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arXiv · 1103.0607

Far-infrared emission from intergalactic medium in Stephan's Quintet revealed by AKARI

Toyoaki Suzuki·Hidehiro Kaneda·Takashi Onaka·Tetsu Kitayama
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Abstract

The Stephan's Quintet (SQ, HCG92) was observed with the Far-Infrared Surveyor (FIS) aboard AKARI in four far-infrared (IR) bands at 65, 90, 140, and 160 um. The AKARI four-band images of the SQ show far-IR emission in the intergalactic medium (IGM) of the SQ. In particular, the 160 um band image shows single peak emission in addition to the structure extending in the North-South direction along the shock ridge as seen in the 140 um band, H2 emission and X-ray emission. Whereas most of the far-IR emission in the shocked region comes from the cold dust component, shock-powered [CII]158um emission can significantly contribute to the emission in the 160 um band that shows a single peak at the shocked region. In the shocked region, the observed gas-to-dust mass ratio is in agreement with the Galactic one. The color temperature of the cold dust component (~20 K) is lower than that in surrounding galaxies (~30 K). We discuss a possible origin of the intergalactic dust emission.

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Toyoaki Suzuki, Hidehiro Kaneda, Takashi Onaka, Tetsu Kitayama. 2011-03-03. Far-infrared emission from intergalactic medium in Stephan's Quintet revealed by AKARI. https://doi.org/10.1088/2041-8205%2F731%2F1%2Fl12

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