High-Precision X-ray Timing of Three Millisecond Pulsars with NICER: Stability Estimates and Comparison with Radio

Abstract

The Neutron Star Interior Composition Explorer (NICER) is an X-ray astrophysics payload on the International Space Station. It enables unprecedented high-precision timing of millisecond pulsars without the pulse broadening and delays due to dispersion and scattering within the interstellar medium that plague radio timing. We present initial timing results from a year of data on the millisecond pulsars PSR B1937+21 and PSR J0218+4232, and nine months of data on PSR B1821-24. NICER time-of-arrival uncertainties for the three pulsars are consistent with theoretical lower bounds and simulations based on their pulse shape templates and average source and background photon count rates. To estimate timing stability, we use the ${\sigma }_z$ measure, which is based on the average of the cubic coefficients of polynomial fits to subsets of timing residuals. So far we are achieving timing stabilities ${\sigma }_z\approx 3\times 10^{-14}$ for PSR B1937+21 and on the order of $10^{-12}$ for PSRs B1821$-$24 and J0218+4232. Within the span of our \textit{NICER} data we do not yet see the characteristic break point in the slope of ${\sigma }_z$; detection of such a break would indicate that further improvement in the cumulative root-mean-square (RMS) timing residual is limited by timing noise. We see this break point in our comparison radio data sets for PSR B1821-24 and PSR B1937+21 on time scales of $>2$ years.

arXiv comment30 pages, 15 figures; accepted to ApJ

References in corpus (26)

• Astropy: A Community Python Package for Astronomy
• Observation of Gravitational Waves from a Binary Black Hole Merger
• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• TEMPO2, a new pulsar timing package. I: Overview
• Tempo2, a new pulsar timing package. II: The timing model and precision estimates
• The NANOGrav 11-year Data Set: High-precision timing of 45 Millisecond Pulsars
• The Parkes Pulsar Timing Array Project
• Validation of the equilibrium model for galaxy evolution to z~3 through molecular gas and dust observations of lensed star-forming galaxies
• Precise Gamma-Ray Timing and Radio Observations of 17 Fermi Gamma-Ray Pulsars
• The NANOGrav Nine-year Data Set: Observations, Arrival Time Measurements, and Analysis of 37 Millisecond Pulsars
• The H-test probability distribution revisited: Improved sensitivity
• XMM-Newton observations of four millisecond pulsars
• Pulsed Gamma Rays from the Original Millisecond and Black Widow Pulsars: a case for Caustic Radio Emission?
• Deep XMM-Newton Spectroscopic and Timing Observations of the Isolated Radio Millisecond Pulsar PSR J0030+0451
• RXTE Absolute Timing Results for the Pulsars B1821-24 and B1509-58
• Green Bank Telescope Studies of Giant Pulses from Millisecond Pulsars
• High resolution spatial and timing observations of millisecond pulsar PSR J0218+4232 with Chandra
• Modelling and mitigating refractive propagation effects in precision pulsar timing observations
• XMM-Newton spectral and timing observations of the millisecond pulsar PSR J0218+4232
• BeppoSAX observation of PSR B1937+21
• Micro-second Timing of PSR B1821-24 with Chandra/HRC-S
• Detection of Pulsed X-ray Emission from The Fastest Millisecond Pulsar PSR B1937+21 with ASCA
• XMM-Newton spectral and timing analysis of the faint millisecond pulsars PSR J0751+1807 and PSR J1012+5307
• NuSTAR Hard X-ray Observations of the Energetic Millisecond Pulsars PSR B1821-24, PSR B1937+21, and PSR J0218+4232
• High-Energy Emission of the First Millisecond Pulsar
• The phase of the radio and X-ray pulses of PSR B1937+21

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• A Detection of Red Noise in PSR J1824$-$2452A and Projections for PSR B1937+21 using NICER X-ray Timing Data
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