Eight new MSPs in NGC 6440 and NGC 6441

Paulo C. C. Freire; Scott M. Ransom; Steve Begin; Ingrid H. Stairs; Jason W. T. Hessels; Lucille H. Frey; Fernando Camilo

doi:10.1063/1.2900307

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arXiv · 0711.2028

Eight new MSPs in NGC 6440 and NGC 6441

Paulo C. C. Freire·Scott M. Ransom·Steve Begin·Ingrid H. Stairs·Jason W. T. Hessels·Lucille H. Frey·Fernando Camilo

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Abstract

We report the discovery of five new millisecond pulsars in the globular cluster NGC 6440 and three new ones in NGC 6441; each cluster has one previously known pulsar. Four of the new pulsars are found in binary systems. One of the new pulsars, PSR J1748-2021B in NGC 6440, is notable for its eccentric (e = 0.57) and wide (P_b = 20.5 days) orbit. If the rate of advance of periastron is due solely to general relativity, we can estimate of the total mass of this binary system: 2.92 +/- 0.20 solar masses. This would imply an anomalously large mass for this pulsar, which could introduce important constraints in the study of the equation of state for cold neutron matter.

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Paulo C. C. Freire, Scott M. Ransom, Steve Begin, Ingrid H. Stairs, Jason W. T. Hessels, Lucille H. Frey, Fernando Camilo. 2007-11-13. Eight new MSPs in NGC 6440 and NGC 6441. https://doi.org/10.1063/1.2900307

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