Po-Sheng Ou (ASIAA/NTU); You-Hua Chu (ASIAA); Ping Zhou (University of Amsterdam); Oliver Porth (University of Amsterdam)
Core-collapse supernovae (CCSNe) are thought to be the main source of dust production in the early universe; however, the predicted amount of SN ejecta dust had not been detected until last decade, and the mechanism of SN dust formation is still poorly understood. SNR 0540-69.3 is the second youngest supernova remnant (SNR) in the Large Magellanic Cloud (LMC), older than only SN1987A, and it is often called a “twin” of the Crab nebula because of its pulsar wind nebula (PWN). Spitzer and Herschel fluxes of SNR 0540-69.3 indicate the presence of dust emission at the center of this SNR, but their angular resolutions are insufficient to resolve the dust clumps and PWN structures. To investigate the dust content and to resolve it from the PWN, we obtained a high-resolution ALMA Band 3 (100 GHz) observation of the PWN, and compared it with Chandra, HST, Spitzer, and ATCA images. The ALMA image shows extended filaments, and also several bright clumps around the projected position of the pulsar. These structures are resolved for the first time! We suggest that the bright clumps are likely cold dust formed in dense SN ejecta. We also discuss scenarios to have these dense clumps remain at the very central region of the PWN and form fresh dust. This discovery provides new insights into the formation of dust within young SNRs.