Influence of the Magnetic Field on Oscillation Spectra in Solar Faculae

Abstract

In this work, we studied oscillation parameters in faculae above magnetic knots and in the adjacent to them areas. Using SDO data we analysed oscillations in magnetic strength, Doppler velocity, and intensity signals for the lower photosphere, and in intensity for the higher levels. We found that in the magnetic field strength oscillation spectra in magnetic knots, peaks at a frequency of about 4.8 mHz appear, while there are no such frequencies in the adjacent facular patches of a moderate field strength. On the contrary, Doppler velocity photospheric oscillation spectra are similar for these types of regions: in both cases, the significant peaks are in the 2.5--4.5 mHz range, though the oscillations in magnetic knots are 2--3 times weaker than those at the facular periphery. At the upper photosphere, the dominant frequencies in magnetic knots are 0.5--1 mHz higher than in the medium-field regions. The transition region oscillations above magnetic knots mainly concentrate in the 3--6 mHz range, and those above moderate-field patches concentrate below 3 mHz.Comment: 16 pages, 9 figure

Comparing the main oscillation characteristics in the solar chromosphere and magnetosphere based on studies made in ISTP SB RAS

“…Oscillations in faculae Faculae feature five-minute oscillations in signals of LOS velocities both in the photosphere and in the chromosphere [Kobanov et al, 2013a], although the spatial distribution of the oscillations in faculae is inhomogeneous. In LOS velocity signals, frequencies are higher in regions of intense magnetic field (magnetic hills) and lower closer to the boundaries of faculae [Chelpanov et al, 2015;Chelpanov et al, 2016b]. Kobanov and Pulyaev [2007] have found signs of propagating waves above magnetic hills.…”

Quasi-periodic oscillations of small-scale magnetic structures and a specific method for measuring the differential rotation of the Sun

“…В работе показано, что стабильный p2p-артефакт, присущий данным матрицы SDO/HMI, в сочетании с фурье-анализом является эффективным средством для измерения скорости различных трассеров на Солнце. Солнечные пятна 14.37 2.60 0 Tang [1981] Магнитное поле 14.37 2.30 1.62 Snodgrass [1983] Спектроскопия 14.19 1.70 2.36 Howard et al [1983] Факелы 14.4 1.5 0 Adams, Tang [1977] x-координата 14.7 3.39 0 данная работа Магнитное поле 14.8 4.115 0 данная работа 3. Кривые дифференциального вращения, полученные по мелкомасштабным магнитным структурам с использованием p2p-эффекта на основе данных SDO/HMI, совпадают с кривыми, полученными ранее по наземным наблюдениям.…”

“…Исследование квазипериодических колебаний различных структур на Солнце в активных областях и вне их играет важную роль в изучении физических параметров солнечной атмосферы . Хорошо известны осцилляции Солнца с периодом 3-10 мин, которые можно интерпретировать как распространение МГД-волн вдоль магнитных трубок в активных солнечных образованиях Chelpanov et al, , 2016. Кроме того, колебания с периодами от 20-40 мин до десятков часов были обнаружены в спектрах мощности солнечных магнитных элементов: солнечных пятен, волокон и факелов [Efremov et al, 2010;Smirnova et al, 2013;Kolotkov et al, 2017].…”

Long quasi-periodic oscillations of the faculae and pores

“…Recently, magnetohydrodynamic (MHD) oscillations of magnetic knots in the faculae regions of the Sun and the brightness variability of faculae visible in the solar chromosphere have been investigated very intensively, (e.g. Chelpanov et al 2016;Kostik & Khomenko 2016). Bloomfield et al (2006) and Jess et al (2009) considered the physical connection between the bright points at the level of the chromosphere and the small-scale magnetic structures (SSMSs) at the level of photosphere.…”