arXiv subjects

XueGuang Zhang

Publications and source records attributed to XueGuang Zhang.

39 records · Page 3Linked to original sources

arXiv2013

More Evidence for the Intermediate Broad Line Region of the Mapped AGN PG 0052+251

In the manuscript, the properties of the proposed intermediate BLR are checked for the mapped AGN PG 0052+251. With the considerations of the apparent effects of the broad He {\sc ii} line on the observed broad H$β$ profile, the line parameters (especially the line width and the line flux) of the observed broad H$α$ and the broad H$β$ are carefully determined. Based on the measured line parameters, the model with two broad components applied for each observed broad balmer line is preferred, and then confirmed by the calculated much different time lags for the inner/intermediate broad components and the corresponding virial BH masses ratio determined by the properties of the inner and the intermediate broad components. Then, the correlation between the broad line width and the broad line flux is checked for the two broad components: one clearly strong negative correlation for the inner broad component, but one positive correlation for the intermediate broad component. The different correlations for the two broad components strongly support the intermediate BLR of PG0052+251.

astro-ph.CO↗

arXiv2013

Further Evidence for the Accretion Disk Origination of the Double-Peaked Broad H$α$ of 3C390.3

In the letter, under the widely accepted theoretical accretion disk model for the double-peaked emitter 3C390.3, the extended disk-like BLR can be well split into ten rings, and then the time lags between the lines from the rings and the continuum emission are estimated, based on the observed spectra around 1995. We can find one much strong correlation between the determined time lags (in unit of light-day) and the flux weighted radii (in unit of ${\rm R_G}$) of the rings, which is well consistent with the expected results through the theoretical accretion disk model. Moreover, through the strong correlation, the black hole masses of 3C390.3 are independently estimated as $\sim10^9{\rm M_{\odot}}$, the same as the reported black hole masses in the literature. The consistencies provide further evidence to strongly support the accretion disk origination of the double-peaked broad balmer lines of 3C390.3.

astro-ph.CO↗

arXiv2012

Correlation between Line Width and Line Flux of Double-Peaked Broad Halpha of 3C390.3

In this manuscript, we carefully check the correlation between the line width and the line flux of the double-peaked broad H$α$ of the well-known mapped AGN 3C390.3, in order to show some further distinctions between double-peaked emitters and normal broad line AGN. Based on the Virialization assumption and the empirical relation about $R_{BLR}$, one strong negative correlation of line parameters of the double-peaked broad lines should be expected for 3C390.3, such as the negative correlation confirmed for the mapped broad line object NGC5548. But, based on the public spectra around 1995 from the AGNWATCH project for 3C390.3, one reliable positive correlation is found. In the context of the proposed theoretical accretion disk model for double-peaked emitters, the unexpected positive correlation can be naturally explained, due to different time delays for inner parts and outer parts of disk-like BLR of 3C390.3. Moreover, the Virialization assumption is checked and found to be still available for 3C390.3. However, time-varying size of the BLR of 3C390.3 can not be expected by the empirical relation $R_{BLR}\propto L^{\sim0.5}$, the continuum emission strengthening leads to the size of BLR decreasing (not increasing) in different moments for 3C390.3. Then, we compared our results of 3C390.3 with the previous results reported in the literature for the other double-peaked emitters, and found that before to clearly correct effects from disk physical parameters varying for long-term observed line spectra and effects from the probable 'external' ionizing source with so far unclear structures, it is hard to give one conclusion that the positive correlation can be found for all double-peaked emitters. However, once one positive correlation of broad line parameters was found, the accretion disk origination of the broad line should be firstly considered.

astro-ph.CO↗