A joint MeerKAT and Parkes view of Omega Centauri: New TRAPUM Searches and Pulsar Timing

Fuente: arXiv
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Autori principali: Bernadich, Miquel Colom i, Dai, Shi, Abbate, Federico, Kerr, Matthew, Bachetti, Matteo, Bhargava, Yash, Buchner, Sarah, Johnston, Simon, Burgay, Marta, Possenti, Andrea, Nag, Rouhin, Ridolfi, Alessandro, Carleo, Amodio, Corongiu, Alessandro, Freire, Paulo C. C., Camilo, Fernando, Chen, Weiwei, Cadelano, Mario, Risbud, Dhanraj, Padmanabh, Prajwal V., Champion, David J., Kramer, Michael, Stappers, Benjamin, Serylak, Maciej, Balakrishnan, Vishnu, Bailes, Matthew, Dutta, Arunima, Calas, Laila Vleeschower, Krishnan, Vivek Venkatraman, Men, Yunpeng
Natura: Preprint
Pubblicazione: 2026
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author Bernadich, Miquel Colom i
Dai, Shi
Abbate, Federico
Kerr, Matthew
Bachetti, Matteo
Bhargava, Yash
Buchner, Sarah
Johnston, Simon
Burgay, Marta
Possenti, Andrea
Nag, Rouhin
Ridolfi, Alessandro
Carleo, Amodio
Corongiu, Alessandro
Freire, Paulo C. C.
Camilo, Fernando
Chen, Weiwei
Cadelano, Mario
Risbud, Dhanraj
Padmanabh, Prajwal V.
Champion, David J.
Kramer, Michael
Stappers, Benjamin
Serylak, Maciej
Balakrishnan, Vishnu
Bailes, Matthew
Dutta, Arunima
Calas, Laila Vleeschower
Krishnan, Vivek Venkatraman
Men, Yunpeng
author_facet Bernadich, Miquel Colom i
Dai, Shi
Abbate, Federico
Kerr, Matthew
Bachetti, Matteo
Bhargava, Yash
Buchner, Sarah
Johnston, Simon
Burgay, Marta
Possenti, Andrea
Nag, Rouhin
Ridolfi, Alessandro
Carleo, Amodio
Corongiu, Alessandro
Freire, Paulo C. C.
Camilo, Fernando
Chen, Weiwei
Cadelano, Mario
Risbud, Dhanraj
Padmanabh, Prajwal V.
Champion, David J.
Kramer, Michael
Stappers, Benjamin
Serylak, Maciej
Balakrishnan, Vishnu
Bailes, Matthew
Dutta, Arunima
Calas, Laila Vleeschower
Krishnan, Vivek Venkatraman
Men, Yunpeng
contents Millisecond pulsars (MSPs) are powerful probes of globular clusters (GCs), tracing stellar evolution, cluster dynamics, and the local gravitational potential. We investigate the MSP population in GC Omega Centauri. We perform Fourier-domain acceleration and jerk searches on MeerKAT observations, and carry out pulsar timing using MeerKAT and Parkes Murriyang data spanning 2021-2025. We fold Fermi LAT and NICER photons using updated radio ephemerides to search for high-energy pulsations. We discover a new isolated MSP, PSR J1326-4728S (hereafter S), with a spin period of 4.538 ms and a dispersion measure of 96.24 cm$^3$pc. We update the orbital parameters of all known binary systems, with those of I, N, and Q differing significantly from previous estimates, and obtain new timing solutions for G, H, and K. Pulsars B, G, H, K, and L exhibit black widow-like properties, I, N and Q are found in wider binaries, with N and Q having >0.2 M$_\odot$ companions, and N showing a significant orbital eccentricity (e=0.093). Significant spin period derivatives are measured for eight pulsars and interpreted as arising from the cluster gravitational potential. No pulsed high-energy emission is detected from individual pulsars. The inferred line-of-sight accelerations are consistent with a King-model gravitational potential. While our measurements are insensitive to an intermediate-mass black hole with mass 10$^3$-10$^4$ M$_\odot$, they place an upper limit of <10$^5$ M$_\odot$ at 90% confidence. The high fraction of isolated MSPs and black widows systems, and possibly the eccentricity of N, are difficult to reconcile with MSP population predictions based solely on encounter rates. Instead, these properties likely reflect the complex evolutionary history of Omega Centauri, with part of its MSP population having formed in denser environments than the one observed today.
format Preprint
id arxiv_https___arxiv_org_abs_2603_21845
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle A joint MeerKAT and Parkes view of Omega Centauri: New TRAPUM Searches and Pulsar Timing
Bernadich, Miquel Colom i
Dai, Shi
Abbate, Federico
Kerr, Matthew
Bachetti, Matteo
Bhargava, Yash
Buchner, Sarah
Johnston, Simon
Burgay, Marta
Possenti, Andrea
Nag, Rouhin
Ridolfi, Alessandro
Carleo, Amodio
Corongiu, Alessandro
Freire, Paulo C. C.
Camilo, Fernando
Chen, Weiwei
Cadelano, Mario
Risbud, Dhanraj
Padmanabh, Prajwal V.
Champion, David J.
Kramer, Michael
Stappers, Benjamin
Serylak, Maciej
Balakrishnan, Vishnu
Bailes, Matthew
Dutta, Arunima
Calas, Laila Vleeschower
Krishnan, Vivek Venkatraman
Men, Yunpeng
High Energy Astrophysical Phenomena
Millisecond pulsars (MSPs) are powerful probes of globular clusters (GCs), tracing stellar evolution, cluster dynamics, and the local gravitational potential. We investigate the MSP population in GC Omega Centauri. We perform Fourier-domain acceleration and jerk searches on MeerKAT observations, and carry out pulsar timing using MeerKAT and Parkes Murriyang data spanning 2021-2025. We fold Fermi LAT and NICER photons using updated radio ephemerides to search for high-energy pulsations. We discover a new isolated MSP, PSR J1326-4728S (hereafter S), with a spin period of 4.538 ms and a dispersion measure of 96.24 cm$^3$pc. We update the orbital parameters of all known binary systems, with those of I, N, and Q differing significantly from previous estimates, and obtain new timing solutions for G, H, and K. Pulsars B, G, H, K, and L exhibit black widow-like properties, I, N and Q are found in wider binaries, with N and Q having >0.2 M$_\odot$ companions, and N showing a significant orbital eccentricity (e=0.093). Significant spin period derivatives are measured for eight pulsars and interpreted as arising from the cluster gravitational potential. No pulsed high-energy emission is detected from individual pulsars. The inferred line-of-sight accelerations are consistent with a King-model gravitational potential. While our measurements are insensitive to an intermediate-mass black hole with mass 10$^3$-10$^4$ M$_\odot$, they place an upper limit of <10$^5$ M$_\odot$ at 90% confidence. The high fraction of isolated MSPs and black widows systems, and possibly the eccentricity of N, are difficult to reconcile with MSP population predictions based solely on encounter rates. Instead, these properties likely reflect the complex evolutionary history of Omega Centauri, with part of its MSP population having formed in denser environments than the one observed today.
title A joint MeerKAT and Parkes view of Omega Centauri: New TRAPUM Searches and Pulsar Timing
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2603.21845