An international team of astronomers has found a black hole in the Markarian 1018 galaxy, cracking the code behind the galaxy’s changing brightness throughout the decades.
Markarian 1018, located 555 million light-years away from Earth, was first discovered in the 1980s emitting little light. A few years after, it became categorized as a Seyfert type, a galaxy with very high brightness.
However, the astronomers found that the galaxy once again dimmed in 2015 using the European Southern Observatory’s Very Large Telescope along with the NASA/ESA Hubble Space Telescope and NASA’s Chandra X-ray Observatory.
“When we re-observed [Markarian 1018] last year we found that it had returned to this dimmer state that it was in when it was first observed in the 1980s,” said study lead author Rebecca McElroy, a Ph.D. student at the University of Sydney and the ARC Centre of Excellence for All-Sky Astrophysics.
McElroy said this decline in brightness was because the black hole was starved of fuel or accretion material. “It’s possible that this starvation is because the inflow of fuel is being disrupted,” Ms. McElroy said. “This could be because of interactions with a second supermassive black hole.”
McElroy said the findings provide new knowledge on active galaxies. Previously, active galaxies have been categorized into two static types: obscured and unobscured. However, Markarian 1018 challenged this classification.
“Future research on the galaxy will allow us to explore the exciting world of starving black holes and changing active galaxies in more detail,” Fellow at the European Southern Observatory, Bernd Husemann said.