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Related papers: UPMASK: unsupervised photometric membership assign…

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This review summarizes popular unsupervised learning methods, and gives an overview of their past, current, and future uses in astronomy. Unsupervised learning aims to organise the information content of a dataset, in such a way that…

Instrumentation and Methods for Astrophysics · Physics 2024-06-26 Sotiria Fotopoulou

We review progress in numerical simulations of star cluster formation. These simulations involve the bottom-up assembly of clusters through hierarchical mergers, which produces a fractal stellar distribution at young (~0.5 Myr) ages. The…

Astrophysics of Galaxies · Physics 2015-05-14 Cathie Clarke

We have used Washington photometry for 90 star cluster candidates of small angular size -typically ~ 11" in radius- distributed within nine selected regions in the inner disc of the Large Magellanic Cloud (LMC) to disentangle whether they…

Astrophysics of Galaxies · Physics 2015-06-19 Andres E. Piatti

The integrated spectro-photometric properties of star clusters are subject to large cluster-to-cluster variations. They are distributed in non trivial ways around the average properties predicted by standard population synthesis models.…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-20 M. Fouesneau , A. Lançon

We present an approach that improves the search for reliable astrophysical parameters (e.g. age, mass, and distance) of differentially-reddened, pre-main sequence-rich star clusters. It involves simulating conditions related to the…

Astrophysics of Galaxies · Physics 2015-06-03 Charles Bonatto , Eduardo Bica , Eliade F. Lima

We study the capability of the UBVRI photometric system to quantify star clusters in terms of age, metallicity, and color excess by their integrated photometry. The well known age-metallicity-extinction degeneracy was analyzed for various…

Astrophysics · Physics 2008-11-26 D. Narbutis , A. Bridzius , R. Stonkute , V. Vansevicius

We present a study of 7 southern open clusters based on UBVRI CCD photomety (Johnsons-Cousins system) and Gaia DR2 data. Dias 4, Dias 6 and four other clusters had UBVRI photometric observations determined for the first time. From the…

Solar and Stellar Astrophysics · Physics 2018-09-05 Wilton S. Dias , Hektor Monteiro , Jacques R. D. Lépine , R. Prates , C. D. Gneiding , M. Sacchi

A limitation of many clustering algorithms is the requirement to tune adjustable parameters for each application or even for each dataset. Some techniques require an \emph{a priori} estimate of the number of clusters while density-based…

Methodology · Statistics 2016-05-20 Jeremy F. Magland , Alex H. Barnett

Accurate land cover segmentation of spectral images is challenging and has drawn widespread attention in remote sensing due to its inherent complexity. Although significant efforts have been made for developing a variety of methods, most of…

Image and Video Processing · Electrical Eng. & Systems 2021-11-30 Carlos Hinojosa , Esteban Vera , Henry Arguello

High resolution spectral models for simple stellar populations (SSP) developed in the past few years have become a standard ingredient in studies of stellar population of galaxies. As more such models become available, it becomes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Roberto Cid Fernandes , Rosa M. Gonzalez Delgado

Point cloud upsampling aims to generate dense and uniformly distributed point sets from sparse point clouds. Existing point cloud upsampling methods typically approach the task as an interpolation problem. They achieve upsampling by…

Image and Video Processing · Electrical Eng. & Systems 2025-02-28 Ziming Nie , Qiao Wu , Chenlei Lv , Siwen Quan , Zhaoshuai Qi , Muze Wang , Jiaqi Yang

Subspace clustering, the task of clustering high dimensional data when the data points come from a union of subspaces is one of the fundamental tasks in unsupervised machine learning. Most of the existing algorithms for this task require…

Machine Learning · Statistics 2020-10-28 Vishnu Menon , Gokularam M , Sheetal Kalyani

We measure the velocity dispersions of six, galactic globular clusters using spatially integrated spectra, to test for the effects of internal dynamical evolution in the stellar mass-to-light ratios, Upsilon_*, of star clusters. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Dennis Zaritsky , Janet E. Colucci , Peter M. Pessev , Rebecca A. Bernstein , Rupali Chandar

The physical properties of star cluster populations offer valuable insights into their birth, evolution, and disruption. However, individual stars in clusters beyond the nearest neighbours of the Milky Way are unresolved, forcing analyses…

Astrophysics of Galaxies · Physics 2024-07-24 Jianling Tang , Kathryn Grasha , Mark R. Krumholz

The last few years have seen the emergence of a wide array of novel techniques for analyzing high-precision data from upcoming galaxy surveys, which aim to extend the statistical analysis of galaxy clustering data beyond the linear regime…

Hyperspectral image unmixing is an inverse problem aiming at recovering the spectral signatures of pure materials of interest (called endmembers) and estimating their proportions (called abundances) in every pixel of the image. However, in…

Image and Video Processing · Electrical Eng. & Systems 2019-11-28 Lucas Drumetz , Mauro Dalla Mura , Guillaume Tochon , Ronan Fablet

Variations in the photometric parameters of stellar systems as a function of their evolution and the stellar populations comprising them are investigated. A set of seven evolutionary models with an exponential decrease in the star-formation…

We investigate the stellar populations of galaxies in clusters at different dynamical stages, aiming to identify possible effects of the relaxation state of the cluster or subcluster on the star formation histories of its galaxies. We have…

Astrophysics of Galaxies · Physics 2018-12-19 N. R. Soares , S. B. Rembold

During the last ten years, a considerable amount of effort has been made to develop algorithms for automatic classification of variable stars. That has been primarily achieved by applying machine learning methods to photometric datasets…

Instrumentation and Methods for Astrophysics · Physics 2018-01-31 Lucas Valenzuela , Karim Pichara

In this work, we update the unsupervised machine learning (UML) step by proposing an algorithm based on ConvNeXt large model coding to improve the efficiency of unlabeled galaxy morphology classifications. The method can be summarized into…

Astrophysics of Galaxies · Physics 2025-01-03 Guanwen Fang , Yao Dai , Zesen Lin , Chichun Zhou , Jie Song , Yizhou Gu , Xiaotong Guo , Anqi Mao , Xu Kong
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