A dust twin of Cas A: 21-micron dust feature in the Supernova remnant G54.1+0.3

We present Spitzer and submm observations of a Crab-like supernova remnant, G54.1+0.3. We serendipitously discovered a dust feature peaking at 21 micron from G54.1+0.3, and the 21-micron dust is remarkably similar to that of Cas A from Rho et al. (2008). The IRS spectrum from the western shell shows the 21-micron dust feature and strong [Ar II] and weak [Ne II], [S III] and [Si II] lines. Strong correlation between 21-micron dust and Ar ejecta has been observed in Cas A. IRAC 8-micron emission mostly from Ar ejecta shows shell-like morphology and MIPS 24 and 70 micron emission from continuum also show shell-like morphology, suggesting that dust has been formed in ejecta. The shell-like ejecta distribution around pulsar wind nebula is analogy with that of the Crab Nebula. We detected submm emission from G54.1+0.3 using SHARCII (at 350 micron) and LABOCA (at 870 micron). We present dust fitting using continuous distributions of ellipsoidal (CDE) grain models. Spectral fitting requires a combination of dust composition including SiO2, SiC, and Al2O3 which are responsible for 21-micron, 11 micron dust features and long-wavelength continuum, respectively. We will discuss dust properties and inferred dust mass from G54.1+0.3 and implication of supernova-dust production in early Universe. I also show how SOFIA (Stratospheric Observatory for Infrared Astronomy) can help in study-ing supernova remnants at mid-and far-infrared and submm.