The impact of precession on the observed population of ULXs. (arXiv:2110.11318v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Khan_N/0/1/0/all/0/1">Norman Khan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Middleton_M/0/1/0/all/0/1">Matthew. J. Middleton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wiktorowicz_G/0/1/0/all/0/1">Grzegorz Wiktorowicz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dauser_T/0/1/0/all/0/1">Thomas Dauser</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Roberts_T/0/1/0/all/0/1">Timothy P. Roberts</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wilms_J/0/1/0/all/0/1">Joern Wilms</a>
The discovery of neutron stars 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 super-critical 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 neutron stars within the population,
maximum precessional angle, and LMXB 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.
The discovery of neutron stars 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 super-critical 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 neutron stars within the population,
maximum precessional angle, and LMXB 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.
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