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Related papers: Identifying Acoustic Wave Sources on the Sun. II. …

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We show that under certain conditions, subsurface structures in the solar interior can alter the average acoustic power observed at the photosphere above them. By using numerical simulations of wave propagation, we show that this effect is…

Solar and Stellar Astrophysics · Physics 2015-05-18 Thomas Hartlep , Alexander G. Kosovichev , Junwei Zhao , Nagi N. Mansour

Helioseismic holography is an imaging technique used to study heterogeneities and flows in the solar interior from observations of solar oscillations at the surface. Holograms contain noise due to the stochastic nature of solar…

Solar and Stellar Astrophysics · Physics 2018-12-12 Laurent Gizon , Damien Fournier , Dan Yang , Aaron C. Birch , Hélène Barucq

Observations of the Sun in the visible spectral range belong to standard measurements obtained by instruments both on the ground and in the space. Nowadays, both nearly continuous full-disc observations with medium resolution and dedicated…

Solar and Stellar Astrophysics · Physics 2020-06-30 Michal Švanda , Jan Jurčák , David Korda , Jana Kašparová

Sunspots are prominent manifestations of solar magnetoconvection and imaging their subsurface structure is an outstanding problem of wide physical importance. Travel times of seismic waves that propagate through these structures are…

Solar and Stellar Astrophysics · Physics 2015-06-05 Shravan Hanasoge , Aaron Birch , Laurent Gizon , Jeroen Tromp

Previous studies analyzing the evanescent nature of acoustic waves in the lower solar atmosphere, up to 300\,km above the photosphere, have shown an unexpected phase shift of an order of 1\,s between different heights. Those studies…

Solar and Stellar Astrophysics · Physics 2023-06-14 M. Waidele , Junwei Zhao , I. N. Kitiashvili

Solar models computed with mass loss, microscopic diffusion of helium and heavy elements and with updated physics have been evolved from the pre-main sequence to present days; they are compared to the observational constraints including…

Astrophysics · Physics 2007-05-23 P. Morel , J. Provos , G. Berthomieu

This paper provides a framework for the incorporation of the wavefront sensor measurements in the context of observing modes in which the science camera takes millisecond exposures. In this formulation, the wavefront sensor measurements…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Richard A. Frazin

We extend an existing Born approximation method for calculating the linear sensitivity of helioseismic travel times to flows from Cartesian to spherical geometry. This development is necessary for using the Born approximation for inferring…

Solar and Stellar Astrophysics · Physics 2016-06-15 Vincent G. A. Böning , Markus Roth , Wolfgang Zima , Aaron C. Birch , Laurent Gizon

Context: Helioseismology aims to infer the properties of the solar interior by analyzing observations of acoustic oscillations. The interpretation of the helioseismic data is however complicated by the non-trivial relationship between…

Solar and Stellar Astrophysics · Physics 2025-10-29 D. Fournier , N. M. Kostogryz , L. Gizon , J. Schou , V. Witzke , A. I. Shapiro , I. Milic

We present two new source extraction methods, based on Bayesian model selection and using the Bayesian Information Criterion (BIC). The first is a source detection filter, able to simultaneously detect point sources and estimate the image…

Astrophysics · Physics 2011-02-11 Richard S. Savage , Seb Oliver

In helioseismology, there is a well-known offset between observed and computed oscillation frequencies. This offset is known to arise from improper modeling of the near-surface layers of the Sun, and a similar effect must occur for models…

Astrophysics · Physics 2009-11-13 Hans Kjeldsen , Timothy R. Bedding , Joergen Christensen-Dalsgaard

We introduce wavefront shaping as a tool for optimizing the sensitivity in nano-optomechanical measurement schemes. We perform multimode output analysis of an optomechanical system consisting of a focused laser beam coupled to the…

The Solar Orbiter mission, to be launched in July 2017, will carry a suite of remote sensing and in-situ instruments, including the Polarimetric and Helioseismic Imager (PHI). PHI will deliver high-cadence images of the Sun in intensity and…

We have imaged a $\sim$6 arcminute$^2$ region in the Bo\"otes Deep Field using the 350 $\mu$m-optimised second generation Submillimeter High Angular Resolution Camera (SHARC II), achieving a peak 1$\sigma$ sensitivity of $\sim$5 mJy. We…

We have developed a general data reduction technique for ISOCAM data coming from various deep surveys of faint galaxies. In order to reach the fundamental limits of the camera (due to the background photon noise and the readout noise), we…

In this article we consider the detection of compact sources in maps of the Cosmic Microwave Background radiation (CMB) following the philosophy behind the Mexican Hat Wavelet Family (MHWn) of linear filters. We present a new analytical…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 M. López-Caniego , P. Vielva

Being able to image active regions on the Sun's far side is useful for modeling the global-scale magnetic field around the Sun, and for predicting the arrival of major active regions that rotate around the limb onto the near side.…

Solar and Stellar Astrophysics · Physics 2020-01-08 Junwei Zhao , Dominick Hing , Ruizhu Chen , Shea Hess Webber

We infer the depth of the internal sources giving rise to three-minute umbral oscillations. Recent observations of ripple-like velocity patterns of umbral oscillations supported the notion that there exist internal sources exciting the…

Solar and Stellar Astrophysics · Physics 2020-04-15 Kyuhyoun Cho , Jongchul Chae

Recent work published by Lindsey et al find evidence for a deep and compact seismic source for the sunquake associated with the 2011 July 30 M9.3 flare, as well as seismic emission extending up to 10 mHz. We examine the sunquake…

Solar and Stellar Astrophysics · Physics 2022-10-05 John T. Stefan , Alexander G. Kosovichev

We present a study of multi-wavelength observations, of a C 2.3 solar flare in Active Region NOAA 12353, observed on 2015 May 23, which reveal new properties of acoustic waves in the flaring region. The space-, and ground-based data…

Solar and Stellar Astrophysics · Physics 2022-03-07 A. Wisniewska , E. Chmielewska , K. Radziszewski , M. Roth , J. Staiger