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Related papers: Oscillations in active region fan loops: Observati…

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Propagating disturbances are often observed in active region fan-like coronal loops. They were thought to be due to slow mode MHD waves based on some of the observed properties. But the recent studies involving spectroscopy indicate that…

Solar and Stellar Astrophysics · Physics 2015-11-11 S. Mandal , T. Samanta , D. Banerjee , S. Krishna Prasad , L. Teriaca

A comprehensive study of the physical parameters of active region fan loops is presented using the observations recorded with the Interface Region Imaging Spectrometer (IRIS), the EUV Imaging Spectrometer (EIS) on-board Hinode and the…

Solar and Stellar Astrophysics · Physics 2017-02-08 Avyarthana Ghosh , Durgesh Tripathi , G. R. Gupta , Vanessa Polito , Helen E. Mason , Sami K. Solanki

We report the first observation of multiple-periodic propagating disturbances along a fan-like coronal structure simultaneously detected in both intensity and Doppler shift in the Fe XII 195 A line with the EUV Imaging Spectrometer (EIS)…

Solar and Stellar Astrophysics · Physics 2010-11-11 T. J. Wang , L. Ofman , J. M. Davila , J. T. Mariska

Low-amplitude Doppler-shift oscillations have been observed in coronal emission lines in a number of active regions with the EUV Imaging Spectrometer (EIS) on the Hinode satellite. Both standing and propagating waves have been detected and…

Solar and Stellar Astrophysics · Physics 2015-05-18 John T. Mariska , K. Muglach

We present the first Hinode/EIS observations of 5 min quasi-periodic oscillations detected in a transition-region line (He II) and five coronal lines (Fe X, Fe XII, Fe XIII, Fe XIV, and Fe XV) at the footpoint of a coronal loop. The…

Solar and Stellar Astrophysics · Physics 2010-11-11 T. J. Wang , L. Ofman , J. M. Davila

We perform multiwavelength time-distance analysis of a fan loop system anchored in an isolated sunspot region AR 12553. The active region was observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. We measure…

Solar and Stellar Astrophysics · Physics 2020-07-01 Aishawnnya Sharma , Durgesh Tripathi , Robertus Erdelyi , G. R. Gupta , G. A. Ahmed

Recent observations from the Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode have shown that low density areas on the periphery of active regions are characterized by strong blue-shifts at 1 MK. These Doppler shifts have been…

Solar and Stellar Astrophysics · Physics 2015-05-19 Ignacio Ugarte-Urra , Harry P. Warren

We studied waves seen during the class C1.9 flare that occurred in Active Region NOAA 11272 on SOL2011-08-17. We found standing waves with periods in the 9- and 19-minute band in six extreme ultraviolet (EUV) wavelengths of the SDO/AIA…

Solar and Stellar Astrophysics · Physics 2016-11-29 S. M. Conde Cuellar , J. E. R. Costa , C. E. Cedeño Montaña

We observe intensity oscillations along coronal fan loops associated with the active region AR 11428. The intensity oscillations were triggered by blast waves which were generated due to X-class flares in the distant active region AR 11429.…

Solar and Stellar Astrophysics · Physics 2017-09-20 V. Pant , A. Tiwari , D. Yuan , D. Banerjee

Propagating slow magneto-acoustic waves are commonly observed in different coronal structures but are most prominent in active region fan loops. Their rapid damping with damping lengths of the order of a wavelength has been investigated in…

Solar and Stellar Astrophysics · Physics 2025-06-09 Suraj K. Tripathy , S. Krishna Prasad , D. Banerjee

In order to better understand the possibility of coronal heating by MHD waves, we analyze Fe xii 195.12{\AA} data observed with EUV Imaging Spectrometer (EIS) onboard Hinode. We performed a Fourier analysis of EUV intensity and Doppler…

Solar and Stellar Astrophysics · Physics 2015-05-19 Naomasa Kitagawa , Takaaki Yokoyama , Shinsuke Imada , Hirohisa Hara

Longitudinal intensity oscillations along coronal loops that are interpreted as signatures of magneto-acoustic waves are observed frequently in different coronal structures. The aim of this paper is to estimate the physical parameters of…

Solar and Stellar Astrophysics · Physics 2016-04-13 A. Abedini

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…

Solar and Stellar Astrophysics · Physics 2017-11-15 Dong Li , Zongjun Ning , Yu Huang , N. -H. Chen , Qingmin Zhang , Yingna Su , Wei Su

The velocity pattern of a fan loop structure within a solar active region over the temperature range 0.15-1.5 MK is derived using data from the EUV Imaging Spectrometer (EIS) on board the Hinode satellite. The loop is aligned towards the…

Solar and Stellar Astrophysics · Physics 2015-05-28 P. R. Young , B. O'Dwyer , H. E. Mason

Using data obtained by the EUV Imaging Spectrometer (EIS) onboard Hinode, we have per- formed a survey of obvious and persistent (without significant damping) Doppler shift oscillations in the corona. We have found mainly two types of…

Solar and Stellar Astrophysics · Physics 2012-10-31 Hui Tian , Scott W. McIntosh , Tongjiang Wang , Leon Ofman , Bart De Pontieu , Davina E. Innes , Hardi Peter

We report high resolution observations from the SDO/AIA of intensity oscillations in a hot, T~8-10 MK, loop. The AIA images show a large coronal loop that was rapidly heated following plasma ejection from one of the loop's footpoints. A…

Solar and Stellar Astrophysics · Physics 2014-09-16 Pankaj Kumar , D. E. Innes , B. Inhester

In this study we combine the multiwavelength ultraviolet -- optical (Solar Dynamics Observatory, SDO) and radio (Nobeyama Radioheliograph, NoRH) observations to get further insight into space-frequency distribution of oscillations at…

Solar and Stellar Astrophysics · Physics 2015-05-13 D. Y. Kolobov , N. I. Kobanov , A. A. Chelpanov , A. A. Kochanov , S. A. Anfinogentov , S. A. Chupin , I. I. Myshyakov , V. E. Tomin

Previous solar observations have shown that coronal loops near 1 MK are difficult to reconcile with simple heating models. These loops have lifetimes that are long relative to a radiative cooling time, suggesting quasi-steady heating. The…

We report decaying quasi-periodic intensity oscillations in the X-ray (6-12 keV) and extreme ultraviolet (EUV) channels (131, 94, 1600, 304 \AA) observed by the Fermi GBM (Gamma-ray Burst Monitor) and SDO/AIA, respectively, during a C-class…

Solar and Stellar Astrophysics · Physics 2015-06-24 Pankaj Kumar , Valery M. Nakariakov , Kyung-Suk Cho

Decayless kink oscillations, characterized by their lack of decay in amplitude, have been detected in coronal loops of varying scales in active regions, quiet Sun and coronal holes. Short-period (< 50 s) decayless oscillations have been…

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