Related papers: High-resolution Observations of the Shock Wave Beh…
We study the dynamics of shock waves observed in the umbra of a sunspot using the spectroscopic observations from the Interface Region Imaging Spectrometer (IRIS). The presence of the shock significantly deforms the shape of the spectral…
We analyse sunspot oscillations using Interface Region Imaging Spectrograph (IRIS) slit-jaw and spectral data and narrow-band chromospheric images from the New Solar Telescope (NST) for the main sunspot in NOAA AR 11836. We report that the…
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…
High-resolution observations of the solar chromosphere and transition region often reveal surge-like oscillatory activities above sunspot light bridges. These oscillations are often interpreted as intermittent plasma jets produced by…
We report on observations of highly-varying Si IV 1402.77 line profiles observed with the Interface Region Imaging Spectrograph (IRIS) during the M-class flare from 2022 January 18 at an unprecedented 0.8 s cadence. Moment analysis of this…
We analyze spectra of a slipping flare kernel observed during the 2015 June 22 M6.5-class flare by the Interface Region Imaging Spectrograph (IRIS). During the impulsive and peak phases of the flare, loops exhibiting an apparent slipping…
The center-to-limb variations (CLV) of transition region line Gaussian fit parameters in solar plage are reported for the first time. The Si iv 1402.77 A line observed by Interface Region Imaging Spectrograph (IRIS) is used. The spectral…
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…
Super-sonic downflows have been observed in transition region spectra above numerous sunspots; however, little research has been conducted to date into how persistent these signatures are within sunspots on time-scales longer than a few…
We present observations of persistent oscillations of some bright features in the upper-chromosphere/transition-region above sunspots taken by IRIS SJ 1400 {\AA} and upward propagating quasi-periodic disturbances along coronal loops rooted…
In the present paper, we use Si IV 1393.755 \AA\ spectral line observed by the Interface Region Imaging Spectrograph (IRIS) in the quiet-Sun to determine physical nature of the solar transition region (TR) oscillations. We analyze the…
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…
To study motions and oscillations in the solar chromosphere and at the transition region (TR) level we analyze some extreme Doppler shifts observed off-limb with the Interface Region Imaging Spectrograph (IRIS). Raster scans and slit-jaw…
We study point-like explosive events (EE), characterized by emission in the far wings of spectral lines, in a quiet region near the South Pole, using Interface Region Imaging Spectrograph (IRIS) spectra at two slit positions, slit-jaw (SJ)…
Following Couvidat (2013), we analyze data from the Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA) instruments onboard the Solar Dynamics Observatory: Doppler velocity and continuum intensity at 6173 A as…
The Extreme ultraviolet Imaging Spectrometer (EIS) on board Hinode is the first solar telescope to obtain wide slit spectral images that can be used for detecting Doppler flows in transition region and coronal lines on the Sun and to relate…
We present a detailed investigation of the Doppler shift oscillations in a hot loop during an M7.1 flare on 2014 October 27 observed by the Interface Region Imaging Spectrograph. The periodic oscillations are observed in the Doppler shift…
We analyze the propagation of waves in sunspots from the photosphere to the chromosphere using time series of co-spatial Ca II H intensity spectra (including its line blends) and polarimetric spectra of Si I 10827 and the He I 10830…
We report on the first Interface Region Imaging Spectrograph (IRIS) study of cool transition region loops. This class of loops has received little attention in the literature. A cluster of such loops was observed on the solar disk in active…
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…