your ID: 0313 
First Name: Enpeng 
Last Name: Zhang 
Affiliation: Institute ohf High Energy Physics, CAS, China

 Title: Non-Hidden Broad Line Region Syfert 2s and the Unified Model of AGN 
Authors: Enpeng Zhang & Jianmin Wang 
Topic: 6 
Session: poster 

Abstract:  
The unified model of Seyfert galaxies suggests that there are 
hidden broad-line regions (HBLRs) in Seyfert 2 galaxies (S2s). However, 
there is increasing evidence for the appearance of a subclass of  S2s lacking 
of HBLR (non-HBLR S2s). An interesting issue arises as to relations of 
non-HBLR S2s with other types of Seyfert galaxies and whether or not they 
can be included in the unified model. We assemble two sub-sample consisting 
of 42 non-HBLR S2s and 44 narrow-line Seyfert 1s (NLS1s) with redshift 
$z\\le 0.05$ from published literatures to explore this issue. We compare black
hole masses in the galactic centers, accretion rates, infrared color ratio 
($f_{60 \\mu \\rm m}/f_{25 \\mu \\rm m}$) as a potential indicator of the
 dusty torus orientation, [O III] $\\lambda 5007$, radio and far infrared luminosities. 
We find that non-HBLR S2s and NLS1s have: 1) similar distributions of the black 
hole masses ($10^6-3\\times 10^7\\sunm$) and the Eddington ratios
 ($L_{\\rm Bol}/L_{\\rm Edd}\\sim 1$); 2) significantly different distributions 
of $f_{60 \\mu \\rm m}/f_{25 \\mu \\rm m}$ ratio; 3) similar luminosity  distributions 
of [O III], radio, far infrared. The similarities and differences can be 
understood naturally  if they are intrinsically same but non-HBLR S2s are viewed at 
larger angles of sight than NLS1s. We thus suggest that non-HBLR S2s are the 
counterparts of NLS1s viewed at high inclination angles. The absence of the polarized
 emission line in non-HBLR S2s is caused by the less massive black hole and high 
accretion rate similar to NLS1s. The implications of the unification scheme of 
non-HBLR S2s and NLS1s are discussed.