Results 51 to 60 of about 502 (78)

Using R-based VOStat as a Low-Resolution Spectrum Analysis Tool [PDF]

We describe here an online software suite VOStat written mainly for the Virtual Observatory, a novel structure in which astronomers share terabyte scale data. Written mostly in the public-domain statistical computing language and environment R, it can do
Ashish Mahabal, Jogesh G. Babu
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. 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

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

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
doaj   +1 more source

CatNorth: An Improved Gaia DR3 Quasar Candidate Catalog with Pan-STARRS1 and CatWISE

The Astrophysical Journal Supplement Series
A complete and pure sample of quasars with accurate redshifts is crucial for quasar studies and cosmology. In this paper, we present CatNorth, an improved Gaia Data Release 3 (Gaia DR3) quasar candidate catalog with more than 1.5 million sources in the 3
Yuming Fu, Xue-Bing Wu, Yifan Li, Yuxuan Pang, Ravi Joshi, Shuo Zhang, Qiyue Wang, Jing Yang, FanLam Ng, Xingjian Liu, Yu Qiu, Rui Zhu, Huimei Wang, Christian Wolf, Yanxia Zhang, Zhi-Ying Huo, Y. L. Ai, Qinchun Ma, Xiaotong Feng, R. J. Bouwens   +19 more
doaj   +1 more source

Discovery of Radial Spectral Hardening in the Hot Bubble of Planetary Nebula BD+30°3639 with Median Energy Imaging

The Astrophysical Journal
We apply an imaging analysis technique to study the spatial distribution of the X-ray spectral hardness across the hot bubble of planetary nebula BD+30°3639.
Rodolfo Montez Jr.
doaj   +1 more source

Singular Spectrum Analysis of Exoplanetary Transits

The Astronomical Journal
Transit photometry is currently the most efficient and sensitive method for detecting extrasolar planets (exoplanets) and a large majority of confirmed exoplanets have been detected with this method.
Hossein Fatheddin, Sedighe Sajadian
doaj   +1 more source

Different Planetary Eccentricity-period (PEP) Distributions of Small and Giant Planets

The Astronomical Journal
We used the database of 1040 short-period (1 ≤ P < 200 days) exoplanets radial-velocity orbits to study the planetary eccentricity-period (PEP) distribution.
Dolev Bashi, Tsevi Mazeh, Simchon Faigler   +2 more
doaj   +1 more source