[P-PS07] Planetary Sciences

[PPS07-11] Self-consistent Conditions for ²⁶Al Injection into Protosolar Disk from a Nearby Supernova

*Ryo SAWADA¹, Tetsuo Taki¹, Hiroyuki Kurokawa¹ (1.The University of Tokyo)

Keywords:formation of the solar system, protoplanetary disks, supernovae

The early solar system contained a short-lived radionuclide, ²⁶Al (its half-life time t_1/2=0.7 Myr). The decay energy ²⁶Al is thought to have controlled the thermal evolution of planetesimals and, possibly, the water contents of planets. Many hypotheses have been proposed for the origin of ²⁶Al in the solar system. One of the possible hypotheses is the `disk injection scenario'; when the protoplanetary disk of the solar system had already formed, a nearby (<1pc) supernova injected radioactive material directly into the disk. Such a ²⁶Al injection hypothesis has been tested so far with limited setups for disk structure and supernova distance and treated disk disruption and ²⁶Al injection separately. Here, we revisit this problem to investigate whether there are self-consistent conditions under which the surviving disk radius can receive enough ²⁶Al which can account for the abundance in the early solar system. We also consider a range of disk mass and structure, ²⁶Al yields from supernova, and a large dust mass fraction ηd. We find that ²⁶Al yields of supernova are required as >2.1×10⁻³M(η_d/0.2)⁻¹, challenging to achieve with known possible ²⁶Al ejection and dust mass fraction ranges. Furthermore, we find that even if the above conditions are met, the supernova flow changes the disk temperature, which may not be consistent with the solar-system record. Our results place a strong constraint on the disk injection scenario. Rather, we suggest that the fresh ²⁶Al of the early solar system must have been synthesized/injected in other ways.

Ref.) Sawada et al. 2024 in press. https://arxiv.org/abs/2312.01948