Why this matters:
- NASA’s Chandra X-Ray Observatory was essential to this research. The researcher would not have been able to see the X-rays coming from a black hole without this telescope.
- Astronomical research has real-world impacts on Earth. For example, supermassive black holes test Albert Einstein's theory of relativity which is used to help navigate with GPS satellites and communicate around the world.
- This research also helps explain our natural curiosity about how Earth came to exist.
A Michigan State University researcher saw X-rays coming from a black hole using the NASA Chandra X-Ray Observatory telescope.
“Every large galaxy has a supermassive black hole, but the exact nature of the relationship between the two is still mysterious,” said Stephen DiKerby, a physics and astronomy research associate in College of Natural Science. “After analyzing data [from the Chandra telescope], I had a chill, because I realized I was looking at the X-rays from a supermassive black hole flicker on and off.”
Black holes have a mystique, an aura. They are the unseen monsters in the universe, but scientists around the world do not shy away from these behemoths. They embrace them as laboratories for physics and astronomy research.
Supermassive black holes are objects with millions or billions of times the Sun’s mass crammed into such a small space that even light cannot escape. Material falling into the intense gravity of the black hole can heat up to extreme temperatures.
X-rays from the environment near supermassive black holes can be observed with telescopes, such as the Chandra X-ray Observatory that orbits the Earth.
DiKerby, who’s also a member of the IceCube Neutrino Observatory, and his collaborators including his supervisor, Shuo Zhang, examined 15 years of data collected by Chandra. Then, they pieced together a record of the X-ray light produced by a supermassive black hole in the Andromeda galaxy called M31 star or M31*.
Their research provides insight into the unique relationship between a galaxy and its black hole. This is critical to understanding how the universe developed over the past 14 billion years. The results of their analyses were recently published in The Astrophysics Journal.
It began with a line of neutrino breadcrumbs
The story does not begin with black holes but neutrinos — tiny, electrically neutral particles that zoom through space to Earth. DiKerby and his IceCube colleagues follow neutrinos like a trail of breadcrumbs through space to gain greater insight into how the most extreme systems in the universe function. Neutrinos may be produced by the environments near supermassive black holes like M31*.
“Chandra has such fine spatial resolution that it can pick apart the X-ray emission from M31* from three other X-ray sources that crowd around it in the core of Andromeda. It’s the only telescope that can do this,” DiKerby said. “We were able to reconstruct the image — zoom and enhance like in a cop TV show — to pick apart the emission to only measure the X-rays from M31*, not the other sources.”
Winking photons illuminate the black hole
They determined that M31* has been in an elevated state since 2006, when it ejected a dramatic X-ray flare. They also discovered M31* experienced another X-ray flare in 2013 before settling to the post-2006 state. This finding aligns with a recent discovery by IceCube that linked neutrino-related flares in another galaxy to its supermassive black hole. These results show how observations of nearby supermassive black holes can reveal likely time windows for neutrino emissions.
Their work used the precise positions of four X-ray sources deep in the core of the Andromeda galaxy — S1, SSS, N1, and P2 — to pinpoint the location of the supermassive black hole to P2.
DiKerby compares tracking the X-ray brightness of these objects to standing in one end zone and measuring the intensity of four flickering candles at the far end of a football stadium. With the power and resolution of the Chandra telescope, the team could differentiate the data to isolate each of the neighboring objects.
This work is only possible because of Chandra’s unique observational capabilities. Despite continuing to work well, the telescope is in peril of losing funding. A proposed next generation telescope, AXIS, is still in the early stages of development and would not be operational until the 2030s.
“If Chandra is turned off, the resource to do these fine resolution observations would go away forever,” said DiKerby. “Maintaining these capabilities and planning for the next generation of telescopes is vital.”
DiKerby hopes this paper motivates people to continue to analyze data from M31*. The Chandra telescope needs to be maintained while plans continue for future telescope development.
“I want us to keep watching the system, to keep watching these flares, and to continue to write the history of super massive black holes,” he said.
