English

Eight new millisecond pulsars from the first MeerKAT globular cluster census

High Energy Astrophysical Phenomena 2021-03-24 v1

Abstract

We have used the central 44 antennas of the new 64-dish MeerKAT radio telescope array to conduct a deep search for new pulsars in the core of nine globular clusters. This has led to the discovery of eight new millisecond pulsars in six different clusters. Two new binaries, 47 Tuc ac and 47 Tuc ad, are eclipsing "spiders", featuring compact orbits (0.32\lesssim 0.32 days), very low-mass companions and regular occultations of their pulsed emission. The other three new binary pulsars (NGC 6624G, M62G, and Ter 5 an) are in wider (>0.7> 0.7 days) orbits, with companions that are likely to be white dwarfs or neutron stars. NGC 6624G has a large eccentricity of e0.38e\simeq 0.38, which enabled us to detect the rate of advance of periastron. This suggests that the system is massive, with a total mass of Mtot=2.65±0.07M{\rm tot} = 2.65 \pm 0.07 M_{\odot}. Likewise, for Ter 5 an, with e0.0066e \simeq 0.0066, we obtain Mtot=2.97±0.52M{\rm tot}= 2.97 \pm 0.52 M_{\odot}. The other three new discoveries (NGC 6522D, NGC 6624H and NGC 6752F) are faint isolated pulsars. Finally, we have used the whole MeerKAT array and synthesized 288 beams, covering an area of 2\sim2 arcmin in radius around the center of NGC 6624. This has allowed us to localize many of the pulsars in the cluster, demonstrating the beamforming capabilities of the TRAPUM software backend and paving the way for the upcoming MeerKAT globular cluster pulsar survey.

Keywords

Cite

@article{arxiv.2103.04800,
  title  = {Eight new millisecond pulsars from the first MeerKAT globular cluster census},
  author = {A. Ridolfi and T. Gautam and P. C. C. Freire and S. M. Ransom and S. J. Buchner and A. Possenti and V. Venkatraman Krishnan and M. Bailes and M. Kramer and B. W. Stappers and F. Abbate and E. D. Barr and M. Burgay and F. Camilo and A. Corongiu and A. Jameson and P. V. Padmanabh and L. Vleeschower and D. J. Champion and M. Geyer and A. Karastergiou and R. Karuppusamy and A. Parthasarathy and D. J. Reardon and M. Serylak and R. M. Shannon and R. Spiewak},
  journal= {arXiv preprint arXiv:2103.04800},
  year   = {2021}
}

Comments

20 pages, 10 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society

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