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At high frequencies beyond the acoustic cut-off, a peak-like structure is visible in the solar power spectrum. Known as the pseudo-modes, their frequencies have been shown to vary in anti-phase with solar magnetic activity. In this work, we…

Solar and Stellar Astrophysics · Physics 2024-09-06 Laura Jade Millson , Anne-Marie Broomhall , Tishtrya Mehta

The NASA PACE mission provides unprecedented hyperspectral observations of ocean color, aerosols, and clouds, offering new insights into how these components interact and influence Earth's climate and air quality. Its Ocean Color Instrument…

Computer Vision and Pattern Recognition · Computer Science 2026-04-24 Zahid Hassan Tushar , Sanjay Purushotham

21cm tomography promises to be a powerful tool for estimating cosmological parameters, constraining the epoch of reionization, and probing the so-called dark ages. However, realizing this promise will require the extraction of a…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Adrian Liu , Max Tegmark

We apply the variational autoencoder (VAE) to the LAMOST-K2 low-resolution spectra to detect the magnetic activity of the stars in the K2 field. After the training on the spectra of the selected inactive stars, the VAE model can efficiently…

Solar and Stellar Astrophysics · Physics 2022-07-07 Yue Xiang , Shenghong Gu , Dongtao Cao

In our previous articles (Chertok et al.: 2013, Solar Phys. 282, 175, and 2015, Solar Phys. 290, 627), we presented a preliminary tool for the early diagnostics of the geoeffectiveness of solar eruptions based on the estimate of the total…

Solar and Stellar Astrophysics · Physics 2017-04-19 I. M. Chertok , V. V. Grechnev , A. A. Abunin

Near-infrared imaging is a powerful technique in observational astronomy, but the bright background, primarily from the Earth\'s atmosphere, makes the detection of faint features particularly challenging. To recover low surface brightness…

Instrumentation and Methods for Astrophysics · Physics 2025-08-06 Elham Saremi , Ignacio Trujillo , Mohammad Akhlaghi , Zohreh Ghaffari , Johan H. Knapen , Manda Banerji , Helmut Dannerbauer , Sébastien Comerón

The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun's surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well…

Solar and Stellar Astrophysics · Physics 2025-05-05 James Crowley , Ivan Milic , Gianna Cauzzi , Kevin Reardon

The unsigned mean magnetic field characterizes the magnetic energy settled in the region near the solar surface. It is one of the determinant ingredients that govern the turbulence in the photosphere, and the magnetic heating of upper…

Astrophysics · Physics 2007-05-23 P. A. P. Nghiem , R. A. Garcia , S. J. Jimenez-Reyes

Unconditional and conditional statistics is used for studying the histograms of magnetic field multi-scale fluctuations in the solar wind near the solar cycle minimum in 2008. The unconditional statistics involves the magnetic data during…

Space Physics · Physics 2015-10-01 Vörös , Z. , M. Leitner , Y. Narita , G. Consolini , P. Kovács , A. Tóth , J. Lichtenberger

Light beams can be characterized by their complex spatial profiles in both intensity and phase. Analogous to time signals, which can be decomposed into multiple orthogonal frequency functions, a light beam can also be decomposed into a set…

Several works have reported changes of the Sun's subsurface stratification inferred from f-mode or p-mode observations. Recently a non-homologous variation of the subsurface layers with depth and time has been deduced from f-modes. Progress…

Astrophysics · Physics 2011-02-11 Sandrine Lefebvre , Phu Anh Phi Nghiem , Sylvaine Turck-Chieze

Background subtraction has been a driving engine for many computer vision and video analytics tasks. Although its many variants exist, they all share the underlying assumption that photometric scene properties are either static or exhibit…

Computer Vision and Pattern Recognition · Computer Science 2009-10-16 P. M. Jodoin , V. Saligrama , J. Konrad

The Solar Dynamics Observatory (SDO), launched in 2010 as part of NASA's Living With a Star (LWS) program, represents a methodological transition in heliophysics: from identifying discrete solar events to characterizing the continuously…

Solar and Stellar Astrophysics · Physics 2026-05-25 Madhulika Guhathakurta

Generation and diffusion of the magnetic field on the Sun is a key mechanism responsible for solar activity on all spatial and temporal scales - from the solar cycle down to the evolution of small-scale magnetic elements in the quiet Sun.…

Solar and Stellar Astrophysics · Physics 2011-12-14 V. I. Abramenko , V. B. Yurchyshyn , P. R. Goode

Segment Anything Model (SAM), known for its remarkable zero-shot segmentation capabilities, has garnered significant attention in the community. Nevertheless, its performance is challenged when dealing with what we refer to as visually…

Computer Vision and Pattern Recognition · Computer Science 2026-01-05 Guangqian Guo , Pengfei Chen , Yong Guo , Huafeng Chen , Boqiang Zhang , Shan Gao

The Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) returns high-resolution images of the solar atmosphere in seven extreme ultraviolet (EUV) wavelength channels. The images are processed on the ground to…

Solar and Stellar Astrophysics · Physics 2022-01-05 Peter R. Young , Nicholeen M. Viall , Michael S. Kirk , Emily I. Mason , Lakshmi Pradeep Chitta

We use SDO/HMI and SOLIS/VSM photospheric magnetic field measurements to model the force-free coronal field above a solar active region, assuming magnetic forces to dominate. We take measurement uncertainties caused by, e.g., noise and the…

Solar and Stellar Astrophysics · Physics 2015-06-05 J. K. Thalmann , A. Pietarila , X. Sun , T. Wiegelmann

We used the Pixelised Wavelet Filtering (PWF) method to compute narrow-band power maps of SDO/AIA imaging datasets in the 1700 \AA{}, 1600 \AA{} and 304 \AA{} bandpasses that correspond to different heights. The cut-off frequency was…

Solar and Stellar Astrophysics · Physics 2014-04-15 Ding Yuan , R. Sych , V. E. Reznikova , V. M. Nakariakov

We present new data processing techniques that allow to correct the main instrumental effects that degrade the images obtained by ISOCAM, the camera on board the Infrared Space Observatory (ISO). Our techniques take advantage of the fact…

Astrophysics · Physics 2009-10-31 M. -A. Miville-Deschenes , F. Boulanger , A. Abergel , J. -P. Bernard

We present a statistical technique which can be used to detect the presence and properties of moving sources contributing to a diffuse background. The method is a generalization of the 2-point correlation function to include temporal as…

High Energy Astrophysical Phenomena · Physics 2015-03-17 Alex Geringer-Sameth , Savvas M. Koushiappas
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