Results 41 to 50 of about 119 (87)

Exploring Magnetic Fields in Molecular Clouds through Denoising Diffusion Probabilistic Models

The Astrophysical Journal
Accurately measuring magnetic field strength in the interstellar medium, including giant molecular clouds, remains a significant challenge. We present a machine learning approach using denoising diffusion probabilistic models (DDPMs) to estimate magnetic
Duo Xu, Jenna Karcheski, Chi-Yan Law, Ye Zhu, Chia-Jung Hsu, Jonathan C. Tan   +5 more
doaj   +1 more source

Rare Event Classification with Weighted Logistic Regression for Identifying Repeating Fast Radio Bursts

The Astrophysical Journal
An important task in the study of fast radio bursts (FRBs) remains the automatic classification of repeating and nonrepeating sources based on their morphological properties. We propose a statistical model that considers a modified logistic regression to
Antonio Herrera-Martin, Radu V. Craiu, Gwendolyn M. Eadie, David C. Stenning, Derek Bingham, B. M. Gaensler, Ziggy Pleunis, Paul Scholz, Ryan Mckinven, Bikash Kharel, Kiyoshi W. Masui   +10 more
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Distributions of Wide Binary Stars in Theory and in Gaia Data. II. Reconstruction of Sample Probability Density of True Orbit Sizes

The Astronomical Journal
Wide binary stars are important for testing alternative models of gravitation in the weak-field regime and understanding the statistical outcomes of dynamical interactions in the general Galactic field. The Gaia mission’s collection of weakly bound pairs
Valeri V. Makarov
doaj   +1 more source

Robustness Analysis of USmorph. I. Generalization Efficiency of Unsupervised Strategies and Supervised Learning in Galaxy Morphological Classification

The Astrophysical Journal
We conduct a systematic robustness analysis of the hybrid machine learning framework USmorph , which integrates unsupervised and supervised learning for galaxy morphological classification.
Shiwei Zhu, Guanwen Fang, Yao Dai, Chichun Zhou, Yirui Zheng, Jie Song, Shiying Lu, Xu Kong   +7 more
doaj   +1 more source

USmorph: An Updated Framework of Automatic Classification of Galaxy Morphologies and Its Application to Galaxies in the COSMOS Field

The Astrophysical Journal Supplement Series
Morphological classification conveys abundant information on the formation, evolution, and environment of galaxies. In this work, we refine a two-step galaxy morphological classification framework ( USmorph ), which employs a combination of unsupervised ...
Jie Song, GuanWen Fang, Shuo Ba, Zesen Lin, Yizhou Gu, Chichun Zhou, Tao Wang, Cai-Na Hao, Guilin Liu, Hongxin Zhang, Yao Yao, Xu Kong   +11 more
doaj   +1 more source

Advanced Spatial Methods for Astrophysics [PDF]

Ultra-Diffuse Galaxies (UDGs) are faint, extended systems with extremely low surface brightness and large physical sizes that challenge standard galaxy formation models. Despite their faintness, many UDGs host numerous globular clusters (GCs) --- massive
Li, Dayi
core   +1 more source

Dual-coding Contrastive Learning Based on the ConvNeXt and ViT Models for Morphological Classification of Galaxies in COSMOS-Web

The Astrophysical Journal Supplement Series
In our previous works, we proposed a machine learning framework named USmorph for efficiently classifying galaxy morphology. In this study, we propose a self-supervised method called contrastive learning to upgrade the unsupervised machine learning (UML)
Shiwei Zhu, Guanwen Fang, Chichun Zhou, Jie Song, Zesen Lin, Yao Dai, Xu Kong   +6 more
doaj   +1 more source

Robustness Analysis of USmorph. II. Optimizing Feature Extraction, Dimensionality Reduction, and Clustering for Unsupervised Galaxy Morphology Classification

The Astrophysical Journal
We conduct a systematic robustness analysis of the unsupervised machine learning module within the hybrid framework USmorph . This module automatically discovers morphological structures from large-scale galaxy images, forming the foundation of the ...
Guanwen Fang, Xiaolei Yin, Yirui Zheng, Zesen Lin, Shiwei Zhu, Jie Song, Chichun Zhou, Xu Kong   +7 more
doaj   +1 more source

A Parameter-masked Mock Data Challenge for Beyond-two-point Galaxy Clustering Statistics

The Astrophysical Journal
The past 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 and the ...
The Beyond-2pt Collaboration, Elisabeth Krause, Yosuke Kobayashi, Andrés N. Salcedo, Mikhail M. Ivanov, Tom Abel, Kazuyuki Akitsu, Raul E. Angulo, Giovanni Cabass, Sofia Contarini, Carolina Cuesta-Lazaro, ChangHoon Hahn, Nico Hamaus, Donghui Jeong, Chirag Modi, Nhat-Minh Nguyen, Takahiro Nishimichi, Enrique Paillas, Marcos Pellejero Ibañez, Oliver H. E. Philcox, Alice Pisani, Fabian Schmidt, Satoshi Tanaka, Giovanni Verza, Sihan Yuan, Matteo Zennaro   +25 more
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Influence of Density Distribution on Synchrotron Polarization Dispersion in Magnetized Interstellar Medium

The Astrophysical Journal
Faraday rotation measure (RM) synthesis is a well-known approach originated in B. J. Burn and later developed by M. A. Brentjens & A. G. de Bruyn for studying magnetic fields.
Ya-Wen Xiao, Jian-Fu Zhang, Alex Lazarian, Dmitri Pogosyan   +3 more
doaj   +1 more source