WIDE INTEGRAL-FIELD INFRARED SPECTROSCOPY OF THE BRIGHT [Fe II] SHELL IN THE YOUNG SUPERNOVA REMNANT G11.2–0.3

Abstract

We present the results of wide integral-field near-infrared (1.0-1.8 µm) spectroscopic observations of the southeastern shell of the young core-collapse supernova remnant (SNR) G11.2−0.3. We first construct [Fe II] 1.644 µm line images of three bright clumps from the obtained spectral image cubes and compare them with those of other transitions such as [Fe II] 1.257, [Fe II] 1.534 and He I 1.083 µm line images. This allows us to estimate the electron density (∼ 4,700-9,400 cm −3 ) and extinction (A V ∼ 16-20 mag) of the shell, including detailed two-dimensional distribution of the properties in the brightest clump, as well as the discovery of a faint high-velocity (∼ -440 km s −1 ) component in the clump. Our SNR shock model calculations estimate the preshock number density of ∼ 250-500 cm −3 and shock speed of ∼ 80-250 km s −1 in the [Fe II]-emitting region of the SNR. The comparison between the observed and modelled radial profiles of the line intensities and their ratios reveals that the shell is composed of multiple thin filaments which have been likely formed in episodic mass loss processes of a progenitor star. The discovery of the faint high-velocity component supports the interpretation that the southeastern shell of G11.2−0.3 is mainly composed of circumstellar material with contamination by supernova ejecta and also that its ejected material was expelled primarily in the southeast-northwest direction. Subject headings: ISM: individual objects (G11.2−0.3) -ISM: supernova remnants -infrared: ISM -shock waves

UKIRT Widefield Infrared Survey for Fe+

“…Along with this front shock expanding into the surrounding medium, there exists a reverse shock which propagates back into SN material. Strong NIR [Fe II] lines are emitted when these shocks interact with dense material, which could be either the SN or the circumstellar material for young SNRs, and usually interstellar material for middle-aged SNRs (e.g., Oliva et al 1989Oliva et al , 1990Koo et al 2007;Lee et al 2009;Moon et al 2009;Lee et al 2013, see also Koo 2013 and references therein). Moreover, Fe, being the end product of the stellar nucleosynthesis process, forms a main component of the supernova ejecta; the materials ejected from the deep layers of the progenitor are often enriched in Fe.…”

The uGMRT observations of three new GPS pulsars

“…• n e ∼ a few thousand cm −3 for T e ∼ 5000 K in case of a dense supernovae filament (see e.g. Lee et al 2013);…”

Near-Infrared Spectroscopy of Young Galactic Supernova Remnants

“…More recently, it was found that the NIR spectra of young SNRs are interesting, sometimes showing many ionic lines from supernova (SN) ejecta material (Gerardy & Fesen, 2001;Koo et al, 2007;Moon et al, 2009;Lee et al, 2013;Koo et al, 2013). In the Milky Way, there are about 300 SNRs, and 20-30 of them are younger than several thousand years.…”