Report
High-frequency coronal Alfv\'enic waves observed with DKIST/Cryo-NIRSP
| العنوان: | High-frequency coronal Alfv\'enic waves observed with DKIST/Cryo-NIRSP |
|---|---|
| المؤلفون: | Morton, Richard J., Molnar, Momchil, Cranmer, Steven R., Schad, Thomas A. |
| سنة النشر: | 2025 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | The presence and nature of low-frequency (0.1-10~mHz) Alfv\'enic 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 Alfv\'enic 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 Alfv\'enic 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. Comment: 20 pages, 8 figures, Submitted |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2501.03758 |
| رقم الانضمام: | edsarx.2501.03758 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |