The impact of precession on the observed population of ULXs. Issue 2 (23rd October 2021)

• Record Type: Journal Article
• Authors: Khan, Norman; Middleton, Matthew J; Wiktorowicz, Grzegorz; Dauser, Thomas; Roberts, Timothy P; Wilms, Joern
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 509:Issue 2(2022)
• Page Start: 2493
• Page End: 2506
• Publication Date: 2021-10-23
• Subjects: stars: black holes -- stars: neutron -- X-rays: binaries; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab3049
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: The discovery of neutron stars (NSs) powering several ultraluminous X-ray sources (ULXs) raises important questions about the nature of the underlying population. In this paper, we build on previous work studying simulated populations by incorporating a model where the emission originates from a precessing, geometrically beamed wind-cone, created by a supercritical inflow. We obtain estimates – independent of the prescription for the precession period of the wind – for the relative number of ULXs that are potentially visible (persistent or transient) for a range of underlying factors such as the relative abundance of black holes or NSs within the population, maximum precessional angle, and low-mass X-ray binary duty cycle. We make initial comparisons to existing data using a catalogue compiled from XMM–Newton . Finally, based on estimates for the precession period, we determine how the eROSITA all-sky survey ( eRASS ) will be able to constrain the underlying demographic.