Galactic dust budgets: the role of dust produced in core-collapse supernovae

Astronomy Unit Seminars
Ilse de Looze
Izaskun Jimenez-Serra
October 20th, 2017 at 14:30
GO Jones Room 610

The large reservoirs of dust observed in some high redshift galaxies have been hypothesised to originate from dust produced by supernovae from massive stars. Theoretical models predict that core-collapse supernovae (CCSN) can be efficient dust producers (0.1-1 Msun) potentially responsible for most of the dust production in the early Universe. Observational evidence for this dust production efficiency is however currently limited to only a few CCSN remnants (e.g., SN 1987A, Crab Nebula) that confirm this scenario. 

In this talk, I will revisit the dust mass produced in Cassiopeia A (Cas A), a 330-year old O-rich Galactic supernova remnant (SNR) embedded in a dense interstellar foreground and background, and present the first spatially resolved analysis of Cas A based on Spitzer and Herschel data. From this analysis, we were able to locate a concentration of cold dust in the unshocked ejecta of Cas A and derive a mass of 0.3-0.6 Msun of silicate grains freshly produced in the SNR. These dust masses estimates are higher than from most previous studies of Cas A and support the scenario of supernova dominated dust production at high redshifts. Our resolved analysis shows that the cold SN dust component is mainly distributed interior to the reverse shock of Cas A, suggesting that part of the newly formed dust has already been destroyed by the reverse shock. 

I will also discuss the results that we obtained for the Galactic supernova remnant Cas A, in light of other ongoing studies of dust production in supernova remnants to address the question whether supernovae can be responsible for most of the dust production in the early and present-day Universe.