OPTICAL AND NEAR-INFRARED POLARIMETRY OF HIGHLY REDDENED Type Ia SUPERNOVA 2014J: PECULIAR PROPERTIES OF DUST IN M82

Abstract

We presented optical and near-infrared multi-band linear polarimetry of the\nhighly reddened Type Ia SN~2014J appeared in M82. SN~2014J exhibits large\npolarization at shorter wavelengths, e.g., $4.8$\\% in $B$ band, and the\npolarization decreases rapidly at longer wavelengths, with the position angle\nof the polarization remaining at approximately $40^{\\circ}$ over the observed\nwavelength range. These polarimetric properties suggest that the observed\npolarization is likely to be caused predominantly by the interstellar dust\nwithin M82. Further analysis shows that the polarization peaks at a wavelengths\nmuch shorter than those obtained for the Galactic dust. The wavelength\ndependence of the polarization can be better described by an inverse power law\nrather than by Serkowski law for Galactic interstellar polarization. These\nsuggests that the nature of the dust in M82 may be different from that in our\nGalaxy, with polarizing dust grains having a mean radius of $<0.1\\ \\mu$m.\n