First ever observation of a star being torn apart by a black hole
Astronomers observed the formation and expansion of a fast-moving jet of ejected material when the powerful gravity of a supermassive black hole ripped apart a star wandering too close to it. This is the first ever direct observation of a black hole devouring a star.
Scientists tracked the event with a radio telescopeóin and telescopesów recording infrared images. The black hole ripped apart a star in a pair of colliding Arp 299 galaxies located about 150 millionóIn light years from Earth.
At the core of one of these galaxies, a black hole 20 millionów more massive than our sun, ripped apart a star twice as massive as our star, setting off a chain of events thatóre revealed important detailsóły of this violent encounter.
Most of the time, black holes orbit quietly in space. Something has to enter their gravitational field for them to become active, and when it does, it is a spectacular event. – Most of the time black holes do not devour anything. They are in a quiet phase of their existence – explained Miguel Perez-Torres of the Institute of Astrophysics in Granada.
So far, only a few such events called TDEs (tidal disruption events) have been observed and never directly. Although theorists have long believed that these events are common, speculating that material torn from the star forms a rotating disk wokó³ black hole, whichóry emits intense radiation in the X-ray and visible ranges and leads to the release of a jetóin the matter from the poleóin the disk, whichóre in turn moving at speeds close to the speed of light.
– We have never before been able to directly observe the formation and evolution of a jet from one of these events – said Perez-Torres, coółautor of publications on the subject in „Science”.
On January 30, 2005, astronomers using the William Herschel telescope in the Canary Islands discovered distinct infrared emission coming from the nucleus of one of the colliding galaxies in Arp 299. SourceóThe source of the emission was confirmed a few months póSource by researchers working at the Very Long Baseline Array (VLBA) telescope. This was the first signal of a coming event, whichóre named Arp 299-B AT1.
– As time passed, the new object remained bright in infrared and radio waves, but not in visible light and X-rays. The most likely explanation was that the dense interstellar gas and dust near the center of the galaxy absorbs X-rays and visible light and then gives them off in the infrared, said Seppo Mattila of the University of Turku in Finland.
For the next decade, astronomers observed this region of the cosmos zaróinno by radio telescopes and infrared telescopes. They observed the emission moving outward at high speed and in one direction. Their patience was rewarded. Researchers obtained direct observations of the jetsów.
– TDEs are a unique opportunity to expand our knowledge of the formation and evolution of jetsóIn the vicinity of the massive objectów – Perez-Torres said. Arp 299-B AT1 provides an insight into how theób relativistic jets form, and how supermassive black holes grow to their enormous sizeów.
As the scientists admit, they made the observation by accident. It was made as part of a project in which theórym looked for supernovae in colliding galaxies, and Arp 299 is the perfect place for such observations. Colliding galaxies have even been named „supernova factory”. Anyway, the Arp 299-B AT1 event was also initially thought to be a supernova. It was not until 2011 that more accurate observations made it possible to identify this phenomenon.