A unique X-ray unabsorbed Seyfert 2 galaxy IRAS F01475-0740

X-ray unabsorbed Seyfert 2 galaxies appear to have X-ray absorption column densities that are too low (NH < 10^22 cm-2) to explain the absence of broad emission lines in their optical spectra, challenging the standard AGN unification model. In this paper we report Suzaku exposure on the X-ray unabsorbed Seyfert 2 galaxy IRAS F01475-0740, in which a hidden broad line region was detected through spectropolarimetric observation. The X-ray data show rapid and significant variations on time scales down to 5 ks, indicating that we are viewing its central engine directly. A newly obtained optical spectrum and previous optical/X-ray data suggest that state transition is unlikely in this source. These make IRAS F01475-0740 a very peculiar X-ray unabsorbed Seyfert 2 galaxy which can only be explained by absorption from materials with abnormally high dust-to-gas ratio (by a factor of > 4 larger than Galactic). This is in contrast to most AGNs, which typically show dust-to-gas ratios 3 - 100 times lower than the Galactic.Comment: 13 pages, 3 figures, 1 table, accepted to the Astrophysical Journal Letter

Phase Reversal Diffraction in incoherent light

Phase reversal occurs in the propagation of an electromagnetic wave in a negatively refracting medium or a phase-conjugate interface. Here we report the experimental observation of phase reversal diffraction without the above devices. Our experimental results and theoretical analysis demonstrate that phase reversal diffraction can be formed through the first-order field correlation of chaotic light. The experimental realization is similar to phase reversal behavior in negatively refracting media.Comment: 8 pages, 5 figure