Abstract Details

Name: Nancy Narang
Affiliation: IIA, Bengaluru
Conference ID: ASI2019_40
Title : High-Frequency Dynamics of an active region moss as observed by IRIS
Authors and Co-Authors : Nancy Narang, Vaibhav Pant, Tom Van Doorsselaere, Dipankar Banerjee
Abstract Type : Oral
Abstract Category : Sun and the Solar System
Abstract : The high temporal, spatial and spectral resolution of IRIS has provided a new insight into the understanding of different small-scale processes occurring at the chromospheric and transition region heights. We study the dynamics of high-frequency oscillations of an active region (AR 2376) moss as recorded by simultaneous imaging and spectral data of IRIS. Power maps generated from slit-jaw images in Si IV 1400 Å passband and sit-and-stare spectroscopic observations of Si IV 1403 Å spectral line reveal the presence of high-frequency oscillations with 1-2 minutes periods. The presence of such low periodicities is further confirmed by intrinsic mode functions (IMFs) as obtained by empirical mode decomposition (EMD) technique. We find the high-frequency oscillations possess significant power in the small localized regions within the bright moss, which indicates finer structuring in the active regions moss. These high-frequency oscillations could be due to the presence of magnetohydrodynamic (MHD) waves, or quasi-periodic flows, or a combination of both and can be reasonable candidates for coronal heating.