TY - JOUR
T1 - The influence of black holes on the binary population of the globular cluster Palomar 5
AU - Wang, Long
AU - Gieles, Mark
AU - Baumgardt, Holger
AU - Li, Chengyuan
AU - Pang, Xiaoying
AU - Tang, Baitian
N1 - Publisher Copyright:
© 2023 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2024/1/1
Y1 - 2024/1/1
N2 - The discovery of stellar-mass black holes (BHs) in globular clusters (GCs) raises the possibility of long-term retention of BHs within GCs. These BHs influence various astrophysical processes, including merger-driven gravitational waves and the formation of X-ray binaries. They also impact cluster dynamics by heating and creating low-density cores. Previous N-body models suggested that Palomar 5, a low-density GC with long tidal tails, may contain more than 100 BHs. To test this scenario, we conduct N-body simulations of Palomar 5 with primordial binaries to explore the influence of BHs on binary populations and the stellar mass function. Our results show that primordial binaries have minimal effect on the long-term evolution. In dense clusters with BHs, the fraction of wide binaries with periods >105 d decreases, and the disruption rate is independent of the initial period distribution. Multi-epoch spectroscopic observations of line-of-sight velocity changes can detect most bright binaries with periods below 104 d, significantly improving velocity dispersion measurements. Four BH-MS binaries in the model with BHs suggests their possible detection through the same observation method. Including primordial binaries leads to a flatter inferred mass function because of spatially unresolved binaries, leading to a better match of the observations than models without binaries, particularly in Palomar 5's inner region. Future observations should focus on the cluster velocity dispersion and binaries with periods of 104-105 d in Palomar 5's inner and tail regions to constrain BH existence.
AB - The discovery of stellar-mass black holes (BHs) in globular clusters (GCs) raises the possibility of long-term retention of BHs within GCs. These BHs influence various astrophysical processes, including merger-driven gravitational waves and the formation of X-ray binaries. They also impact cluster dynamics by heating and creating low-density cores. Previous N-body models suggested that Palomar 5, a low-density GC with long tidal tails, may contain more than 100 BHs. To test this scenario, we conduct N-body simulations of Palomar 5 with primordial binaries to explore the influence of BHs on binary populations and the stellar mass function. Our results show that primordial binaries have minimal effect on the long-term evolution. In dense clusters with BHs, the fraction of wide binaries with periods >105 d decreases, and the disruption rate is independent of the initial period distribution. Multi-epoch spectroscopic observations of line-of-sight velocity changes can detect most bright binaries with periods below 104 d, significantly improving velocity dispersion measurements. Four BH-MS binaries in the model with BHs suggests their possible detection through the same observation method. Including primordial binaries leads to a flatter inferred mass function because of spatially unresolved binaries, leading to a better match of the observations than models without binaries, particularly in Palomar 5's inner region. Future observations should focus on the cluster velocity dispersion and binaries with periods of 104-105 d in Palomar 5's inner and tail regions to constrain BH existence.
KW - binaries: general
KW - globular clusters: individual: Palomar 5
KW - methods: numerical
KW - stars: black holes
KW - techniques: radial velocities
UR - http://www.scopus.com/inward/record.url?scp=85180010009&partnerID=8YFLogxK
U2 - 10.1093/mnras/stad3657
DO - 10.1093/mnras/stad3657
M3 - Article
AN - SCOPUS:85180010009
SN - 0035-8711
VL - 527
SP - 7495
EP - 7514
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -