论文标题
低红移主动银河系核的中红外变异性：具有可变覆盖因子的热灰尘成分的约束
Mid-infrared Variability of Low-redshift Active Galactic Nuclei : Constraints on a Hot Dust Component with a Variable Covering Factor
论文作者
论文摘要
We utilize mid-infrared multi-epoch data from Wide-field Infrared Survey Explorer (WISE) over a $\sim10$-year period in W1 (3.4$μ$m) and W2 (4.6$μ$m) bands to investigate the structure of dusty torus in low-redshift ($0.15<z\le 0.4$) active galactic nuclei (AGN).我们根据单个对象的光曲线计算了W1幅度和W1 $ - $ W2颜色之间的Spearman相关系数（$ r_ {12} $）。有趣的是，$ r_ {12} $跨越范围从$ -1 $到$ 1 $，并且被发现与平均W1 $ - $ W2 $ - $ W2颜色和AGN侧重测光相关，从某种意义上说，在蓝色W1 $ - $ W1 $ - $ W2颜色和低agn亮度的对象中，与REDDER（BLUER）相关（bluer）趋向于（降低）。 $ r_ {12} <0 $），尽管$ r_ {12} $与降压光度的相关性相对较弱。光谱能量分布的拟合表明，W1和W2波段中宿主星系的显着贡献。但是，即使在仔细消除主机光贡献之后，W1 $ - $ W2颜色和AGN光度的$ r_ {12} $的依赖项仍然持续存在。我们建议，如果随着AGN光度的增加，热灰尘成分的覆盖因子降低，则可以解释这一结果。
We utilize mid-infrared multi-epoch data from Wide-field Infrared Survey Explorer (WISE) over a $\sim10$-year period in W1 (3.4$μ$m) and W2 (4.6$μ$m) bands to investigate the structure of dusty torus in low-redshift ($0.15<z\le 0.4$) active galactic nuclei (AGN). We calculate a Spearman correlation coefficient ($r_{12}$) between W1 magnitude and W1$-$W2 color based on the light curve in individual objects. Interestingly, $r_{12}$ spans a broad range from $-1$ to $1$, and is detected to be correlated with mean W1$-$W2 color and AGN bolometric luminosity, in the sense that objects with blue W1$-$W2 color and low AGN luminosity tend to become redder (bluer) with increasing (decreasing) W1 brightness in the light curve (i.e. $r_{12} < 0$), although the correlation of $r_{12}$ with the bolometric luminosity is relatively weak. The fit for the spectral energy distribution reveals a significant contribution from the host galaxy in the W1 and W2 bands. However, the dependencies of $r_{12}$ on W1$-$W2 color and AGN luminosity still persist even after careful elimination of the host light contribution. We propose that this result can be explained if covering factor of the hot dust component decreases as AGN luminosity increases.
