This Is What Happens When A Supermassive Black Hole Swallows A Star
It's a once-in-a-lifetime experience. For the first time, astronomers were able to watch what happens when a black hole eats a star.
A Special Occasion
One of the effects: a powerful jetstream extending into one direction that was caught by radio and infrared telescopes.
"Never before have we been able to directly observe the formation and evolution of a jet from one of these events," Miguel Perez-Torres, a scientist from the Astrophysical Institute of Andalusia, says in a statement.
The paper, published in the journal Science on Thursday, June 14, details how a black hole found at the heart of one of two colliding galaxies (dubbed the Arp 299) pulled a closely wandering star, then ripped into it violently. This extraordinary event, called a tidal disruption event, occurred almost 150 million light-years away from Earth.
This supermassive black hole is reportedly 20 million times bigger compared to the sun, while the star is over twice as large as the sun.
The Decade-Long Observations
Back in 2005, scientists caught a stunning burst of infrared emission emanating from one of the Arp 299 galaxies' nucleus. A few months later, they observed another source giving off radio emissions in the same region of Arp 299.
Seppo Mattila from the University of Turku explains that this brand-new object appeared bright when observed using infrared and radio wavelengths. However, it did not when using X-rays and visible light.
"The most likely explanation is that thick interstellar gas and dust near the galaxy's center absorbed the X-rays and visible light, then re-radiated it as infrared," Mattila continues.
Over the following decade, scientists monitored the object using a variety of different equipment including the Very Long Baseline Array and the European VLBI Network, as well as other different radio telescopes. The data revealed how the source of these emissions stretches in a single direction at around 25 percent of light speed — the way a jet would.
Supermassive black holes pull in materials due to their gravitational pull, the material creates a rotating disk around the black hole, resulting in jets made of particles getting launched outward.
Within the years and years of observations, this jet released a massive energy in the form of infrared and radio waves, researchers told Space.com. Specifically, roughly 125 billion times of the sun's energy releases every year.
What The Discovery Means
The team's analyses highlight the potential of infrared and radio telescopes in the observation of tidal disruption events. Since the emissions are not detectable in visible light or even X-ray wavelengths, this opens up endless of possibilities using other tools.
"How many similar events are we missing in dusty centers of galaxies that would only be detectable by infrared and radio observations but be completely invisible in the optical light?" Mattila points out.