56,848 research outputs found

    Relation of SiO maser emission to IR radiation in evolved stars based on the MSX observation

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    Based on the space MSX observation in bands A(8μ\mum), C(12μ\mum), D(15μ\mum) and E(21μ\mum), and the ground SiO maser observation of evolved stars by the Nobeyama 45-m telescope in the v=1 and v=2 J=1-0 transitions, the relation between SiO maser emission and mid-IR continuum radiation is analyzed. The relation between SiO maser emission and the IR radiation in the MSX bands A, C, D and E is all clearly correlated. The SiO maser emission can be explained by a radiative pumping mechanism according to its correlation with infrared radiation in the MSX band A.Comment: 11 pages, 4 figures, to appear in ApJ

    Dust in the Local Group

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    How dust absorbs and scatters starlight as a function of wavelength (known as the interstellar extinction curve) is crucial for correcting for the effects of dust extinction in inferring the true luminosity and colors of reddened astrophysical objects. Together with the extinction spectral features, the extinction curve contains important information about the dust size distribution and composition. This review summarizes our current knowledge of the dust extinction of the Milky Way, three Local Group galaxies (i.e., the Small and Large Magellanic Clouds, and M31), and galaxies beyond the Local Group.Comment: 21 pages, 11 figures; invited review article published in "LESSONS FROM THE LOCAL GROUP -- A Conference in Honour of David Block and Bruce Elmegreen" eds. Freeman, K.C., Elmegreen, B.G., Block, D.L. & Woolway, M. (SPRINGER: NEW YORK), pp. 85-10
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