Astrophysicists have been investigating galactic radio objects that adopt shapes, such as Christmas trees and harps.
Researchers at the Leibniz Institute for Astrophysics in Potsdam (AIP) and the Max Planck Institute for Astrophysics in Garching (MPA) have been investigating galactic radio objects that adopt shapes, such as Christmas trees and harps.
The inner region of our Milky Way galaxy is characterised by large amounts of warm gases, cosmic rays and radio emissions. Timon Thomas from the AIP, the leading author of the study, commented: “Astronomers have been observing planar radio-emitting magnetised structures in the galactic centre for almost twenty years.
“Recent observations with the MeerKAT telescope in South Africa show that these are organised into groups of almost parallel filaments, that span over a length of several light years,
“The filaments are seemingly sorted by their length, so that they look like the strings of a harp.” Therefore, the researcher team from Potsdam and Garching called these objects radio synchrotron harps. Synchrotron is the name of the mechanism that generates the radio emission. It occurs when charged particles like electrons are accelerated in magnetic fields.
“The observed structures are created when massive stars or pulsars fly through an ordered magnetic field and discharge cosmic ray particles along their path into these magnetic fields,” explains co-author Christoph Pfrommer from AIP.
Pfrommer continued: “The particles propagate along the magnetic field lines, usually transverse to the stellar orbit, causing the magnetic fields in the radio regime to light up and appear like the strings of a harp.”
The exact transport process of the particles along this string is currently eluding scientists. The astrophysics from this study assume that the individual strings show a chronological sequence in which the particles have spread along the magnetic field lines from their point of release.
If this propagation was a diffusion process, the structures seen in the radio observations should have rounded bell shapes, however, they do not.