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Most cosmological parameter estimations are based on the same set of observations and are therefore not independent. Here, we test the consistency of parameter estimations using a combination of large-scale structure and supernovae data,…

Astrophysics · Physics 2009-11-10 Carolina Odman , Mike Hobson , Anthony Lasenby , Alessandro Melchiorri

It has been recently shown that a powerful way to constrain cosmological parameters from galaxy redshift surveys is to train graph neural networks to perform field-level likelihood-free inference without imposing cuts on scale. In…

Understanding how galaxy populations emerge and evolve from the growth of dark matter structure is a central challenge in galaxy formation theory. Semi-analytic models (SAMs) provide an efficient framework to address this problem, but…

Astrophysics of Galaxies · Physics 2026-05-05 Xuejie Li , Zhongxu Zhai , Xiaohu Yang , Andrew Benson , Yun Wang

In many research fields, the sizes of the existing datasets vary widely. Hence, there is a need for machine learning techniques which are well-suited for these different datasets. One possible technique is the self-organizing map (SOM), a…

Machine Learning · Computer Science 2020-01-09 Felix M. Riese , Sina Keller

XMM-Newton provides unprecedented insight into the X-ray Universe, recording variability information for hundreds of thousands of sources. Manually searching for interesting patterns in light curves is impractical, requiring an automated…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Miloš Kovačević , Mario Pasquato , Martino Marelli , Andrea De Luca , Ruben Salvaterra , Andrea Belfiore Mondoni

Using the Horizon-AGN hydrodynamical simulation and self-organising maps (SOMs), we show how to compress the complex data structure of a cosmological simulation into a 2-d grid which is much easier to analyse. We first verify the tight…

The calibration of redshift distributions for photometric samples using spectroscopic surveys is plagued by the difficulty in modelling the selection functions of spectroscopic surveys. In this work, we analyse how these selection functions…

Instrumentation and Methods for Astrophysics · Physics 2022-07-19 Isaac McMahon , Markus Michael Rau , Rachel Mandelbaum

Nowadays, with the advance of technology, there is an increasing amount of unstructured data being generated every day. However, it is a painful job to label and organize it. Labeling is an expensive, time-consuming, and difficult task. It…

Machine Learning · Computer Science 2020-06-25 Pedro H. M. Braga , Heitor R. Medeiros , Hansenclever F. Bassani

Physical parameters of galaxies (as luminosity, stellar mass, age) are often derived by means of the model templates which best fit their spectro-photometric data. We have performed a quantitative test aimed at exploring the ability of this…

Astrophysics · Physics 2010-11-11 Marcella Longhetti , Paolo Saracco , Arturo Mignano

A grand challenge of the 21st century cosmology is to accurately estimate the cosmological parameters of our Universe. A major approach to estimating the cosmological parameters is to use the large-scale matter distribution of the Universe.…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Siamak Ravanbakhsh , Junier Oliva , Sebastien Fromenteau , Layne C. Price , Shirley Ho , Jeff Schneider , Barnabas Poczos

