implemented in the Millennium…

Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the…

Astrophysics of Galaxies · Physics 2016-10-19 Allison Merritt , Pieter van Dokkum , Roberto Abraham , Jielai Zhang

In order to prepare for the upcoming wide-field cosmological surveys, large simulations of the Universe with realistic galaxy populations are required. In particular, the tendency of galaxies to naturally align towards overdensities, an…

Accurate distances to stars and galaxies allow for significant tests of stellar evolution, galaxy formation and evolution and cosmology. NASA's Space Interferometry Mission (SIM) will obtain precision [1-30 microarcsec] astrometry for…

Astrophysics · Physics 2007-05-23 R. P. Olling , D. M. Peterson

The number density of galaxy clusters across mass and redshift has been established as a powerful cosmological probe. Cosmological analyses with galaxy clusters traditionally employ scaling relations. However, many challenges arise from…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-08 M. Kosiba , N. Cerardi , M. Pierre , F. Lanusse , C. Garrel , N. Werner , M. Shalak

This paper describes the characterization of the GALANTE photometric system, a seven intermediate- and narrow-band filter system with a wavelength coverage from 3000 $\r{A}$ to 9000 $\r{A}$ . We describe the photometric system presenting…