Searching for X-ray Pulsations from Neutron Stars Using NICER

TL;DR

This paper details NICER's new capabilities for detecting X-ray pulsations from neutron stars, outlining a 2.5 Ms observation plan targeting various neutron star types, and reports initial pulsation discoveries including from J1231-1411.

Contribution

It introduces NICER's pulsation search strategy and presents initial results, including the first detection of pulsations from J1231-1411, advancing neutron star studies.

Findings

Discovered pulsations from millisecond pulsar J1231-1411.

Established a comprehensive observation plan for neutron star pulsation searches.

Demonstrated NICER's capabilities for precise timing and low-background X-ray observations.

Abstract

The Neutron Star Interior Composition Explorer (NICER) presents an exciting new capability for exploring the modulation properties of X-ray emitting neutron stars, including large area, low background, extremely precise absolute event time stamps, superb low-energy response and flexible scheduling. The Pulsation Searches and Multiwavelength Coordination working group has designed a 2.5 Ms observing program to search for emission and characterize the modulation properties of about 30 known or suspected neutron star sources across a number of source categories. A key early goal will be to search for pulsations from millisecond pulsars that might exhibit thermal pulsations from the surface suitable for pulse profile modeling to constrain the neutron star equation of state. In addition, we will search for pulsations from transitional millisecond pulsars, isolated neutron stars, low-mass X-ray binaries (LMXBs), accretion-powered millisecond pulsars, central compact objects and other sources. We present our science plan and initial results from the first months of the NICER mission, including the discovery of pulsations from the millisecond pulsar J1231-1411.