Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 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.

15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg