Origin of the dust emission from Tycho's SNR

TL;DR

This study uses infrared imaging to analyze the spatial distribution of dust around Tycho's SNR, distinguishing between dust from the supernova remnant and the surrounding interstellar medium, revealing shell-like structures and potential ejecta dust.

Contribution

It provides detailed infrared observations and analysis to identify the origin of dust emission in Tycho's SNR, highlighting the interaction with ambient clouds and the possibility of ejecta dust.

Findings

Shell-like dust emission correlates with X-ray shell structure.

Dust at NE boundary originates from ambient cloud interaction.

NW boundary dust origin remains uncertain, possibly ejecta.

Abstract

Aims: We investigate the spatial distribution of dust emission around Tycho's SNR to understand its origin. We distinguish the dust associated with the SNR from that of the surrounding ISM. Methods: We performed mid- to far-infrared imaging observations of the remnant at wavelengths of 9, 15, 18, 24, 65, 90, 140, and 160um using the Infrared Camera and the Far-Infrared Surveyor onboard AKARI. We compared the AKARI images with the Suzaku X-ray image and the 12CO image of Tycho's SNR. Results: All the AKARI images except the 9, 140, and 160um band images show a shell-like emission structure with brightness peaks at the north east (NE) and north west (NW) boundaries, sharply outlining part of the X-ray shell. The 140 and 160um bands are dominated by cold dust emission from the surrounding ISM near the NE boundary. Conclusion: We conclude that the dust emission at the NE boundary comes from the ambient cloud interacting with the shock front, while the origin of the dust emission at the NW boundary is rather unclear because of the absence of prominent interstellar clouds near the corresponding region. We cannot rule out the possibility that the latter is mostly of an SN ejecta origin.