The incredible first image of the shadow of a black hole published about two years ago. Now, researchers in collaboration with Event Horizon Telescope (EHT) have created it who has added new and important details to the historic picture. For the first time, they measured the magnetic field around the edge of a black hole. In two papers in The Astrophysical Journal Letters (here and here), astronomers have discovered a significant portion of the light around the galaxy M87’s supermassive black hole and described how they used light to study the magnetic field.
The observations help astronomers understand how phenomena like cosmic jets formed. Light is a wave that usually sinks in all directions. Polarized light waves are light waves whose vibrations occur in a single plane. Light becomes polarize as it passes through certain filters, such as sunglasses, but emitter when it is from magnetic fields in the warmer regions of space.
Polarized light has many technical applications, for example, when you watch a 3D movie; you wear glasses with polarized lenses so that the right eye and the left eye actually see different images that our brain interprets as three-dimensional. The basic idea is that light made up of electromagnetic waves, and if we look at a cross-section of these waves, oscillations can occur in each oscillation. However, when light is polarized, it only fluctuates in a certain direction. In nature, interactions between light and matter can affect this aspect, and magnetic fields are one of these interactions. Studying polarization is not easy but it is extremely important.
Explained Dr Iván Martí-Vidal, one the coordinators of the EHT Polarimetry Working Group, in a statement, “This work is a major milestone: the polarization of light carries information that allows us to better understand the physics behind the image we saw in April 2019, which was not possible before.” “[U] The launch of this new polarized-light image requires years of work due to the complex techniques involved in data acquisition and analysis.” Polarized light like sunglasses helps to reduce glare from bright light sources. This allows researchers to keep a sharp view of the interior of the black hole and to map the lines of the magnetic field present there.