Late-time cosmic evolution of dust: solving the puzzle

TL;DR

This study explains the observed decline in cosmic dust mass density from redshift 1 to 0 by identifying dominant destruction mechanisms, notably astration and supernova shocks, and revises the estimated dust destruction per supernova.

Contribution

It introduces a new model quantifying dust destruction processes over cosmic time and revises the supernova dust destruction estimate to be significantly lower than previous assumptions.

Findings

Dust destruction mainly due to astration and supernova shocks.

Supernovae destroy about 0.45 solar masses of dust, lower than prior estimates.

Upper limit of dust destroyed per supernova is 3.0 solar masses.

Abstract

Dust is an essential ingredient of galaxies, determining the physical and chemical conditions in the interstellar medium. Several complementary observational evidences indicate that the cosmic dust mass density significantly drops from redshift $z=1$ to $z=0$. Clearly, and for the first time during cosmic evolution, dust must be destroyed more rapidly than it is formed. By considering the dust production/destruction processes acting in this cosmic time lapse, we find that the drop can be explained if dust is mainly destroyed by astration (49\% contribution in the fiducial case) and supernova shocks within galaxies (42\%). Our results further imply that on average each supernova destroys only $M_{d,sn} =0.45\, M_\odot$ of dust, i.e. $5-10$ times less than usually assumed, with a hard upper limit of $M_{d,sn} < {3.0} M_\odot$ set by the available metal budget and maximal grain growth. The lower efficiency might be explained by effective shielding of dust against shock processing in pre-supernova wind shells.