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Related papers: Velocities measured in small scale solar magnetic …

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We explore the general properties of near-surface flows around solar active regions. Helioseismic holography is applied to HMI Dopplergrams yielding nearly 5000 flow measurements of 336 unique active regions observed by the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2019-03-20 D. C. Braun

The velocity pattern of a fan loop structure within a solar active region over the temperature range 0.15-1.5 MK is derived using data from the EUV Imaging Spectrometer (EIS) on board the Hinode satellite. The loop is aligned towards the…

Solar and Stellar Astrophysics · Physics 2015-05-28 P. R. Young , B. O'Dwyer , H. E. Mason

The physical conditions leading the sunspot penumbra decay are poorly understood so far. We investigate the photospheric magnetic and velocity properties of a sunspot penumbra during the decay phase to advance the current knowledge of the…

Solar and Stellar Astrophysics · Physics 2021-09-15 M. Murabito , S. L. Guglielmino , I. Ermolli , P. Romano , S. Jafarzadeh , L. H. M. Rouppe van der Voort

We gave an extensive study for the quasi-periodic perturbations on the time profiles of the line of sight (LOS) magnetic field in 10x10 sub-areas in a solar plage region (corresponds to a facula on the photosphere). The perturbations are…

Solar and Stellar Astrophysics · Physics 2022-04-20 Haisheng Ji , Parida Hashim , Zhenxiang Hong , Zhe Xu , Jinhua Shen , Kaifan Ji , Wenda Cao

We characterize waves in small magnetic elements and investigate their propagation in the lower solar atmosphere from observations at high spatial and temporal resolution. We use the wavelet transform to analyze oscillations of both…

Solar and Stellar Astrophysics · Physics 2017-03-31 Shahin Jafarzadeh , S. K. Solanki , M. Stangalini , O. Steiner , R. H. Cameron , S. Danilovic

We investigate the oscillatory properties of the quiet solar chromosphere in relation to the underlying photosphere, with particular regard to the effects of the magnetic topology. We perform a Fourier analysis on a sequence of…

Astrophysics · Physics 2007-05-23 A. Vecchio , G. Cauzzi , K. P. Reardon , K. Janssen , T. Rimmele

The flows in and around sunspots are rich in detail. Starting with the Evershed flow along low-lying flow channels, which are cospatial with the horizontal penumbral magnetic fields, Evershed clouds may continue this motion at the periphery…

Solar and Stellar Astrophysics · Physics 2015-05-19 Carsten Denker , Meetu Verma

Convective flows are known as the prime means of transporting magnetic fields on the solar surface. Thus, small magnetic structures are good tracers of the turbulent flows. We study the migration and dispersal of magnetic bright features…

Using data from the Michelson Doppler Imager (MDI) instrument on board the Solar and Heliospheric Observatory (SOHO), we study the large-scale velocity fields in the outer part of the solar convection zone using the ring diagram technique.…

Astrophysics · Physics 2015-06-24 Sarbani Basu , H. M. Antia

Filaments/prominences are cold plasma (~ 10000 K) embedded in the solar corona, two orders of magnitude hotter. Filament plasma is structured by the magnetic field in thin elongated threads. Counter-streaming flows have been observed. The…

Solar and Stellar Astrophysics · Physics 2025-06-24 Garima Karki , Brigitte Schmieder , Pascal Demoulin , Pooja Devi , Ramesh Chandra , Reetika Joshi

We measure the horizontal subsurface flow in a fast emerging active region (NOAA 11158) using the ring-diagram technique and the HMI high-spatial resolution Dopplergrams. This active region had a complex magnetic structure and displayed…

Solar and Stellar Astrophysics · Physics 2015-08-04 Kiran Jain , S. C. Tripathy , F. Hill

Multi-wavelength observations of an M 2.0 flare event on 2000 March 23 in NOAA active region 8910 provide us a good chance to study the detailed structure and dynamics of the magnetic reconnection region. In the process of the flare,…

Solar and Stellar Astrophysics · Physics 2015-05-13 Leping Li , Jun Zhang

We propose a useful method for mapping large-scale velocity fields in the solar photosphere. It is based on the local correlation tracking algorithm when tracing supergranules in full-disc dopplergrams. The method was developed using…

Astrophysics · Physics 2007-05-23 M. Svanda , M. Klvana , M. Sobotka

We search for velocity changes (i.e., acceleration/deceleration) of narrow absorption lines (NALs) that are intrinsic to the quasars, using spectra of 6 bright quasars that have been observed more than once with 8-10m class telescopes.…

Astrophysics of Galaxies · Physics 2019-01-16 Toru Misawa , Michael Eracleous , Jane C. Charlton , Nobunari Kashikawa

We investigate the plasma flow properties inside a Supergranular (SG) cell, in particular its interaction with small scale magnetic field structures. The SG cell has been identified using the magnetic network (CaII wing brightness) as…

Astrophysics · Physics 2009-11-13 Dario Del Moro , Silvia Giordano , Francesco Berrilli

Simultaneous measurement of line-of-sight (LOS) magnetic and velocity fields at the photosphere and chromosphere are presented. Fe I line at $\lambda6569$ and $H_{\alpha}$ at $\lambda6563$ are used respectively for deriving the physical…

Astrophysics · Physics 2009-11-13 K. Nagaraju , K. Sankarasubramanian , K. E. Rangarajan

The Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) is designed to study oscillations and the mag- netic field in the solar photosphere. It observes the full solar disk in the Fe I absorption line at…

Solar and Stellar Astrophysics · Physics 2015-05-28 Bernhard Fleck , Sebastien Couvidat , Thomas Straus

We study the properties of solar magnetic fields on scales less than the spatial resolution of solar telescopes. A synthetic infrared spectropolarimetric diagnostics based on a 2D MHD simulation of magnetoconvection is used for this. We…

Solar and Stellar Astrophysics · Physics 2009-02-10 V. A. Sheminova

Using data from orbits one to eleven of the Parker Solar Probe (PSP) mission, the magnetic field spectral index was measured across a range of heliocentric distances. The previously observed transition between a value of $-5/3$ far from the…

Solar and Stellar Astrophysics · Physics 2023-07-11 J. R. McIntyre , C. H. K. Chen , A. Larosa

We present in this Letter the first coordinated radio occultation measurements and ultraviolet observations of the inner corona below 5.5 Rs, obtained during the Galileo solar conjunction in January 1997, to establish the origin of the slow…

Astrophysics · Physics 2009-10-30 S. R. Habbal , R. Woo , S. Fineschi , R. O'Neal , J. Kohl , G. Noci , C. Korendyke