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Related papers: Unsupervised classification of SDSS galaxy spectra

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In semi-supervised learning for classification, it is assumed that every ground truth class of data is present in the small labelled dataset. Many real-world sparsely-labelled datasets are plausibly not of this type. It could easily be the…

Machine Learning · Statistics 2021-01-11 Matthew Willetts , Stephen J Roberts , Christopher C Holmes

The discovery of outsiders in the form of unusual, rare, or even unknown object types is important as they can provide useful information about otherwise hidden physical phenomena and processes. The present study takes advantage of the fact…

Astrophysics of Galaxies · Physics 2026-01-14 Helmut Meusinger

We describe the scientific motivation behind, and the methodology of, the Stanford Cluster Search (StaCS), a program to compile a catalog of optically selected clusters of galaxies at intermediate and high (0.3 < z < 1) redshifts. The…

We present CLARA, a modular framework for unsupervised transit detection in TESS light curves, leveraging Unsupervised Random Forests (URFs) trained on synthetic datasets and guided by morphological similarity analysis. This work addresses…

Instrumentation and Methods for Astrophysics · Physics 2025-09-24 Mainak Dasgupta

To further our knowledge of the complex physical process of galaxy formation, it is essential that we characterize the formation and evolution of large databases of galaxies. The spectral synthesis STARLIGHT code of Cid Fernandes et al.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Joseph W. Richards , Peter E. Freeman , Ann B. Lee , Chad M. Schafer

Aims. We intend to compile a new galaxy group and cluster sample of the latest available SDSS data, adding several parameter for the purpose of studying the supercluster network, galaxy and group evolution, and their connection to the…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-29 E. Tempel , E. Tago , L. J. Liivamägi

We present an automatic procedure to perform reliable photometry of galaxies on SDSS images. We selected a sample of 5853 galaxies in the Coma and Virgo superclusters. For each galaxy, we derive Petrosian g and i magnitudes, surface…

Astrophysics of Galaxies · Physics 2016-06-08 Guido Consolandi , Giuseppe Gavazzi , Michele Fumagalli , Massimo Dotti , Matteo Fossati

We present the catalogue of blended galaxy spectra from the Galaxy And Mass Assembly (GAMA) survey. These are cases where light from two galaxies are significantly detected in a single GAMA fibre. Galaxy pairs identified from their blended…

The Pan-STARRS1 survey is obtaining multi-epoch imaging in 5 bands (gps rps ips zps yps) over the entire sky North of declination -30deg. We describe here the implementation of the Photometric Classification Server (PCS) for Pan-STARRS1.…

Retrieving the Star Formation History (SFH) of a galaxy out of its integrated spectrum is the central goal of stellar population synthesis. Recent advances in evolutionary synthesis models have given new breath to this old field of…

Unsupervised clustering, also known as natural clustering, stands for the classification of data according to their similarities. Here we study this problem from the perspective of complex networks. Mapping the description of data…

Data Analysis, Statistics and Probability · Physics 2012-08-22 Clara Granell , Sergio Gomez , Alex Arenas

A fundamental bimodality of galaxies in the local Universe is apparent in many of the features used to describe them. Multiple sub-populations exist within this framework, each representing galaxies following distinct evolutionary pathways.…

We present a dataset built for machine learning applications consisting of galaxy photometry, images, spectroscopic redshifts, and structural properties. This dataset comprises 286,401 galaxy images and photometry from the Hyper-Suprime-Cam…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-02 Tuan Do , Bernie Boscoe , Evan Jones , Yun Qi Li , Kevin Alfaro

We present an optically-selected catalog of 1073 galaxy cluster and group candidates at 0.3<z<1. These candidates are drawn from the Las Campanas Distant Clusters Survey (LCDCS), a drift-scan imaging survey of a 130 square degree strip of…

Astrophysics · Physics 2009-11-06 Anthony H. Gonzalez , Dennis Zaritsky , Julianne J. Dalcanton , Amy Nelson

We present a new algorithm, CAMIRA, to identify clusters of galaxies in wide-field imaging survey data. We base our algorithm on the stellar population synthesis model to predict colours of red-sequence galaxies at a given redshift for an…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Masamune Oguri

Subtype Discovery consists in finding interpretable and consistent sub-parts of a dataset, which are also relevant to a certain supervised task. From a mathematical point of view, this can be defined as a clustering task driven by…

Machine Learning · Statistics 2021-07-06 Robin Louiset , Pietro Gori , Benoit Dufumier , Josselin Houenou , Antoine Grigis , Edouard Duchesnay

The premise of semi-supervised learning (SSL) is that combining labeled and unlabeled data yields significantly more accurate models. Despite empirical successes, the theoretical understanding of SSL is still far from complete. In this…

Machine Learning · Statistics 2024-09-06 Eyar Azar , Boaz Nadler

We present the use of self-supervised learning to explore and exploit large unlabeled datasets. Focusing on 42 million galaxy images from the latest data release of the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys, we…

Instrumentation and Methods for Astrophysics · Physics 2021-12-02 George Stein , Peter Harrington , Jacqueline Blaum , Tomislav Medan , Zarija Lukic

We have developed a method for detecting clusters in large imaging surveys, based on the detection of structures in galaxy density maps made in slices of photometric redshifts. This method was first applied to the Canada France Hawaii…

Background: Unsupervised machine learners have been increasingly applied to software defect prediction. It is an approach that may be valuable for software practitioners because it reduces the need for labeled training data. Objective:…

Software Engineering · Computer Science 2020-02-20 Ning Li , Martin Shepperd , Yuchen Guo
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