Characterization of the redshift distribution of ensembles of galaxies is pivotal for large scale structure cosmological studies. In this work, we focus on improving the Self-Organizing Map (SOM) methodology for photometric redshift…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-05 A. Campos , B. Yin , S. Dodelson , A. Amon , A. Alarcon , C. Sánchez , G. M. Bernstein , G. Giannini , J. Myles , S. Samuroff , O. Alves , F. Andrade-Oliveira , K. Bechtol , M. R. Becker , J. Blazek , H. Camacho , A. Carnero Rosell , M. Carrasco Kind , R. Cawthon , C. Chang , R. Chen , A. Choi , J. Cordero , C. Davis , J. DeRose , H. T. Diehl , C. Doux , A. Drlica-Wagner , K. Eckert , T. F. Eifler , J. Elvin-Poole , S. Everett , X. Fang , A. Ferté , O. Friedrich , M. Gatti , D. Gruen , R. A. Gruendl , I. Harrison , W. G. Hartley , K. Herner , H. Huang , E. M. Huff , M. Jarvis , E. Krause , N. Kuropatkin , P. -F. Leget , N. MacCrann , J. McCullough , A. Navarro-Alsina , S. Pandey , J. Prat , M. Raveri , R. P. Rollins , A. Roodman , R. Rosenfeld , A. J. Ross , E. S. Rykoff , J. Sanchez , L. F. Secco , I. Sevilla-Noarbe , E. Sheldon , T. Shin , M. A. Troxel , I. Tutusaus , T. N. Varga , R. H. Wechsler , B. Yanny , Y. Zhang , J. Zuntz , M. Aguena , J. Annis , D. Bacon , S. Bocquet , D. Brooks , D. L. Burke , J. Carretero , F. J. Castander , M. Costanzi , L. N. da Costa , J. De Vicente , P. Doel , I. Ferrero , B. Flaugher , J. Frieman , J. García-Bellido , E. Gaztanaga , G. Gutierrez , S. R. Hinton , D. L. Hollowood , K. Honscheid , D. J. James , K. Kuehn , M. Lima , H. Lin , J. L. Marshall , J. Mena-Fernández , F. Menanteau , R. Miquel , R. L. C. Ogando , M. Paterno , M. E. S. Pereira , A. Pieres , A. A. Plazas Malagón , A. Porredon , E. Sanchez , D. Sanchez Cid , M. Smith , E. Suchyta , M. E. C. Swanson , G. Tarle , C. To , V. Vikram , N. Weaverdyck

We derive physical parameters of galaxies from their observed spectrum, using MOPED, the optimized data compression algorithm of Heavens, Jimenez & Lahav 2000. Here we concentrate on parametrising galaxy properties, and apply the method to…

Astrophysics · Physics 2009-11-06 Christian Reichardt , Raul Jimenez , Alan Heavens

Multi-dimensional data classification is an important and challenging problem in many astro-particle experiments. Neural networks have proved to be versatile and robust in multi-dimensional data classification. In this article we shall…

Neural and Evolutionary Computing · Computer Science 2007-05-23 P. Boinee , F. Barbarino , A. De Angelis

Continuous monitoring with an ever-increasing number of sensors has become ubiquitous across many application domains. However, acquired time series are typically high-dimensional and difficult to interpret. Expressive deep learning (DL)…

Machine Learning · Computer Science 2023-05-26 Iris A. M. Huijben , Arthur A. Nijdam , Sebastiaan Overeem , Merel M. van Gilst , Ruud J. G. van Sloun

We present an automatic classification method for astronomical catalogs with missing data. We use Bayesian networks, a probabilistic graphical model, that allows us to perform inference to pre- dict missing values given observed data and…

Instrumentation and Methods for Astrophysics · Physics 2013-10-30 Karim Pichara , Pavlos Protopapas

Image feature classification is a challenging problem in many computer vision applications, specifically, in the fields of remote sensing, image analysis and pattern recognition. In this paper, a novel Self Organizing Map, termed improved…

Computer Vision and Pattern Recognition · Computer Science 2015-01-09 M. Abdelsamea , Marghny H. Mohamed , Mohamed Bamatraf

Classification networks can be used to localize and segment objects in images by means of class activation maps (CAMs). However, without pixel-level annotations, classification networks are known to (1) mainly focus on discriminative…

Computer Vision and Pattern Recognition · Computer Science 2023-04-05 Arvi Jonnarth , Michael Felsberg

Photometric surveys have provided incredible amounts of astronomical information in the form of images. However, astronomical images often contain artifacts that can critically hinder scientific analysis by misrepresenting intensities or…

Instrumentation and Methods for Astrophysics · Physics 2020-06-03 Suchetha Cooray , Tsutomu T. Takeuchi , Moe Yoda , Kazuo Sorai

Over the next decade, improvements in cosmological parameter constraints will be driven by surveys of large-scale structure. Its inherent non-linearity suggests that significant information will be embedded in higher correlations beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Joyce Byun , Alexander Eggemeier , Donough Regan , David Seery , Robert E. Smith

The statistical description of Giant Molecular Cloud (GMC) properties relies heavily on the performance of automatic identification algorithms, which are often seriously affected by the survey design. The algorithm we designed, SCIMES…

Astrophysics of Galaxies · Physics 2017-01-11 Dario Colombo , Erik Rosolowsky , Adam Ginsburg , Ana Duarte-Cabral , Annie Hughes