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Paper: |
Excess Submillimeter Emission in the Starburst Galaxy NGC 3310? |
Volume: |
446, Galaxy Evolution: Infrared to Millimeter Wavelength Perspective |
Page: |
119 |
Authors: |
Zhu, M.; Papadopoulos, P. P.; Xilouris, M.; Kuno, N.; Lisenfeld, U. |
Abstract: |
We present a new observational study of the gas and dust properties
in the starburst galaxy NGC 3310, whose bulk interstellar medium
(ISM) resides in environments that mark (and bracket) the excitation
extremes of the ISM conditions found in infrared luminous galaxies
(Zhu et al. 2009). One of our major findings is that the dust
emission spectrum in NGC 3310 shows a pronounced submillimeter
“excess”. We tried to fit this excess by a cold dust component
but very low temperatures were required (Tc ∼ 5-11 K) with a
correspondingly low gas-to-dust mass ratio of 5-43. We furthermore
show that it is not possible to maintain the large quantities of
dust required at these low temperatures in this starburst galaxy.
Instead, we conclude that the dust properties need to be different
from Galactic dust in order to fit the submillimeter “excess”. We
show that the dust spectral energy distribution can be fitted by an
enhanced abundance of very small grains and discuss different
alternatives. |
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