相关论文: Absolute velocity measurements in sunspot umbrae

The decay of sunspot plays a key role in magnetic flux transportation in solar active regions (ARs). To better understand the physical mechanism of the entire decay process of a sunspot, an {\alpha}-configuration sunspot in AR NOAA 12411…

The high spatial and time resolution data obtained with SDO/AIA for the sunspot in active region NOAA 11131 on 08 December 2010 were analysed with the time-distance plot technique and the pixelised wavelet filtering method. Oscillations in…

Solar active regions show a wide variety of oscillatory phenomena. The presence of the magnetic field leads to the appearance of several wave modes, whose behavior is determined by the sunspot thermal and magnetic structure. We aim to study…

Context. The carbon monoxide (CO) molecular line at around 46655 A in solar infrared spectra is often used to investigate the dynamic behavior of the cold heart of the solar atmosphere, i.e., sunspot oscillation, especially at the sunspot…

With an aim to examine whether the predicted solar gravitational redshift can be observationally confirmed under the influence of the convective Doppler shift due to granular motions, we attempted measuring the absolute spectral line-shifts…

Delta ($\delta$) sunspots sometimes host fast photospheric flows along the central magnetic polarity inversion line (PIL). Here we study the strong Doppler shift signature in the central penumbral light bridge of solar active region NOAA…

Spatially averaged (> 50'') EUV spectral lines in the transition region of solar quiet regions are known to be redshifted. Because the mechanism underlying this phenomenon is unclear, we require additional physical information on the lower…

aims: We study the recently discovered twisting motion of bright penumbral filaments with the aim of constraining their geometry and the associated magnetic field. methods: A large sunspot located $40\degr$ from disk center was observed at…

Numerical simulations indicate that the filamentation of sunspot penumbrae and the associated systematic outflow (the Evershed effect) are due to convectively driven fluid motions constrained by the inclined magnetic field. We investigate…

Imaging systems based on a narrow-band tunable filter are used to obtain Doppler velocity maps of solar features. These velocity maps are created by taking the difference between the blue- and red-wing intensity images of a chosen spectral…

Within the umbrae of sunspots, convection is generally inhibited by the presence of strong vertical magnetic fields. However, convection is not completely suppressed in these regions: bright features, known as umbral dots, are probably…

The photospheric Evershed flow is normally oriented radially outward, yet sometimes opposite velocities are observed not only in the chromosphere but also in the photospheric layers of the penumbra. We study the velocity field in a special…

We discuss NICOLE inversions of Fe I 630.15 nm and 630.25 nm Stokes spectra from a sunspot penumbra recorded with the CRISP imaging spectropolarimeter on the Swedish 1-m Solar Telescope at a spatial resolution close to 0.15". We report on…

The dynamics of prominence fine structures is a challenge to understand the formation of cool plasma prominence embedded in the hot corona. Recent observations from the high resolution Hinode/SOT telescope allow us to compute velocities…

Umbral dots (UDs) were observed in a stable sunspot in NOAA 10944 by the Hinode Solar Optical Telescope on 2007 March 1. The observation program consisted of blue continuum images and spectropolarimetric profiles of Fe I 630 nm line. An…

High-resolution spectropolarimetric observations of active region NOAA 11271 were obtained with the spectro-polarimeter on board Hinode to analyze the properties of an anomalous flow in the photosphere in a sunspot penumbra. We detect a…

A light bridge is a prominent structure commonly observed within a sunspot. Its presence usually triggers a wealth of dynamics in a sunspot, and has a lasting impact on sunspot evolution. However, the fundamental structure of light bridges…

High cadence, multi-wavelength observations and simulations are employed for the analysis of solar photospheric magnetic bright points (MBPs) in the quiet Sun. The observations were obtained with the Rapid Oscillations in the Solar…

Sunspots are prominent manifestations of the solar cycle and provide key constraints for understanding its operation. Also, knowing internal structure of sunspots allows us to gain insights on the energy transport in strong magnetic fields…

The rotational Doppler effect, for which the frequency shift is proportional to the light's orbital angular momentum $\ell$ and the object's rotational speed ($\Delta f \propto\ell \Omega$), has proven to be a powerful tool for detecting…