The missing links of neutron star evolution in the eROSITA all-sky X-ray survey

A M Pires

doi:10.1088/1742-6596/932/1/012008

Abstract

The observational manifestation of a neutron star is strongly connected with the properties of its magnetic field. During the star’s lifetime, the field strength and its changes dominate the thermo-rotational evolution and the source phenomenology across the electromagnetic spectrum. Signatures of magnetic field evolution are best traced among elusive groups of X-ray emitting isolated neutron stars (INSs), which are mostly quiet in the radio and γ-ray wavelengths. It is thus important to investigate and survey INSs in X-rays in the hope of discovering peculiar sources and the long-sought missing links that will help us to advance our understanding of neutron star evolution. The Extended Röntgen Survey with an Imaging Telescope Array (eROSITA), the primary instrument on the forthcoming Spectrum-RG mission, will scan the X-ray sky with unprecedented sensitivity and resolution. The survey has thus the unique potential to unveil the X-ray faint end of the neutron star population and probe sources that cannot be assessed by standard pulsar surveys.

Highlights

An isolated neutron star (INS) radiates at the expense of its rotational, thermal, and magnetic energy
About 50 peculiar X-ray emitting sources are not detected by radio and γ-ray pulsar surveys: they are the young and energetic magnetars, usually identified by their remarkable spectral properties and bursts of high energy emission [11]; the local group of thermally emitting middle-aged INSs discovered by ROSAT and dubbed the magnificent seven (M7) [22]; and the young and seemingly weakly-magnetised central compact objects (CCOs), which are thermal X-ray sources located near the centre of supernova remnants [3]
Our study indicates an expected number of up to ∼ 85 − 95 thermally emitting INSs2 to be detected in the eROSITA all-sky survey (eRASS) with more than 30 counts (0.2−2 keV)

Summary

Introduction

An isolated neutron star (INS) radiates at the expense of its rotational, thermal, and magnetic energy. The population of over 2,600 neutron stars observed in our Galaxy is dominated by radio pulsars [14].

Results

Conclusion