# Dust grains from the heart of supernovae

**Authors:** M. Bocchio, S. Marassi, R. Schneider, S. Bianchi, M. Limongi, A. Chieffi  
**arXiv:** [1601.06770](https://arxiv.org/abs/1601.06770)  
**Date:** 2016-01-25  
**Summary page:** https://www.summarizepaper.com/en/paper/1601.06770v1/

## Key points

- Dust grains are believed to form in the winds of AGB stars and supernovae (SNe).
- To determine the importance of these two sources, it is crucial to understand how much freshly formed dust in SN ejecta can survive the passage of the reverse shock and be injected into the interstellar medium.
- A team led by M. Bocchio developed a new code called GRASH_Rev that allows for tracking the dynamics of dust grains in shocked SN ejecta and computing their time evolution with respect to mass, composition, and size distribution.
- The team studied four well-known SNe in the Milky Way and LMC: SN 1987a, Cas A, Crab Nebula, and N49. They found good agreement between their simulated models and observations.
- Between 10% and 40% of initial dust mass has already been destroyed by the reverse shock in three SNe studied.
- The largest destruction will occur between 10^3 and 10^5 years after explosions.
- Only between 1% and 8% of currently observed mass will survive due to age limitations.
- Understanding how much dust survives from newly formed SNe is essential for accurately predicting galactic evolution over cosmic time scales.

## Summary

Dust grains have long been believed to form in the winds of AGB (asymptotic giant branch) stars, but recent evidence suggests that they may also form in supernovae (SNe). To determine the relative importance of these two sources of dust, it is crucial to understand what fraction of freshly formed dust in SN ejecta can survive the passage of the reverse shock and be injected into the interstellar medium. To address this question, a team led by M. Bocchio developed a new code called GRASH_Rev that allows for tracking the dynamics of dust grains in shocked SN ejecta and computing their time evolution with respect to mass, composition, and size distribution. The team studied four well-known SNe in the Milky Way and LMC: SN 1987a, Cas A, Crab Nebula, and N49. They found good agreement between their simulated models and observations. Their study showed that while SN 1987A is too young for its reverse shock to have affected its dust mass, between 10% and 40% of initial dust mass has already been destroyed by the reverse shock in the other three SNe. However, they predict that the largest destruction will occur between 10^3 and 10^5 years after explosions. Since current observations can only provide an upper limit on effective dust yields due to age limitations (the oldest SN in their sample has an estimated age of 4800 years), they found that only between 1% and 8% of currently observed mass will survive. This result agrees with values adopted in chemical evolution models that consider the effect of SN reverse shocks. The team discussed astrophysical implications for dust enrichment both locally and at high redshifts based on their findings. They concluded that understanding how much dust survives from newly formed SNe is essential for accurately predicting galactic evolution over cosmic time scales.