Astronomers from Sweden managed to find an explanation for a recent mystery in the center of the Milky Way: the high levels of scandium seen last spring near a giant black hole of the galaxy turned out to be just an optical illusion.
Last spring, researchers reported the apparent presence of surprising and dramatically high levels of three different elements in red giant stars that are 3 light years away from the central black hole. Various possible explanations were presented: the result of the destruction of early stars that fell into a black hole, or fragments from the collision of neutron stars.
The new analysis allowed us to find a more logical and simple explanation for the high levels of scandium, vanadium and yttrium. It turns out that the spectral lines presented in spring actually became an optical illusion. Spectral lines are used to find out the chemical composition of a star, focusing on its light. These giants have exhausted most of the hydrogen fuel, so the temperature reaches only half the sun.
It turns out that the lower temperature indices of stars helped to create the optical illusion that occurs when measuring spectral lines. In particular, this means that electrons in elements behave differently at different temperatures, which can also be misleading in the calculation of spectral lines in stars. A Keck telescope on Mauna Kea (Hawaii) was used for the analysis. A comprehensive mapping of the central regions of the Milky Way is under way, exploring spectral lines in the light of various stars to find out their composition. The goal is to get an idea of the events that took place in the Milky Way, and to understand the process of the birth of galaxies.
The spectral lines for each element are recorded in a high-resolution spectrometer — an advanced camera that generates a rainbow of starlight. The researchers studied part of the spectrum from near-infrared radiation - the thermal rays of stars. IR light is able to penetrate dust, interfering with the line of sight of the center of the Milky Way, which is 25,000 light-years distant. The large-scale analysis has just begun, therefore, in the near future, we are waiting for an exact result.