A whirling picture encompasses a brilliant spiral galaxy referred to as MCG-01-24-014, which is positioned about 275 million light-years from Earth. Along with being a well-defined spiral galaxy, MCG-01-24-014 has an especially energetic core referred to as an lively galactic nucleus (AGN) and is categorized as a Kind-2 Seyfert galaxy. Seyfert galaxies, together with quasars, host one of the widespread subclasses of AGN. Whereas the exact categorization of AGNs is nuanced, Seyfert galaxies are typically comparatively close by and their central AGN doesn’t outshine its host, whereas quasars are very distant AGNs with unbelievable luminosities that outshine their host galaxies.
There are additional subclasses of each Seyfert galaxies and quasars. Within the case of Seyfert galaxies, the predominant subcategories are Kind-1 and Kind-2. Astronomers distinguish them by their spectra, the sample that outcomes when mild is cut up into its constituent wavelengths. The spectral traces that Kind-2 Seyfert galaxies emit are related to particular ‘forbidden’ emission traces. To know why emitted mild from a galaxy might be forbidden, it helps to grasp why spectra exist within the first place. Spectra look the way in which they do as a result of sure atoms and molecules soak up and emit mild at very particular wavelengths. The rationale for that is quantum physics: electrons (the tiny particles that orbit the nuclei of atoms and molecules) can solely exist at very particular energies, and subsequently electrons can solely lose or achieve very particular quantities of vitality. These very particular quantities of vitality correspond to the wavelengths of sunshine which might be absorbed or emitted.
Forbidden emission traces shouldn’t exist in keeping with sure guidelines of quantum physics. However quantum physics is complicated, and among the guidelines used to foretell it had been formulated underneath laboratory circumstances right here on Earth. Below these guidelines, this emission is ‘forbidden’ — so inconceivable that it is disregarded. However in house, within the midst of an extremely energetic galactic core, these assumptions do not maintain anymore, and the ‘forbidden’ mild will get an opportunity to shine out towards us.