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Aims. We use the spectra of more than 30,000 red giant branch (RGB) stars in 25 globular clusters (GC), obtained within the MUSE survey of Galactic globular clusters, to calibrate the Ca II triplet (CaT) metallicity relation and derive…

We describe and summarize the findings from our CCD time-series photometry of globular clusters (GCs) program and the use of difference image analysis (DIA) in the extraction of very precise light curves even in the crowded central regions…

Solar and Stellar Astrophysics · Physics 2017-01-11 A. Arellano Ferro , D. M. Bramich , S. Giridhar

We study the geometry and topology of the large-scale structure traced by galaxy clusters in numerical simulations of a box of side 320 $h^{-1}$ Mpc, and compare them with available data on real clusters. The simulations we use are…

Astrophysics · Physics 2020-11-25 P. Coles , R. C. Pearson , S. Borgani , M. Plionis , L. Moscardini

A wide range of (multivariate) temporal (1D) and spatial (2D) data analysis tasks, such as grouping vehicle sensor trajectories, can be formulated as clustering with given metric constraints. Existing metric-constrained clustering…

Machine Learning · Computer Science 2024-06-04 Zhangyu Wang , Gengchen Mai , Krzysztof Janowicz , Ni Lao

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…

Computer Vision and Pattern Recognition · Computer Science 2014-07-31 Dibya Jyoti Bora , Anil Kumar Gupta

The cross-correlation between 21-cm intensity mapping experiments and photometric surveys of galaxies (or any other cosmological tracer with a broad radial kernel) is severely degraded by the loss of long-wavelength radial modes due to…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-19 Caroline Guandalin , Isabella P. Carucci , David Alonso , Kavilan Moodley

Convex clustering is a modern method with both hierarchical and $k$-means clustering characteristics. Although convex clustering can capture complex clustering structures hidden in data, the existing convex clustering algorithms are not…

Machine Learning · Statistics 2023-12-22 Daniel J. W. Touw , Patrick J. F. Groenen , Yoshikazu Terada

An appropriate distance metric is crucial for categorical data clustering, as the distance between categorical data cannot be directly calculated. However, the distances between attribute values usually vary in different clusters induced by…

Machine Learning · Computer Science 2026-03-09 Taixi Chen , Yiu-ming Cheung , Yiqun Zhang

We state theoretical properties for $k$-means clustering of Symmetric Positive Definite (SPD) matrices, in a non-Euclidean space, that provides a natural and favourable representation of these data. We then provide a novel application for…

Machine Learning · Statistics 2024-10-30 Daniel Fryer , Hien Nguyen , Pascal Castellazzi

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

A general method to obtain a representation of the structural landscape of nanoparticles in terms of a limited number of variables is proposed. The method is applied to a large dataset of parallel tempering molecular dynamics simulations of…

We have obtained broad-band near-infrared photometry for seven Galactic star clusters (M92, M15, M13, M5, NGC1851, M71 and NGC6791) using the WIRCam wide-field imager on the Canada-France-Hawaii Telescope, supplemented by images of NGC1851…

Solar and Stellar Astrophysics · Physics 2015-05-20 Crystal Brasseur , Peter B. Stetson , Don A. VandenBerg , Luca Casagrande , Giuseppe Bono , Massimo Dall'Ora

Complex vector light modes with a spatial variant polarization distribution have become topical of late, enabling the development of novel applications in numerous research fields. Key to this is the remarkable similarities they hold with…

Optics · Physics 2022-02-02 Xiaobo Hu , Carmelo Rosales Guzman

We present validated and forward-modelled galaxy luminosity functions and photometric predictions for the Vera C. Rubin Observatory Legacy Survey of Space and Time using the ASTRID cosmological hydrodynamical simulation. Galaxy magnitudes…

Galaxy clusters are important cosmological probes that have helped to establish the $\mathrm{\Lambda}$CDM paradigm as the standard model of cosmology. However, recent tensions between different types of high-accuracy data highlight the need…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-04 Nikolaos Triantafyllou , Giorgos Korkidis , Vasiliki Pavlidou , Paolo Bonfini

Convex clustering has recently garnered increasing interest due to its attractive theoretical and computational properties, but its merits become limited in the face of high-dimensional data. In such settings, pairwise affinity terms that…

Methodology · Statistics 2021-04-02 Saptarshi Chakraborty , Jason Xu

We present this paper in conjuction with the following as the first results in the CFHT Open Star Cluster Survey. This survey is a large BVR imaging data set of 19 open star clusters in our Galaxy. This data set was taken with the CFH12K…

Mahdavi et al. find that the degree of agreement between weak lensing and X-ray mass measurements is a function of cluster radius. Numerical simulations also point out that X-ray mass proxies do not work equally well at all radii. The…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-22 Yu-Ying Zhang , Thomas H Reiprich , Alexis Finoguenov , Daniel S. Hudson , Craig L Sarazin

The paper explores the industrial multimodal Anomaly Detection (AD) task, which exploits point clouds and RGB images to localize anomalies. We introduce a novel light and fast framework that learns to map features from one modality to the…

Computer Vision and Pattern Recognition · Computer Science 2024-07-09 Alex Costanzino , Pierluigi Zama Ramirez , Giuseppe Lisanti , Luigi Di Stefano

This paper develops a method for obtaining the star formation histories of a mixed, resolved population through the use of color-magnitude diagrams (CMDs). The method provides insight into the local star formation rate, analyzing the…

Astrophysics · Physics 2009-11-11 M. Cignoni , S. Degl'Innocenti , P. G. Prada Moroni , S. N. Shore
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