A strange streak of young stars is evidence of a runaway supermassive black hole, study finds

Astronomers have noticed a candidate supermassive black hole working away from its house galaxy, hurtling by way of space at a velocity of about 4 million miles per hour for the previous 39 million years.

A Yale College-led workforce utilizing NASA’s Hubble Area Telescope and W. M. Keck Observatory on Maunakea in Hawaiʻi found an uncommon, very skinny, virtually straight streak of younger stars and shocked fuel—presumably the path the black hole left behind because it escaped.

The findings are outlined in a examine printed in The Astrophysical Journal Letters.

“One thing like this has by no means been seen anyplace within the universe,” mentioned Pieter van Dokkum, professor of astronomy and physics at Yale College and lead creator of the examine. “We have identified for a very long time that supermassive black holes exist and it had been predicted for about 50 years that they might generally be ejected from galaxies. If confirmed, this might be the primary proof of a runaway supermassive black hole, proving this prediction.”

Van Dokkum’s workforce first detected the lengthy characteristic with NASA’s Hubble Area Telescope. To get a better look, they carried out follow-up observations utilizing Keck Observatory’s Low Decision Imaging Spectrometer (LRIS) and Close to Infrared Echellette Spectrograph (NIRES).

The Keck Observatory knowledge revealed the streak of stars measured a exceptional 200,000 light-years in size and prolonged from a compact, lively star-forming galaxy whose mild took about 7.6 billion years to achieve Earth. The path is nearly half as brilliant because the host galaxy it’s linked to, indicating it accommodates an abundance of recent stars.

“We expect we’re seeing a wake behind the black hole the place the fuel cools and is ready to kind stars. So, we’re taking a look at star formation trailing the black hole,” mentioned van Dokkum. “What we’re seeing is the aftermath. Just like the wake behind a ship, we’re seeing the wake behind the black hole.”

Keck Observatory additionally confirmed a brilliant knot of ionized fuel on the prime of the wake—seemingly the positioning of the black hole itself. Additionally, the linear characteristic’s house galaxy seems to be lacking a black hole at its heart, or at the least doesn’t have one that’s actively feasting on materials and producing highly effective jets of vitality that telescopes can detect.

If the slim wake of stars and fuel was certainly created by a black hole dislodged from its house galaxy, astronomers have a possible clarification for its origin story. First, two galaxies, each containing a supermassive black hole inside their cores, merge. Subsequent, because the black holes whiz round one another in a binary dance on the heart of the newly- merged galaxy, a 3rd supermassive black hole inside one other galaxy intrudes on the couple. The trio’s interplay with each other then creates an unstable scenario that generates sufficient velocity to torpedo one of many three black holes out.

As a subsequent step, van Dokkum and his workforce at the moment are in search of to substantiate whether or not their discovery is actually a runaway black hole; they’ve utilized for time on NASA’s James Webb Area Telescope and Chandra X-ray Observatory to conduct follow-up observations.

As a result of the linear streak of new child stars and shocked fuel is so hanging, van Dokkum says it must be easy to search out different objects prefer it in present and future knowledge, akin to with NASA’s upcoming Nancy Grace Roman Area Telescope.

“A lot of what we do is hypothesis testing, or refining earlier measurements, however generally there may be this bolt out of the blue of a totally unanticipated discovery. That’s uncommon, however it’s the finest!” mentioned van Dokkum.

“Going from noticing the streak and pondering ʻhey that is bizarre’ to this paper was so extremely enjoyable and satisfying as we have been all studying each step of the way in which,” mentioned co-author Imad Pasha, a Yale College graduate pupil on van Dokkum’s analysis workforce.