High-frequency coronal Alfvénic waves observed with DKIST/Cryo-NIRSP
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arXiv
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| Autores principales: | , , , |
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| Formato: | Preprint |
| Publicado: |
2025
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| _version_ | 1866909502312284160 |
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| author | Morton, Richard J. Molnar, Momchil Cranmer, Steven R. Schad, Thomas A. |
| author_facet | Morton, Richard J. Molnar, Momchil Cranmer, Steven R. Schad, Thomas A. |
| contents | The presence and nature of low-frequency (0.1-10~mHz) Alfvénic waves in the corona has been established over the last decade, with many of these results coming from coronagraphic observations of the infrared Fe XIII line. The Cryo-NIRSP instrument situated at DKIST has recently begun acquiring science quality data of the same Fe XIII line, with at least a factor of 9 improvement in spatial resolution, a factor 30 increase in temporal resolution and an increase in signal-to-noise, when compared to the majority of previously available data. Here we present an analysis of 1~s cadence sit-and-stare data from Cryo-NIRSP, examining the Doppler velocity fluctuations associated with the Fe XIII 1074~nm coronal line. We are able to confirm previous results of Alfvénic waves in the corona as well as explore a new frequency regime. The data reveals that the power law behaviour of the Doppler velocity power spectrum extends to higher frequencies. This result appears to challenge some models of photospheric-driven Alfvénic waves that predict a lack of high frequency wave power in the corona due to strong chromospheric damping. Moreover, the high-frequency waves do not transport as much energy as their low-frequency counterparts, with less time-averaged energy per frequency interval. We are also able to confirm the incompressible nature of the fluctuations with little coherence between the line amplitude and Doppler velocity time-series. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2501_03758 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | High-frequency coronal Alfvénic waves observed with DKIST/Cryo-NIRSP Morton, Richard J. Molnar, Momchil Cranmer, Steven R. Schad, Thomas A. Solar and Stellar Astrophysics The presence and nature of low-frequency (0.1-10~mHz) Alfvénic waves in the corona has been established over the last decade, with many of these results coming from coronagraphic observations of the infrared Fe XIII line. The Cryo-NIRSP instrument situated at DKIST has recently begun acquiring science quality data of the same Fe XIII line, with at least a factor of 9 improvement in spatial resolution, a factor 30 increase in temporal resolution and an increase in signal-to-noise, when compared to the majority of previously available data. Here we present an analysis of 1~s cadence sit-and-stare data from Cryo-NIRSP, examining the Doppler velocity fluctuations associated with the Fe XIII 1074~nm coronal line. We are able to confirm previous results of Alfvénic waves in the corona as well as explore a new frequency regime. The data reveals that the power law behaviour of the Doppler velocity power spectrum extends to higher frequencies. This result appears to challenge some models of photospheric-driven Alfvénic waves that predict a lack of high frequency wave power in the corona due to strong chromospheric damping. Moreover, the high-frequency waves do not transport as much energy as their low-frequency counterparts, with less time-averaged energy per frequency interval. We are also able to confirm the incompressible nature of the fluctuations with little coherence between the line amplitude and Doppler velocity time-series. |
| title | High-frequency coronal Alfvénic waves observed with DKIST/Cryo-NIRSP |
| topic | Solar and Stellar Astrophysics |
| url | https://arxiv.org/abs/2501.03758 |