An Investigation into Nucleosynthesis in Common Envelope Neutron Star Systems

In this thesis, the burning processes in common envelope neutron star systems are investigated. The production of key isotopes which have been shown to be overproduced in observations of HV2112 is investigated, and finds that for a large range of accretion rates and depths into the neutron star envelope, significant enrichment in these elements is achieved. The production of p nuclei is also looked and it is found that at an accretion rate of M ̇ = 103M⊙/yr, 7 of the investigated isotopes are significantly enriched in the processed material. Finally, the extent of nucleosynthesis for different accretion rates and depths is discussed and it is found that for a wide range of these parameters nucleosynthesis proceeds into the A ≈ 130 mass range, unexpected in the rp-process due to α unbound cycles. This may indicate the action of α capture and provides a method for the synthesis of massive, proton rich nuclei. Further study would be necessary to determine the exact increase of material in this mass range. These results together provide a possibility for observational candidates in the spectrum of HV2112, and also motivation for a full hydrodynamic model of the system to fully investigate the nucleosynthesis in the system.