Giant ‘Cosmic tail’ Discovered in Galaxy NGCโค 3627, Potentially Left โby Roaming Black Hole
A newly discovered, exceptionally long โand โขwell-defined trail of โgas and dust in the galaxy NGC 3627 is sparking debate among astronomers, with a leading theory suggesting it was โcreated by a supermassive black hole hurtling through the galactic disk. The structure, described as the clearest and longest โ”contrail” ever found โoutside the Milky Way, stretches for an extraordinary distance and offers โa rare โฃglimpse โฃinto the dynamic processes shaping galaxies.
Theโฃ trail appears as a thin, elongated line distinct from NGC 3627’s spiral arms. Researchers believe the phenomenon originated approximatelyโข 20 million years ago – a recent event on โcosmic timescales,โฃ given the milky Way’s age of over 13 billion years. A theoretical model developed in 2021 by researcher Li proposes โขthe trail โคformed when a dense object aroundโข 10 millionโ times the mass of our sun, likely a black hole, traversed โคthe galaxy at roughlyโค 300 kilometers per second (186 miles per second). This high-speed passage would have compressed and swept out gas in โขits wake,creating โthe observed โฃ”cosmic tail” andโ the turbulence detected within it.
“Its length is extraordinary, and โits shape is very well defined compared โคto similar structures in other galaxies,” stated zhao, a researcher involved inโค the study.
While the blackโฃ hole hypothesisโฃ is currently favored, scientists haven’t ruled out the possibility that the trailโ couldโ be the remnant of a dense โcore from a dwarf galaxy passing near NGC 3627.Distinguishing between these scenariosโฃ remains challenging with current data. โฃ”If the object isโ a faint dwarf galaxy, it is too โfar away to โคdetect directly,” explained Zhao.
The research โteam, analyzing dataโ from the โPHANGS survey, intends โขto continue searching for similar โขstructures in otherโฃ galaxies. Thay hope these future discoveries will help map โฃthe โpopulation of massive, freely moving dark objects – including potentially โwandering black holes – and provide new insights into galacticโ evolution and interactions. “Understanding how โfrequently enough phenomena like this occur can give us new insights into how galaxies evolve and interact with hidden objects in the universe,” Zhao added.
Theโ findings are currently available as a โpre-review โpublication on the arXiv server.