相关论文: Solar transition region in the quiet Sun and activ…

The Sun is the only star that we can spatially resolve and it can be regarded as a fundamental plasma laboratory of astrophysics. The solar transition region (TR), the layer between the solar chromosphere and corona, plays an important role…

The hydrogen Lyman-alpha plays a dominant role in the radiative energy transport in the lower transition region, and is important for the stud- ies of transition-region structure as well as solar wind origin. We investigate the Ly-alpha…

We study the line profiles of a range of transition region (TR) emission lines observed in typical quiet Sun regions. In magnetic network regions, the Si IV 1402\AA{}, C IV 1548\AA{}, N V 1238\AA{}, O VI 1031\AA{}, and Ne VIII 770\AA{}…

We study the TR properties above sunspots and the surrounding plage regions, by analyzing several sunspot spectra obtained by SUMER in March 1999 and November 2006. We compare the SUMER spectra observed in the umbra, penumbra, plage, and…

The plasma contributing to emission from the Sun between the cool chromosphere ($\le 10^4$K) and hot corona ($\ge 10^6$K) has been subjected to many different interpretations. Here we look at the magnetic structure of this transition region…

Transition region (TR) loops are arcade-like features in the solar transition region, with temperatures roughly between $2\times10^4$ K and $6\times10^5$ K. They are a fundamental building block of TR, which are results of the coupling…

The brightness of the emission from coronal loops in the solar atmosphere is strongly dependent on the temperature and density of the confined plasma. After a release of energy, these loops undergo a heating and upflow phase, followed by a…

The solar chromosphere and transition region (TR) form an interface between the Sun's surface and its hot outer atmosphere. Here most of the non-thermal energy that powers the solar atmosphere is transformed into heat, although the detailed…

The solar transition region (TR) is a narrow interface between the chromosphere and corona, where emitted radiation contains critical information pertinent to coronal heating processes. We conducted 2-dimensional radiation…

There is a thin transition region (TR) in the solar atmosphere where the temperature rises from 10,000 K in the chromosphere to millions of degrees in the corona. Little is known about the mechanisms that dominate this enigmatic region…

The Enthalpy Based Thermal Evolution of Loops (EBTEL) approximate model for static and dynamic coronal loops is developed to include the effect of a loop cross-sectional area which increases from the base of the transition region (TR) to…

The measured average velocities in solar and stellar spectral lines formed at transition region temperatures have been difficult to interpret. However, realistic three-dimensional radiation magnetohydrodynamics (3D rMHD) models of the solar…

IRIS data allow us to study the solar transition region (TR) with an unprecedented spatial resolution of 0.33 arcsec. On 2013 August 30, we observed bursts of high Doppler shifts suggesting strong supersonic downflows of up to 200 km/s and…

Context. Emission lines formed in the transition region and corona show dominantly redshifts and blueshifts, respectively. Aims. We investigate the Doppler shifts in a 3D radiation MHD model of the quiet Sun and compare these to observed…

The transition region between the Sun's corona and chromosphere is important to the mass and energy transfer from the lower atmosphere to the corona; consequently, this region has been studied intensely with ultraviolet (UV) and extreme…

We examine the hypothesis that ``cool loops'' dominate emission from solar transition region plasma below temperatures of $2\times10^5$K. We compare published VAULT images of H L$\alpha$, a lower transition region line, with…

The origin of solar transition region redshifts is not completely understood. Current research is addressing this issue by investigating three-dimensional magneto-hydrodynamic models that extend from the photosphere to the corona. By…

Prompted by high resolution observations, I propose an explanation for the 40+ year old problem of structure and energy balance in the solar transition region. The ingredients are simply cross-field diffusion of neutral atoms from cool…

We performed a systematic study of the Doppler shifts and electron densities measured in an EUV bright point (hereafter BP) observed in more than 10 EUV lines with formation temperatures from log (T/K) p 4.5 to 6.3. Those parts of a BP seen…

The relationships among coronal loop structures at different temperatures is not settled. Previous studies have suggested that coronal loops in the core of an active region are not seen cooling through lower temperatures and therefore are…