The mystery that has tormented the minds of astronomers for many years is finally solved. A new study on the Markarian galaxy 1018 has revealed why this distant galaxy has been getting brighter and dimmer over 30 years.
The Markarian Galaxy 1018 is an 'active galaxy' with an extremely bright core (active galactic nucleus). It is believed that even if these nuclei occupy a relatively small fraction of space, the light from some of them can outshine the light from all the stars in the galaxy. Supermassive black holes are located at the center of many active galaxies. As material falls into these black holes, it accelerates and begins to emit light. In the event that the black hole does not receive enough material, the core is darkened.
What is happening with the Markarian galaxy 1018 is described in detail at once in two new research papers published in the Astronomy & Astrophysics Journal in September 2016. The studies were carried out on the basis of data from several telescopes and observatories at once.
It turned out that Markarian 1018 differs from most other active galaxies, as it changed its type in astronomical terms in the 'blink of an eye'. The galaxy transitioned from a dim to a bright stage in the 1980s, and between 2010 and 2016, the luminosity level dropped eightfold.
The researchers studied two hypotheses according to which the core could tarnish over time. Either it is surrounded by gas and dust, or the black hole in the center of the galaxy is not receiving enough material, figuratively speaking, 'starving'.
After analyzing data from three different telescopes at once (Hubble, Galaxy Evolution Explorer, and Sloan Digital Sky), scientists came to a completely unambiguous answer – Markarian 1018 is dimming, as the black hole in its center lacks material and is on a long-term 'diet'.
