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Related papers: Where the granular flows bend

200 papers

Magnetic reconnection is believed to be the dominant energy release mechanism in solar flares. The standard flare model predicts both downward and upward outflow plasmas with speeds close to the coronal Alfv\'{e}n speed. Yet, spectroscopic…

Solar and Stellar Astrophysics · Physics 2014-12-02 Hui Tian , Gang Li , Katharine K. Reeves , John C. Raymond , Fan Guo , Wei Liu , Bin Chen , Nicholas A. Murphy

Upflows observed at the edges of active regions have been proposed as the source of the slow solar wind. In the particular case of Active Region (AR) 10942, where such an upflow has been already observed, we want to evaluate the part of…

Solar and Stellar Astrophysics · Physics 2016-05-11 Céline Boutry , Eric Buchlin , Jean-Claude Vial , Stéphane Régnier

We present observations of the quiet solar photosphere in the \ion{Fe}{1} lines at 6302 \AA where at least four different spatial locations exhibit upwards-directed supersonic flows. These upflows can only be detected in the circular…

Astrophysics · Physics 2009-11-10 H. Socas-Navarro , R. Manso

Observations find that some fast radio bursts (FRBs) have extremely narrow-band spectra, i.e., $\Delta\nu/\nu_0 \ll 1$. We show that when the angular size of the emission region is larger than the Doppler beaming angle, the observed…

High Energy Astrophysical Phenomena · Physics 2024-08-14 Pawan Kumar , Yuanhong Qu , Bing Zhang

In this paper, the physical conditions within the inhomogeneous solar atmosphere have been reconstructed by means of solving the inverse problem of Non Local Thermodynamic Equilibrium (NLTE) radiative transfer. The profiles of…

Astrophysics · Physics 2008-11-26 M. I. Stodilka , S. Z. Malynych

Using high-resolution spectropolarimetric data recorded with the Swedish 1 m Solar Telescope, we have identified several instances of granular lanes traveling into granules. These are believed to be the observational signature of underlying…

Solar and Stellar Astrophysics · Physics 2020-11-11 C. E. Fischer , G. Vigeesh , P. Lindner , J. M. Borrero , F. Calvo , O. Steiner

A weak fluctuating magnetic field embedded into a turbulent conducting medium grows exponentially while its characteristic scale decays. In the ISM and protogalactic plasmas, the magnetic Pr is very large, so a broad spectrum of growing…

Astrophysics · Physics 2008-11-26 Alexander Schekochihin , Steven Cowley , Jason Maron , Leonid Malyshkin

We present a detailed study of the complex ionization structure in a small (~250 pc) extended narrow line region (ENLR) cloud near Centaurus A using the Multi Unit Spectroscopic Explorer. This cloud is located in the so-called outer…

Astrophysics of Galaxies · Physics 2016-05-04 F. Santoro , J. B. R. Oonk , R. Morganti , T. A. Oosterloo , C. Tadhunter

It is now well established that the quiet Sun contains in total more magnetic flux than active regions and represents an important reservoir of magnetic energy. But the nature and evolution of these fields remain largely unknown. We…

Solar and Stellar Astrophysics · Physics 2021-07-07 Marianne Faurobert , Gilbert Ricort

We investigate the emergence of magnetic flux in the quiet Sun at very small spatial scales, focusing on the magnetic connection between the photosphere and chromosphere. The observational data consist of spectropolarimetric measurements…

Solar and Stellar Astrophysics · Physics 2009-07-22 M. J. Martinez Gonzalez , L. R. Bellot Rubio

Recent observations with the HINODE satellite have found abundant horizontal magnetic fields in the internetwork quiet Sun. We compare the results on the horizontal fields with ground-based observations. We obtained 30 sec-integrated data…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. A. R. Beck , R. Rezaei

Time-averaged series of granulation images are analysed using COLIBRI, a purpose-adapted version of a code originally developed to detect straight or curvilinear features in aerospace images. The algorithm of image processing utilises a…

Astrophysics · Physics 2008-04-19 A. V. Getling , A. A. Buchnev

A dense forest of slender bright fibrils near a small solar active region is seen in high-quality narrowband Ca II H images from the SuFI instrument onboard the Sunrise balloon-borne solar observatory. The orientation of these slender Ca II…

Stellar sources of gamma rays are one of the front lines in modern astrophysics whose understanding can benefit from observational tools not originally designed for their study. We take advantage of the high precision photometric…

High Energy Astrophysical Phenomena · Physics 2022-06-08 Enrique Mestre , Estrella Sánchez-Ayaso , Pedro L. Luque-Escamilla , Josep Martí , Josep M. Paredes , Daniel del Ser , Jorge Núñez

The origin and configuration of the gas which emits broad lines in Type I active galactic nuclei is not established yet. The lack of small-scale structure in the broad emission-line profiles is consistent with a smooth gas flow, or a…

Astrophysics · Physics 2009-11-13 Ari Laor , Aaron J. Barth , Luis C. Ho , Alexei V. Filippenko

Instabilities at interface of two stream granular flows have been reported in recent experiment [1] that breaking waves can form at the interface between two streams of identical grains flowing on an inclined plane downstream of a splitter…

Classical Physics · Physics 2007-05-23 Hua-Shu Dou , Boo Cheong Khoo , Nhan Phan-Thien

The Sun is a non-equilibrium dissipative system subjected to an energy flow which originates in its core. Convective overshooting motions create temperature and velocity structures which show a temporal and spatial evolution. As a result,…

Solar and Stellar Astrophysics · Physics 2015-06-11 F. Berrilli , S. Scardigli , S. Giordano

We determine the number density and area contribution of small-scale inter-granular calcium-II bright G-band structures in images of the quiet Sun as tracers of kilo-Gauss magnetic flux-concentrations. In a 149" x 117" G-band image of the…

Solar and Stellar Astrophysics · Physics 2012-10-23 Burkart Bovelet , Eberhard Wiehr

Here we report evidence of a large solar filament eruption on 2013, September 29. This smooth eruption, which passed without any previous flare, formed after a two-ribbon flare and a coronal mass ejection towards Earth. The coronal mass…

Solar and Stellar Astrophysics · Physics 2015-10-29 J. Palacios , C. Cid , A. Guerrero , E. Saiz , Y. Cerrato

We used multi-wavelength high-resolution data from ARIES, THEMIS, and SDO instruments, to analyze a non-standard, C3.3 class flare produced within the active region NOAA 11589 on 2012 October 16. Magnetic flux emergence and cancellation…

Solar and Stellar Astrophysics · Physics 2016-02-22 K. Dalmasse , R. Chandra , B. Schmieder , G. Aulanier