Probing the formation history of the nuclear star cluster at the Galactic Centre with millisecond pulsars

Abstract

The origin of the Nuclear Star Cluster in the centre of our Galaxy is still unknown. One possibility is that it formed after the disruption of stellar clusters that spiralled into the Galactic Centre due to dynamical friction. We trace the formation of the Nuclear Star Cluster around the central black hole, using state-of-the-art N-body simulations, and follow the dynamics of the neutron stars born in the clusters. We then estimate the number of Millisecond Pulsars (MSPs) that are released in the Nuclear Star Cluster, during its formation. The assembly and tidal dismemberment of globular clusters lead to a population of MSPs distributed over a radius of about 20 pc, with a peak near 3 pc. No clustering is found on the sub-parsec scale. We simulate the detectability of this population with future radio telescopes like the MeerKAT radio telescope and SKA1, and find that about of order ten MSPs can be observed over this large volume, with a paucity of MSPs within the central parsec. This helps discriminating this scenario from the in-situ formation model for the Nuclear Star Cluster that would predict an over abundance of MSPs closer to the black hole. We then discuss the potential contribution of our MSP population to the gamma-ray excess at the Galactic Centre.

11 pages, 8 figures, accepted for publication in MNRAS

References in corpus (18)

• The ATNF Pulsar Catalogue
• The Parkes multibeam pulsar survey: VI. Discovery and timing of 142 pulsars and a Galactic population analysis
• The ACS Virgo Cluster Survey. VIII. The Nuclei of Early-Type Galaxies
• An Improved Distance and Mass Estimate for Sgr A* from a Multistar Orbit Analysis
• Stellar remnants in galactic nuclei: mass segregation
• The old nuclear star cluster in the Milky Way: dynamics, mass, statistical parallax, and black hole mass
• Nuclear star clusters in 228 spiral galaxies in the HST/WFPC2 archive: catalogue and comparison to other stellar systems
• Large scale kinematics and dynamical modelling of the Milky Way nuclear star cluster
• Measuring Consistent Masses for 25 Milky Way Globular Clusters
• The Globular Cluster Migratory Origin of Nuclear Star Clusters
• Discovery of two pulsars towards the Galactic Centre
• Henize 2-10: the ongoing formation of a nuclear star cluster around a massive black hole
• On the rotation of nuclear star clusters formed by cluster-inspirals
• On Detecting Millisecond Pulsars at the Galactic Center
• Formation and evolution of nuclear star clusters with in-situ star-formation: Nuclear cores and age segregation
• Lack of nuclear clusters in dwarf spheroidal galaxies: implications for massive black holes formation and the cusp/core problem
• Pulsars in Globular Clusters
• The MEGaN project I. Missing formation of massive nuclear clusters and tidal disruption events by star clusters - massive black hole interactions

Cited by in corpus (14)

• Birth, life, and death of black hole binaries around supermassive black holes: dynamical evolution of gravitational wave sources
• Star formation at the Galactic Centre: coevolution of multiple young stellar discs
• Close stellar encounters at the Galactic Centre I: The effect on the observed stellar populations
• Compact Binary Merger Rate in Dark-Matter Spikes
• Abundance ties: Nephele and the globular cluster population accreted with $\omega$ Cen. Based on APOGEE DR17 and Gaia EDR3
• Millisecond Pulsar Kicks Cause Difficulties in Explaining the Galactic Center Gamma-Ray Excess
• Millisecond Pulsars in Dense Star Clusters: Evolution, Scaling Relations, and the Galactic-Center Gamma-ray Excess
• Searching for clues of past binary supermassive black hole mergers in nuclear star clusters
• Relativistic scattering of a fast spinning neutron star by a massive black hole
• Compact Binary Merger Rate with Modified Gravity in Dark-Matter Spikes
• A Wide Metallicity Range for Gyr-old Stars in the Nuclear Star Cluster
• Nuclear star clusters as probes of dark matter halos: the case of the Sagittarius Dwarf Spheroidal Galaxy
• A Fermi-LAT Study of Globular Cluster Dynamical Evolution in the Milky Way: Millisecond Pulsars as the Probe
• On the Deepest Search for Galactic Center Pulsars and an Examination of an Intriguing Millisecond Pulsar Candidate