Scientists have proposed a new way to create full maps of the distribution of the magnetic field in the solar corona according watching the sun polarimeter. Researchers have built a connection between the readings of this device and the parameters of the plasma processes in the solar corona. Of the latter, in turn, physicists have managed to obtain values of magnetic field strength, which was comparable to previously implemented spot measurements and the predictions of theoretical models. Article published in the journal Science.
The solar atmosphere is formed largely by a magnetic field in it, because it is full of the plasma of a suspension of charged particles, the behavior of which depends directly on the electromagnetic conditions at the point of its location. While each of the others the Sun of the layers is very closely linked with its neighbours, therefore, to understand physics of the processes taking place there, scientists need to be aware of the values of the magnetic field throughout the atmosphere of the star. However, until now researchers had no way of regularly and with good accuracy to measure magnetic field in the solar corona — the outer and the longest part of the atmosphere of the star.
For measurements of the magnetic field on the solar surface is commonly used Zeeman effect — the phenomenon of splitting of spectral lines of an atom in an external magnetic field. But for the crown, this method is not suitable, since the average field here is significantly less than those that can be registered on the surface of the disc. To be more precise, such measurements may be carried out only for small areas of the solar corona, which for some reason was a sharp increase in the magnetic field, however, to monitor the status of all of the crown it is not applicable. The problem of smallness of the magnitude of the magnetic field of the corona encountered and attempts to measure it using the measurement in the radio, observations of oscillating structures in the corona, and even research for these purposes, solar pulsation.
Czhao Yang (Yang Zihao) from Peking University and his colleagues found a way for one to two hours to take measurements for making a complete map of the magnetic field of the solar corona. This was made possible thanks to a new method of data analysis that scientists were obtained by observing the solar corona multi-functional polarimeter. One pixel used by the authors of the instrument corresponded to the phase of the solar corona 7000 to 7000 kilometers, which for these measurements is considered sufficiently high resolution. From the intensity of forbidden spectral lines of iron length and 1074,7 1079,8 nanometers, the researchers obtained a value of the electron density. Indicator of the speed of the Doppler shift of these lines, in turn, physicists have learned about the value of the phase speed of the running for the crown albanowski waves — transverse perturbations occurring in the plasma and propagate along the magnetic field lines. Magnetic field scientists have calculated these two values obtained from observations of the polarimeter.