The pulsar population of Omega Centauri: New TRAPUM searches, timing, and cluster dynamics with MeerKAT and Parkes
Year: 2026
Type: article
Abstract: -3 $. We updated the timing solutions for pulsars A--E, obtained the first timing solutions for G, H, and K, and updated the orbital parameters for I, L, N, and Q. The latter three, I, N, and Q, have significantly longer orbital periods (P_ =1--7,days) than previously reported. Pulsars B, G, H, K, and L are black widows (P_ =2--4,hours); I is a wide-orbit (P_ =3.50,days) MSP with a light ∼0.05,M_⊙ companion; N and Q have ∼0.25,M_⊙ companions; and N shows a significant orbital eccentricity (e = 0.093). We folded Fermi-LAT and NICER photons to search for high-energy pulsations, but failed to detect them from individual MSPs. Significant spin period derivatives were measured for eight MSPs and interpreted as arising from the cluster gravitational potential. The inferred line-of-sight accelerations are consistent with a King-model gravitational potential, and allow us to set an upper central black hole mass limit of M_ <8 ,M$_⊙ at 90% confidence. The high fraction of isolated MSPs (58%) and black widow systems (63% of binaries), and possibly the eccentricity of N, are difficult to reconcile with MSP population predictions based solely on encounter rates. Instead, these properties require alternative formation channels or reflect the complex evolutionary history of Omega Centauri, with part of its MSP population having formed in denser environments than those observed today. b b b BH 4
Source: Astronomy and Astrophysics
Authors: Miquel Colom i Bernadich, Shi Dai, Federico Abbate, Matthew Kerr, Matteo Bachetti, Yash Bhargava, Sarah Buchner, Simon Johnston, Marta Burgay, Andrea Possenti, Rouhin Nag, Alessandro Ridolfi, Amodio Carleo, Alessandro Corongiu, Paulo C. C. Freire, Fernando Camilo, Weiwei Chen, Mario Cadelano, Dhanraj Risbud, Prajwal V. Padmanabh, David J. Champion, Michael Kramer, Benjamin Stappers, Maciej Serylak, Vishnu Balakrishnan, Matthew Bailes, Arunima Dutta, Laila Vleeschower, Vivek Venkatraman Krishnan, Yunpeng Men, Ewan Barr
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7140190147