A NICER View of Spectral and Profile Evolution for Three X-ray Emitting Millisecond Pulsars

ORAL

Abstract

We present two years of Neutron star Interior Composition Explorer (NICER) X-ray observations of three young and energetic rotation-powered millisecond pulsars: PSRs B1937+21, B1821−24, and J0218+4232. We fit Gaussians and Lorentzians to the pulse profiles for different energy sub-bands of the soft X-ray regime to measure the energy dependence of pulse separation and width. We find that the separation between pulse components of PSR J0218+4232 decreases with increasing energy at 3$\sigma$ confidence. Our phase-resolved spectral results provide updated constraints on the non-thermal X-ray emission of these three pulsars. The photon indices of the modeled X-ray emission spectra for each pulse component of PSR B1937+21 are inconsistent with each other at the 90\% confidence level.

*Funded by NASA NICER and by NANOGrav Physics Frontier Center

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Authors

  • Andrea Lommen

    • Haverford College

  • Dominck Rowan

    • Haverford College

  • Zaynab Ghazi

    • Bryn Mawr College

  • Lauren Lugo

    • Haverford College

  • Elizabeth Spano

    • Haverford College

  • Alice Harding

    • NASA Goddard
    • NASA Goddard Space Flight Center

  • Christo Venter

    • Centre for Space Research, North-West University, South Africa
    • North-West University

  • Renee Ludlam

    • University of Michigan

  • Paul Ray

    • Naval Research Laboratory

  • Matthew Kerr

    • Naval Research Laboratory

  • Zaven Arzoumanian

    • NASA Goddard

  • Slavko Bogdanov

    • Columbia University

  • Julia Deneva

    • Naval Research Laboratory

  • Sebastian Guillot

    • IRAP, CNRS

  • Natalia Lewandowska

    • West Virginia University

  • Craig Markwardt

    • NASA Goddard

  • Scott Ransom

    • NRAO

  • Teruaki Enoto

    • Kyoto University

  • Kent Wood

    • Naval Research Laboratory

  • Keith Gendreau

    • NASA Goddard
    • Astrophysics Science Division, NASA's Goddard Space Flight Center