Neutron star mass in dark matter clumps

Abstract

This paper investigates a hypothesis proposed in previous research relating neutron star (NS) mass and its dark matter (DM) accumulation. As DM accumulates, NS mass decreases, predicting lower NS masses toward the Galactic center. Due to limited NSs data near the galactic center, we examine NSs located within DM clumps. Using the CLUMPY code simulations, we determine the DM clumps distribution, with masses from 10 to 108 M⊙ and scales from 10−3 to 10 kpc. These clumps’ DM exhibit a peak at the center, tapering toward the outskirts, resembling our Galaxy’s DM distribution. We analyse these DM clumps’ NS mass variations, considering diverse DM particle masses and galaxy types. We find relatively stable NS mass within 0.01 to 5 kpc from the clump center. This stability supports the initial hypothesis, particularly for NSs located beyond 0.01 kpc from the clump center, where NS mass reaches a plateau around 0.1 kpc. Nevertheless, NS mass near the clump’s periphery reveals spatial dependence: NS position within DM clumps influences its mass in Milky Way-type galaxies. Moreover, this dependence varies with the DM model considered. In summary, our study investigates the proposed link between NS mass and DM accumulation by examining NSs within DM clumps. While NS mass remains stable at certain distances from the clump center, spatial dependencies arise near the clump’s outer regions, contingent on the specific DM model.

Exploring the Distribution and Impact of Bosonic Dark Matter in Neutron Stars

“…In this regard, the accretion of DM might occur during star evolution or over the lifetime of an NS. It is argued that high capture rates are more likely to happen toward the center of galaxies, where the density of DM is increasing [15][16][17]. Moreover, DM production inside NSs and supernova explosions can lead to large values of the DM fraction [5,6,18,19].…”