English
Related papers

Related papers: GRASS II: Simulations of Potential Granulation Noi…

200 papers

We use full sky simulations, including the effects of foreground contamination and removal, to explore multi-tracer synergies between a SKA-like 21cm intensity mapping survey and a LSST-like photometric galaxy redshift survey. In particular…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-27 Amadeus Witzemann , David Alonso , José Fonseca , Mario G. Santos

We present a new iterative rotation inversion technique based on the Simultaneous Algebraic Reconstruction Technique developed for image reconstruction. We describe in detail our algorithmic implementation and compare it to the classical…

Solar and Stellar Astrophysics · Physics 2024-06-17 Sylvain G. Korzennik , Antonio Eff-Darwich

In the surface layers of late-type stars, stellar convection is manifested with its typical granulation pattern due to the presence of convective motions. The resulting photospheric up- and downflows leave imprints in the observed spectral…

Solar and Stellar Astrophysics · Physics 2014-05-30 Zazralt Magic , Martin Asplund

Using a recently developed two-scale formalism to determine the magnetic helicity spectrum (Brandenburg et al. 2017), we analyze synoptic vector magnetograms built with data from the Vector Spectromagnetograph (VSM) instrument on the…

Solar and Stellar Astrophysics · Physics 2019-01-14 Nishant K. Singh , Maarit J. Käpylä , Axel Brandenburg , Petri J. Käpylä , Andreas Lagg , Ilpo Virtanen

The dynamics in the photosphere is governed by the multi-scale turbulent convection termed as granulation and supergranulation. It is important to derive 3-dimensional velocity vectors to understand the nature of the turbulent convection.…

Solar and Stellar Astrophysics · Physics 2022-03-14 Ryohtaroh T. Ishikawa , Motoki Nakata , Yukio Katsukawa , Youhei Masada , Tino L. Riethmüller

Purpose: Develop a processing scheme for Gradient Echo (GRE) phase to enable restoration of susceptibility-related (SuR) features in regions affected by imperfect phase unwrapping, background suppression and low signal-to-noise ratio (SNR)…

Medical Physics · Physics 2021-06-30 Joseph Suresh Paul , Sreekanth Madhusoodhanan

We report evidence for the granulation signal in the star Procyon A, based on two photometric time series from the star tracker on the WIRE satellite. The power spectra show evidence of excess power around 1 milliHz, consistent with the…

Astrophysics · Physics 2009-11-11 H. Bruntt , H. Kjeldsen , D. L. Buzasi , T. R. Bedding

Different stellar phenomena affect radial velocities (RVs), causing variations large enough to make it difficult to identify planet signals from the stellar variability. RV variations caused by stellar oscillations and granulation can be…

We present an analysis of suitable rotation curves (RCs) of eight galaxies, aimed at checking the consistency and universality of the gravitational suppression (GraS) hypothesis, a phenomenological model for a new interaction between dark…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christiane Frigerio Martins , Paolo Salucci

This work presents inGRASS, a novel algorithm designed for incremental spectral sparsification of large undirected graphs. The proposed inGRASS algorithm is highly scalable and parallel-friendly, having a nearly-linear time complexity for…

Data Structures and Algorithms · Computer Science 2024-09-09 Ali Aghdaei , Zhuo Feng

Inverse problems in imaging are ill-posed, leading to infinitely many solutions consistent with the measurements due to the non-trivial null-space of the sensing matrix. Common image priors promote solutions on the general image manifold,…

Computer Vision and Pattern Recognition · Computer Science 2026-04-17 Romario Gualdrón-Hurtado , Roman Jacome , Rafael S. Suarez , Henry Arguello

Stellar micro-variability poses a serious threat to the capacities of space-based planet-finding missions such as Kepler or Eddington. The solar lightcurves obtained by the VIRGO PMO6 and SPM instruments on board SoHO from 1996 to 2001 have…

Astrophysics · Physics 2007-05-23 S. Aigrain , G. Gilmore , F. Favata , S. Carpano

A new procedure for smoothing a gamma-ray burst (GRB) lightcurve and calculating its variability is presented. Applying the procedure to a sample of 25 long GRBs, we have obtained a very tight correlation between the variability and the…

Astrophysics · Physics 2009-11-13 Li-Xin Li , Bohdan Paczynski

Context. The surface structures and dynamics of cool stars are characterized by the presence of convective motions and turbulent flows which shape the emergent spectrum. Aims. We used realistic three-dimensional radiative hydrodynamical…

Solar and Stellar Astrophysics · Physics 2018-03-14 A. Chiavassa , L. Casagrande , R. Collet , Z. Magic , L. Bigot , F. Thevenin , M. Asplund

Refractive interstellar scintillation (RISS) is thought to be the cause behind a variety of phenomena seen at radio wavelengths in pulsars and compact radio sources. Though there is substantial observational data to support several…

Astrophysics · Physics 2009-10-31 N. D. Ramesh Bhat , A. Pramesh Rao , Yashwant Gupta

Time series segmentation (TSS) is one of the time series (TS) analysis techniques, that has received considerably less attention compared to other TS related tasks. In recent years, deep learning architectures have been introduced for TSS,…

Machine Learning · Computer Science 2026-02-20 Ivana Kesić , Carolina Fortuna , Mihael Mohorčič , Blaž Bertalanič

Precise Soil Moisture (SM) assessment is essential in agriculture. By understanding the level of SM, we can improve yield irrigation scheduling which significantly impacts food production and other needs of the global population. The…

Computer Vision and Pattern Recognition · Computer Science 2023-03-22 Muhammad Riaz Hasib Hossain , Muhammad Ashad Kabir

The granulation of red supergiants (RSGs) in the Magellanic Clouds are systematically investigated by combining the latest RSGs samples and light curves from the Optical Gravitational Lensing Experiment and the All-Sky Automated Survey for…

Solar and Stellar Astrophysics · Physics 2024-05-03 Zehao Zhang , Yi Ren , Biwei Jiang , Igor Soszynski , Tharindu Jayasinghe

Stellar variability strongly impacts the search for low-mass exoplanets with radial velocity techniques. Two types of planet-free time series can be used to quantify this impact: models and direct solar observations after a subtraction of…

Solar and Stellar Astrophysics · Physics 2024-05-20 Nadège Meunier , Anne-Marie Lagrange , Xavier Dumusque , Sophia Sulis

The next generation of gravitational-wave observatories will achieve unprecedented strain sensitivities with an expanded observing band. They will detect ${\cal O}(10^5)$ binary neutron star (BNS) mergers every year, the loudest of which…

General Relativity and Quantum Cosmology · Physics 2025-11-17 A. Makai Baker , Paul D. Lasky , Eric Thrane , Jacob Golomb