Large-area [Fe II] Line Mapping of the Supernova Remnant IC443 with the IRSF/SIRIUS

TL;DR

This study maps near-infrared [Fe II] emission across the supernova remnant IC443, revealing filamentary structures and enhanced emission in the central region, providing insights into dust and iron distribution.

Contribution

First large-area [Fe II] line mapping of IC443 covering 30' x 35', showing filamentary structures in various shock regions and analyzing dust extinction effects.

Findings

[Fe II] filaments are widespread across IC443.

Enhanced [Fe II] emission observed in the remnant's central region.

Estimated Fe+ and dust masses from emission data.

Abstract

We present the result of near-infrared (near-IR) [Fe II] line mapping of the supernova remnant IC443 with the IRSF/SIRIUS, using the two narrow-band filters tuned for the [Fe II] 1.257 micron and [Fe II] 1.644 micron lines. Covering a large area of 30' x 35', our observations reveal that [Fe II] filamentary structures exist all over the remnant, not only in an ionic shock shell, but also in a molecular shock shell and a central region inside the shells. With the two [Fe II] lines, we performed corrections for dust extinction to derive the intrinsic line intensities. We also obtained the intensities of thermal emission from the warm dust associated with IC443, using the far- and mid-IR images taken with AKARI and Spitzer, respectively. As a result, we find that the [Fe II] line emission relative to the dust emission notably enhances in the inner central region. We discuss causes of the enhanced [Fe II] line emission, estimating the Fe+ and dust masses.