Properties and alignment of interstellar dust grains toward Type Ia
  Supernovae with anomalous polarization curves
  Recent photometric and polarimetric observations of type Ia supernovae (SNe
Ia) show unusually low total-to-selective extinction ratio ($R_{V}<2$) and
wavelength of maximum polarization ($\lambda_{max}<0.4\mu m$) for several SNe
Ia, which indicates peculiar properties of interstellar (IS) dust in the SN
hosted galaxies and/or the presence of circumstellar (CS) dust. In this paper,
we use inversion technique to infer best-fit grain size distribution and
alignment function of interstellar grains along the lines of sight toward four
SNe Ia with anomalous extinction and polarization data (SNe 1986G, 2006X,
2008fp, and 2014J). We find that to reproduce low values of $R_{V}$, a
significant enhancement in the mass of small grains of radius $a< 0.1\mu m$ is
required. For SN 2014J, a simultaneous fit to observed extinction and
polarization data is unsuccessful if the entire data is attributed to IS dust
(model 1), but a good fit is obtained when accounting for the contribution of
CS dust (model 2). For SN 2008fp, our fitting results for model 1 show that, to
reproduce an extreme value of $\lambda_{\max}\sim 0.15\mu m$, very small
silicate grains must be aligned as efficiently as big grains. We suggest that
tiny grains in the intervening molecular cloud can be aligned efficiently by
radiative torques (RATs) from the SNe Ia. The resulting time dependence
polarization from this RAT alignment model can be tested by observing at
ultraviolet wavelengths. Our results are in favor of the existence of CS dust
in SN 2014J, but its presence in SN 2008fp remains uncertain.
