Inner Size of a Dust Torus in the Seyfert 1 Galaxy NGC 4151
Inner Size of a Dust Torus in the Seyfert 1 Galaxy NGC 4151
复制标题
DOI：
10.1086/381364
复制
发表时间：
2003-11
期刊：
影响因子：
--
通讯作者：
T. Minezaki;Y. Yoshii;Yukiyasu Kobayashi;K. Enya;M. Suganuma;H. Tomita;T. Aoki;B. Peterson
中科院分区：
文献类型：
--
作者：
T. Minezaki;Y. Yoshii;Yukiyasu Kobayashi;K. Enya;M. Suganuma;H. Tomita;T. Aoki;B. Peterson
在光学和近红外波段对塞弗特1星系NGC 4151进行了迄今为止最密集的监测观测。测量了光学光曲线到近红外光曲线的滞后。在2001年通量最小时，V光曲线和K光曲线之间的滞后时间恰好是48天。结合以往对NGC 4151和其他AGN的滞后时间测量，给出了NGC 4151活动星系核（AGN）的光学光度与紫外/光学曲线和近红外光曲线之间的滞后时间之间的相关性。这种相关性被解释为AGN中的热尘埃混响，其中AGN的近红外辐射预计是中心发动机周围热尘埃的热辐射，其半径温度等于尘埃升华温度。我们发现NGC 4151中尘埃环的内半径为0.04 pc，与测量的滞后时间相对应，远远超出了其他发射谱线混响研究确定的宽线区域。
The most intense monitoring observations yet made were carried out on the Seyfert 1 galaxy NGC 4151 in the optical and near-infrared wave bands. A lag from the optical light curve to the near-infrared light curve was measured. The lag time between the V and K light curves at the flux minimum in 2001 was precisely 48 days, as determined by a cross-correlation analysis. The correlation between the optical luminosity of an active galactic nucleus (AGN) and the lag time between the UV/optical and the near-infrared light curves is presented for NGC 4151 in combination with previous lag-time measurements of NGC 4151 and other AGNs in the literature. This correlation is interpreted as thermal dust reverberation in an AGN, where the near-infrared emission from an AGN is expected to be the thermal reradiation from hot dust surrounding the central engine at a radius where the temperature equals that of the dust sublimation temperature. We find that the inner radius of the dust torus in NGC 4151 is ~0.04 pc corresponding to the measured lag time, well outside the broad-line region determined by other reverberation studies of the emission lines.