Hubble Telescope Captures Striking Image of a Galaxy with ‘Forbidden’ Light

Image: Hubble Space Telescope Discovers a Galaxy with Unusual Light Emission

The NASA Hubble Space Telescope has captured a stunning image of a spiral galaxy known as MCG-01-24-014, located approximately 275 million light-years away from Earth. This galaxy is not only a well-defined spiral, but it also possesses an energetic core classified as an active galactic nucleus (AGN) and is categorized as a Type-2 Seyfert galaxy.

Seyfert galaxies, along with quasars, are subclasses of AGN. While the specific categorization of AGNs can be complex, Seyfert galaxies tend to be relatively nearby, and their central AGN does not outshine its host. In contrast, quasars are extremely distant AGNs with incredible luminosities that outshine their host galaxies.

Within the realm of Seyfert galaxies, there are two predominant subcategories: Type-1 and Type-2. Astronomers differentiate between these types based on their spectra, which represent the pattern that results when light is split into its constituent wavelengths. The spectral lines emitted by Type-2 Seyfert galaxies are associated with specific ‘forbidden’ emission lines.

To understand why emitted light from a galaxy could be considered ‘forbidden,’ it is essential to grasp the concept of spectra. Spectra occur because certain atoms and molecules absorb and emit light at very specific wavelengths. This phenomenon is due to quantum physics, where electrons in atoms and molecules can only exist at specific energies. Consequently, electrons can only lose or gain specific amounts of energy, which correspond to the wavelengths of light that are absorbed or emitted.

In the case of ‘forbidden’ emission lines, these lines should not exist according to certain rules of quantum physics. These rules were formulated under laboratory conditions on Earth and predict that the emission is highly improbable. However, in the unique environment of a highly energetic galactic core, such as the one found in MCG-01-24-014, these assumptions no longer hold true. In these extreme conditions, the ‘forbidden’ light has a chance to shine out towards us.

This discovery highlights the fascinating and complex nature of the universe and the ongoing exploration of celestial bodies through advanced telescopic technology like the Hubble Space Telescope.