TY - JOUR

T1 - Discoveries and timing of pulsars in M62

AU - Vleeschower, L.

AU - Corongiu, A.

AU - Stappers, B. W.

AU - Freire, P. C.C.

AU - Ridolfi, A.

AU - Abbate, F.

AU - Ransom, S. M.

AU - Possenti, A.

AU - Padmanabh, P. V.

AU - Balakrishnan, V.

AU - Kramer, M.

AU - Venkatraman Krishnan, V.

AU - Zhang, L.

AU - Bailes, M.

AU - Barr, E. D.

AU - Buchner, S.

AU - Chen, W.

N1 - Funding Information: The MeerKAT telescope is operated by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation, an agency of the Department of Science and Innov ation. SARAO ackno wledges the ongoing advice and calibration of GPS systems by the National Metrology Institute of South Africa (NMISA) and the time space reference systems department of the Paris Observatory. MeerTime data is housed on the OzSTAR supercomputer at Swinburne University of Technology. The OzSTAR program receives funding in part from the Astronomy National Collaborative Research Infrastructure Strategy (NCRIS) allocation provided by the Australian Go v ernment. The Parkes radio telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO). We ac-knowledge the Wiradjuri people as the traditional owners of the Observatory site. The Green Bank Observatory is a facility of the National Science Foundation (NSF) operated under cooperative agreement by Associated Universities, Inc. The National Radio Astronomy Observatory (NRAO) is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The authors also acknowledge MPIfR funding to contribute to MeerTime infrastructure. TRAPUM observations used the FBFUSE and APSUSE computing clusters for data acquisition, storage, and analysis. These clusters were funded and installed by the Max-Planck-Institut f\u00FCr Radioastronomie and the Max-Planck-Gesellschaft. LV acknowledges financial support from the Dean's Doctoral Scholar Award from the University of Manchester. BWS acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 694745). Part of this work has been funded using resources from the Italian National Institute for Astrophysics (INAF) Large Grant 2022 'GCjewels' (P.I. Andrea Possenti) appro v ed with the Presidential Decree 30/2022. This work was also in part supported by the 'Italian Ministry of Foreign Affairs and International Cooperation', grant number ZA23GR03. PCCF, AR, PVP, VB, MK, VVK, EDB, and WC acknowledge continuing valuable support from the Max-Planck Society. SMR is a CIFAR Fellow and is supported by the NSF Physics Frontiers Center award 2020265. VVK acknowledges financial support from the ERC starting grant, 'COMPACT' (Grant agreement number 101078094), under the European Union's Horizon Europe research and innov ation programme. MB ackno wledges support through ARC grant CE170100004. LZ acknowledges financial support from ACAMAR Postdoctoral Fellowship and the National Natural Science Foundation of China (Grant No. 12103069).

PY - 2024/5

Y1 - 2024/5

N2 - Using MeerKAT, we have discovered three new millisecond pulsars (MSPs) in the bulge globular cluster M62: M62H, M62I, and M62J. All three are in binary systems, which means all ten known pulsars in the cluster are in binaries. M62H has a planetary-mass companion with a median mass Mc, med ∼3 MJ and a mean density of ρ ∼11 g cm-3. M62I has an orbital period of 0.51 d and a Mc, med ∼0.15 M⊙. Neither of these low-mass systems exhibit eclipses. M62J has only been detected in the two Ultra High Frequency band (816 MHz) observations with a flux density S816 = 0.08 mJy. The non-detection in the L-band (1284 MHz) indicates it has a relatively steep spectrum (β < -3.1). We also present 23-yr-long timing solutions obtained using data from the Parkes 'Murriyang', Effelsberg, and MeerKAT telescopes for the six previously known pulsars. For all these pulsars, we measured the second spin-period derivatives and the rate of change of orbital period caused by the gravitational field of the cluster, and their proper motions. From these measurements, we conclude that the pulsars' maximum accelerations are consistent with the maximum cluster acceleration assuming a core-collapsed mass distribution. Studies of the eclipses of the redback M62B and the black widow M62E at four and two different frequency bands, respectively, reveal a frequency dependence with longer and asymmetric eclipses at lower frequencies. The presence of only binary MSPs in this cluster challenges models which suggest that the MSP population of core-collapsed clusters should be dominated by isolated MSPs.

AB - Using MeerKAT, we have discovered three new millisecond pulsars (MSPs) in the bulge globular cluster M62: M62H, M62I, and M62J. All three are in binary systems, which means all ten known pulsars in the cluster are in binaries. M62H has a planetary-mass companion with a median mass Mc, med ∼3 MJ and a mean density of ρ ∼11 g cm-3. M62I has an orbital period of 0.51 d and a Mc, med ∼0.15 M⊙. Neither of these low-mass systems exhibit eclipses. M62J has only been detected in the two Ultra High Frequency band (816 MHz) observations with a flux density S816 = 0.08 mJy. The non-detection in the L-band (1284 MHz) indicates it has a relatively steep spectrum (β < -3.1). We also present 23-yr-long timing solutions obtained using data from the Parkes 'Murriyang', Effelsberg, and MeerKAT telescopes for the six previously known pulsars. For all these pulsars, we measured the second spin-period derivatives and the rate of change of orbital period caused by the gravitational field of the cluster, and their proper motions. From these measurements, we conclude that the pulsars' maximum accelerations are consistent with the maximum cluster acceleration assuming a core-collapsed mass distribution. Studies of the eclipses of the redback M62B and the black widow M62E at four and two different frequency bands, respectively, reveal a frequency dependence with longer and asymmetric eclipses at lower frequencies. The presence of only binary MSPs in this cluster challenges models which suggest that the MSP population of core-collapsed clusters should be dominated by isolated MSPs.

KW - binaries: general

KW - globular clusters: individual: M62

KW - pulsars: general

KW - stars: neutron

UR - http://www.scopus.com/inward/record.url?scp=85190885806&partnerID=8YFLogxK

U2 - 10.48550/arXiv.2403.12137

DO - 10.48550/arXiv.2403.12137

M3 - Article

AN - SCOPUS:85190885806

VL - 530

SP - 1436

EP - 1456

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 2

ER -