中文
相关论文

相关论文: Two Practical Methods for Coronal Intensity Determ…

200 篇论文

Decayless kink oscillations of plasma loops in the solar corona may contain an answer to the enigmatic problem of solar and stellar coronal heating. The polarisation of the oscillations gives us a unique information about their excitation…

Using a Monte Carlo ray-tracing code in full general relativity, we calculate the transport of photons from a geodesic hot spot emitter through a corona of hot electrons surrounding a black hole. Each photon is followed until it is either…

天体物理学 · 物理学 2007-05-23 Jeremy D. Schnittman

Daily differential emission measure (DEM) distributions of the solar corona are derived from spectra obtained by the Extreme-ultraviolet Variability Experiment (EVE) over a 4-year period starting in 2010 near solar minimum and continuing…

太阳与恒星天体物理 · 物理学 2020-09-16 Samuel J. Schonfeld , Stephen M. White , Rachel A. Hock-Mysliwiec , R. T. James McAteer

We propose an algorithm that can be used by amateur astronomers to analyze the images acquired during solar eclipses. The proposed algorithm analyzes the image, detects the eclipse and produces results for parameters like magnitude of…

地球与行星天体物理 · 物理学 2012-06-08 Sarrvesh Seethapuram Sridhar , S. Pradeep Sundar , I. Kenny Jackson , P. Kannan

Stokes polarimetry (SP) is a powerful technique that enables spatial reconstruction of the state of polarization (SoP) of a light beam using only intensity measurements. A given SoP is reconstructed from a set of four Stokes parameters,…

Intending to solve the decade old problem of solar opacity, we report substantial photoabsorption uncertainty due to the effect of ion-ion correlations. By performing detailed opacity calculations of the solar mixture, we find that taking…

太阳与恒星天体物理 · 物理学 2018-03-01 Menahem Krief , Yair Kurzweil , Alexander Feigel , Doron Gazit

In solar flares, inverse Compton scattering (ICS) of photospheric photons might give rise to detectable hard X-ray photon fluxes from the corona where ambient densities are too low for significant bremsstrahlung or recombination. Gamma-ray…

太阳与恒星天体物理 · 物理学 2015-05-14 Alec L. MacKinnon , Procheta C. V. Mallik

Understanding the 3D structure of coronal mass ejections (CMEs) is crucial for understanding the nature and origin of solar eruptions. To derive information on the 3D structure of CMEs from white-light (total and polarized brightness)…

太阳与恒星天体物理 · 物理学 2015-10-14 Paolo Pagano , Alessandro Bemporad , Duncan Mackay

The solar atmosphere is filled with clusters of hot small-scale loops commonly known as Coronal Bright Points (CBPs). These ubiquitous structures stand out in the Sun by their strong X-ray and/or extreme-ultraviolet (EUV) emission for hours…

太阳与恒星天体物理 · 物理学 2024-06-14 D. Nóbrega-Siverio , F. Moreno-Insertis , K Galsgaard , K. Krikova , L. Rouppe van der Voort , R. Joshi , M. S. Madjarska

We present a unified method to derive both solar wind velocities and coronal electron densities in the near-Sun corona using Doppler spectral broadening of spacecraft radio signals. The method is generalized to be frequency independent…

太阳与恒星天体物理 · 物理学 2026-03-26 Keshav Aggarwal , R. K. Choudhary , Abhirup Datta , Roopa M. V. , Takeshi Imamura , Hiroki Ando

A simple, self-calibrating, rotating-waveplate polarimeter is largely insensitive to light intensity fluctuations and is shown to be useful for determining the Stokes parameters of light. This study shows how to minimize the in situ…

光学 · 物理学 2021-11-16 Vitaly Wirthl , Cristian D. Panda , Paul W. Hess , Gerald Gabrielse

The temperatures of the heavy ions ($T_i$) in the solar corona provide critical information about the heating mechanism of the million-degree corona. However, the measurement of $T_i$ is usually challenging due to the nonthermal motion,…

太阳与恒星天体物理 · 物理学 2023-05-17 Yingjie Zhu , Judit Szente , Enrico Landi

We discuss the diagnostics available to study the 5-10 MK plasma in the solar corona, which is key to understanding the heating in the cores of solar active regions. We present several simulated spectra, and show that excellent diagnostics…

太阳与恒星天体物理 · 物理学 2021-03-11 G. Del Zanna , V. Andretta , P. J. Cargill , A. J. Corso , A. N. Daw , L. Golub , J. A. Klimchuk , H. E. Mason

We present an ab initio approach to the solar coronal heating problem by modelling a small part of the solar corona in a computational box using a 3D MHD code including realistic physics. The observed solar granular velocity pattern and its…

天体物理学 · 物理学 2009-11-10 B. V. Gudiksen , Å. Nordlund

The composition of the solar corona differs from that of the photosphere, with the plasma thought to fractionate in the solar chromosphere according to the First Ionisation Potential (FIP) of the different elements. This produces a FIP…

A turbulent dynamo in spherical geometry with an outer corona is simulated to study the sign of magnetic helicity in the outer parts. In agreement with earlier studies, the sign in the outer corona is found to be opposite to that inside the…

太阳与恒星天体物理 · 物理学 2017-08-18 Axel Brandenburg , Mohira B. Ashurova , Sarah Jabbari

We study $e^{\pm}$ pair plasmas in pair equilibrium, which emit high energy radiation by thermal Comptonization of soft photons. We find that the maximum luminosity to size ratio of the source (i.e. the compactness) depends not only on the…

天体物理学 · 物理学 2009-10-22 Gabriele Ghisellini , Francesco Haardt

Well-known analytical results dealing with ion cyclotron and drift waves and which follow from the kinetic theory are used and the dispersion equation, which describes coupled two modes, is solved numerically. The numerical results obtained…

天体物理学 · 物理学 2009-11-13 J. Vranjes , S. Poedts

An application of active contours without edges is presented as an efficient and effective means of extracting and characterizing coronal holes. Coronal holes are regions of low-density plasma on the Sun with open magnetic field lines. As…

太阳与恒星天体物理 · 物理学 2016-10-05 L. E. Boucheron , M. Valluri , R. T. J. McAteer

Solar flare electron acceleration is an efficient process, but its properties (mechanism, location) are not well constrained. Via hard X-ray (HXR) emission, we routinely observe energetic electrons at the Sun, and sometimes we detect…

太阳与恒星天体物理 · 物理学 2023-10-09 Ross Pallister , Natasha L. S. Jeffrey