2008ApJ...681...96H

Nucleosynthesis could take place in the hot regions of accretion and outflow around a black hole. We here investigate possible composition changes due to nuclear reaction processes in an accretion disk by calculating a set of self-similar solutions of an advection-dominated accretion flow. We find that ²⁶Al, ⁵¹Cr, ⁵³Mn, and ⁵⁵Fe produced in the accretion flow with a heating factor f=0.001 are significantly overabundant compared to solar abundances, and could contribute to metal-contaminated galaxies. We find a richness of protons and neutrons due to photodisintegration in very hot flows. We also discuss nucleosynthesis in outflow regions via an expansion burning reaction process; the abundances of some species could increase further due to such nuclear reactions. A possible new origin of ²⁶Al, which depends on the quantity of stellar-mass black holes and the mass of the host galaxy, is also discussed.