Study On Polarized Radiation Of Active Galactic Nucleus

Supermassive black holes are located in the center of most massive galaxies.The difference between active and static galaxies is the difference of mass absorptivity and emissivity.They are different,not whether they have black hole galactic nuclei.This paper mainly introduces the AP15 method to measure the mass of supermassive black holes,which is currently only suitable for Seyfert galaxy,especially for Seyfert I galaxy.In this paper,9 AGNs(Seyfert Galaxy)polarizations are observed,of which NGC 4051,NGC 4151,3C 273 and PG 0844 + 349 are mainly discussed.It is found that the mass measured by this method is very consistent with that measured by the reverse mapping method.It is also found that the estimated values of NGC 4051,NGC 4151,3C 273 and PG 0844 + 349 are in good agreement with the observed values.We use Stokes radiation transfer code,and mainly use pure Kepler motion,Kepler+radial-inflow and Kepler+vertical-outflow to explore the possibility and limitations of this method in the wide line region(BLR).Our model simulation shows that the AP15 method can be widely used in type-1 AGN when the viewing angle is between 25° and 45°.The distance between the broad line region and the scattering region(Torus)has a significant effect on the quality estimation.The simulation results show that the best mass estimation is that the radius of scattering region is 1.5-2.5 times larger than that of BLR.When there is radial inflow or vertical outflow in BLR,if the velocity of inflow/outflow is less than 500km/s,AP15 method can still be used.The model simulation shows that the AP15 method can be widely used in AGN of type-1 when the viewing angle is between 25° and 45°.The distance between the wide line region and the scattering region(torus)has a significant effect on the quality estimation.The simulation results show that the best mass estimation is when the radius of scattering region is 1.5--2.5 times larger than that of BLR.When there is radial internal flow or vertical external flow in BLR,if the velocity of inflow/outflow is less than 500km/s,AP15 method can still be used.The influence of NLR on the polarization of optical/UV continuous spectrum is also discussed.In order to solve the problem of continuous scattering and absorption in NLR,a dust epitaxy with low light depth is added to the outflow.The model simulation shows that NLR can change or suppress polarization dichotomy observed between AGNs of type-1 and type-2.For type-2 AGN,it will also significantly reduce the degree of polarization we predicted and change the shape of its polarization spectrum.Based on the polarization data of 22 blazars in UMRAO database and the theoretical model of lazarian & pogosyan,this paper also analyzes and studies the change of the polarization of the radio band with the wavelength,and obtains the reasons for the change of the polarization with the wavelength of different types of Yao.The results show that it is in good agreement with the theoretical model of lazarian & pogosyan.The conclusions are as follows:(1)the anomalous Faraday rotation plays a leading role in the anomalous depolarization variation source,and the anomalous depolarization is relatively small;(2)the polarization of the high frequency band is less than that of the low frequency band(anomalous depolarization)due to the mixing effect of thermal radiation and synchrotron radiation;(3)when the wavelength of the observed band is less than that of the Wien wavelength corresponding to the thermal radiation of the accretion disk The polarization degree of high frequency band is higher than that of low frequency band(conventional depolarization).