SIMBAD references

We investigate the vertical structure and element distribution of neutrino-dominated accretion flows around black holes in spherical coordinates using the reasonable nuclear statistical equilibrium. According to our calculations, heavy nuclei tend to be produced in a thin region near the disk surface, whose mass fractions are primarily determined by the accretion rate and vertical distribution of temperature and density. In this thin region, we find that ⁵⁶Ni is dominant for the flow with a low accretion rate (e.g., 0.05 M_☉/s), but ⁵⁶Fe is dominant for the flow with a high accretion rate (e.g., 1 M_☉/s). The dominant ⁵⁶Ni in the aforementioned region may provide a clue to understanding the bumps in the optical light curve of core-collapse supernovae.