Signatures of red-shifted footpoints in the quiescent coronal loop system. (arXiv:1908.02865v1 [astro-ph.SR])

Signatures of red-shifted footpoints in the quiescent coronal loop system. (arXiv:1908.02865v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Rao_Y/0/1/0/all/0/1">Yamini K. Rao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Srivastava_A/0/1/0/all/0/1">Abhishek K. Srivastava</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kayshap_P/0/1/0/all/0/1">Pradeep Kayshap</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dwivedi_B/0/1/0/all/0/1">Bhola N. Dwivedi</a>

We observed quiescent coronal loops using multi-wavelength observations from
the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory
(SDO) on 2016 April 13. The flows at the footpoints of such loop systems are
studied using spectral data from Interface Region Imaging Spectrograph (IRIS).
The Doppler velocity distributions at the footpoints lying in the moss region
show the negligible or small flows at Ni I, Mg II k3 and C II line
corresponding to upper photospheric and chromospheric emissions. Significant
red-shifts (downflows) ranging from (1 to 7) km/s are observed at Si IV
(1393.78 A; log(T/K) = 4.8) which is found to be consistent with the existing
results regarding dynamical loop systems and moss regions. Such downflows agree
well with the impulsive heating mechanism reported earlier.

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