Search Publications
The centre-to-limb variation of non-thermal velocities using IRIS Si IV
Del Zanna, Giulio; Rao, Yamini K.; Mason, Helen E.
We study the non-thermal velocities in the quiet Sun using various high spatial, temporal, and spectral resolution observations from the Interface Region Imaging Spectrograph (IRIS). We focus our analysis on the transition region using the optically thin line (Si IV 1393.7 Å), and select line profiles that are nearly Gaussian. We find evidence of …
Characteristics of chromospheric oscillation periods in magnetic bright points
Tavabi, Ehsan; Sadeghi, Rayhane
In this investigation, oscillation periods in Mg II k-line intensity, brightness temperature, and Doppler velocity obtained above magnetic bright points (MBPs) are investigated. For this purpose, data from the Interface Region Imaging Spectrometer (IRIS) observing the higher chromosphere and transition region (TR) were analysed, together with imag…
Path-lengths in the quiet Sun transition region using O IV lines from IRIS
Del Zanna, Giulio; Rao, Yamini K.; Mason, Helen E. +1 more
We use spectroscopic diagnostics to determine different plasma parameters in the transition region of the quiet Sun. The electron number density from O IV lines using high-resolution spectral observations from the Interface Region Imaging Spectrograph (IRIS) are estimated to be around 1010 cm-3, in agreement with literature v…
Spectroscopic and imaging observations of transient hot and cool loops by IRIS and SDO
Gupta, Girjesh R.; Nayak, Sushree S.
Coronal loops are the basic building blocks of the solar atmosphere and are observed on various length scales. However, their formation mechanism is still unclear. In this paper, we present spectroscopic and imaging observations of small-scale transients and the subsequent formation of transient loops. For this purpose, we have utilized the multiw…
Detection of spicules termed rapid blueshifted excursions as seen in the chromosphere via H α and the transition region via Si IV 1394 Å line emission
Shetye, Juie; Doyle, J. Gerry; Vilangot Nhalil, Nived
We show signatures of spicules termed rapid blueshifted excursions (RBEs) in the Si IV 1394 Å emission line using a semi-automated detection approach. We use the H α filtergrams obtained by the CRISP imaging spectropolarimeter on the Swedish 1-m Solar Telescope and co-aligned Interface Region Imaging Spectrograph data using the SJI 1400 Å channel …
Spectroscopic study of solar transition region oscillations in the quiet-Sun observed by IRIS using the Si IV spectral line
Srivastava, A. K.; Wang, T. J.; Kayshap, P. +3 more
In this paper, we use the Si IV 1393.755 Å spectral line observed by the Interface Region Imaging Spectrograph (IRIS) in the quiet-Sun (QS) to determine the physical nature of the solar transition region (TR) oscillations. We analyse the properties of these oscillations using wavelet tools (e.g. power, cross-power, coherence, and phase difference)…