DUST DESTRUCTION IN A NON-RADIATIVE SHOCK IN THE CYGNUS LOOP SUPERNOVA REMNANT

作者：Sankrit Ravi^*; Williams Brian J; Borkowski Kazimierz J; Gaetz Terrance J; Raymond John C; Blair William P; Ghavamian Parviz; Long Knox S; Reynolds Stephen P

来源：Astrophysical Journal, 2010, 712(2): 1092-1099.

DOI：10.1088/0004-637X/712/2/1092

• dust, extinction
• ISM: individual objects (Cygnus Loop)
• ISM: supernova remnants
• shock waves

We present 24 mu m and 70 mu m images of a non-radiative shock in the Cygnus Loop supernova remnant, obtained with the Multiband Imaging Photometer for Spitzer on board the Spitzer Space Telescope. The post-shock region is resolved in these images. The ratio of the 70 mu m to the 24 mu m flux rises from about 14 at a distance 0.'1 behind the shock front to about 22 in a zone 0.'75 further downstream, as grains are destroyed in the hot plasma. Models of dust emission and destruction using post-shock electron temperatures between 0.15 keV and 0.30 keV and post-shock densities, n(H) similar to 2.0 cm(-3), predict flux ratios that match the observations. Non-thermal sputtering (i.e., sputtering due to bulk motion of the grains relative to the gas) contributes significantly to the dust destruction under these shock conditions. From the model calculations, we infer that about 35% by mass of the grains are destroyed over a 0.14 pc region behind the shock front.

• 出版日期2010-4-1