In a groundbreaking study published in Nature Astronomy, researchers have unveiled that the star cluster Palomar 5, known for its unique wide distribution and long tidal stream stretching across the sky, may harbor a secret: a dense population of over 100 stellar-mass black holes. This discovery challenges previous expectations about the number of black holes in such clusters, suggesting that more than 20% of Palomar 5’s total mass consists of black holes, each approximately 20 times the mass of the Sun.
The team, led by astrophysicist Mark Gieles from the University of Barcelona, utilized detailed N-body simulations to explore the cluster’s evolution. They found that the presence of a significant number of black holes could explain the observed configuration of stars, as gravitational interactions likely propelled stars out of the cluster and into the surrounding tidal stream. This process not only reshapes our understanding of Palomar 5 but also hints at a common fate for globular clusters, which may eventually dissolve entirely into stellar streams.
Furthermore, this research sheds light on the potential for globular clusters to host not only stellar-mass black holes but also the elusive intermediate-mass black holes. It opens new avenues for investigating black hole populations in star clusters, offering insights into the dynamics of binary black hole mergers and the evolution of clusters themselves. This study marks a significant step forward in our comprehension of the complex interplay between black holes and star clusters in the cosmos.
Read more at ScienceAlert…