THE STRUCTURE OF THE ACCRETION DISK IN THE LENSED QUASAR SBS 0909+532
THE STRUCTURE OF THE ACCRETION DISK IN THE LENSED QUASAR SBS 0909+532
复制标题
透镜类星体中吸积盘的结构 SBS 0909 532
DOI：
10.1088/0004-637x/730/1/16
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
A. Mosquera
中科院分区：
文献类型：
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作者：
E. Mediavilla;J. A. Muñoz;C. S. Kochanek;E. Guerras;J. Acosta;E. Falco;Verónica Motta;Santiago Arribas;A. Manchado;A. Mosquera
通过测量透镜星系中恒星产生的微透镜放大率的波长依赖性（色度），导出了透镜类星体SBS 0909+532吸积盘的尺寸和温度分布。在使用14条发射线的通量比校正消光后，我们观察到B-A通量比随波长发生显着变化，从（静止坐标系）1460 Å处的-0.67 ± 0.05 mag变化到6560 Å处的-0.24 ± 0.07 mag。对于λ = 7000 nm，消光和微透镜效应看起来都很小。模拟表明，图像B而不是A是强微透镜。如果我们使用高斯源模拟磁盘大小从1460 nm到6560 nm的变化，（I exp（−R2/2 r2 s）），当圆盘大小与波长成比例时，我们发现在1460 nm处rs = 7+5−3光日，对于rs和p的均匀先验，p = 0.9+0.6−0.3，rs = 4+3−3光日，p = 1.0+0.6−0.4。考虑到不确定性，圆盘温度分布T <$R−1/p与薄圆盘理论（T <$R−3/4）一致。rs的估计也与薄盘理论使用估计的黑洞质量（MBH = 2 × 109 M）推断的尺寸一致，但与薄盘理论和光通量估计的较小尺寸不一致。我们还利用非微透镜发射线的通量比来确定透镜星系中尘埃的消光曲线，发现它与LMC 2超壳层的消光曲线相似。
We derive the size and temperature profile of the accretion disk of the lensed quasar SBS 0909+532 by measuring the wavelength dependence (chromaticity) of the microlensing magnification produced by the stars in the lens galaxy. After correcting for extinction using the flux ratios of 14 emission lines, we observe a marked change in the B–A flux ratio with wavelength, varying from −0.67 ± 0.05 mag at (rest frame) ∼1460 Å to −0.24 ± 0.07 mag at ∼6560 Å. For λ ≳ 7000 Å both effects, extinction and microlensing, look minimal. Simulations indicate that image B rather than A is strongly microlensed. If we model the change in disk size from 1460 Å to 6560 Å using a Gaussian source (I ∝ exp(−R2/2r2s)) with a disk size scaling with wavelength as rs ∝ λp, we find rs = 7+5−3 light-days at 1460 Å and p = 0.9+0.6−0.3 for uniform priors on rs and p, and rs = 4+3−3 light-days and p = 1.0+0.6−0.4 for a logarithmic prior on rs. The disk temperature profile T ∝ R−1/p is consistent with thin disk theory (T ∝ R−3/4), given the uncertainties. The estimates of rs are also in agreement with the size inferred from thin disk theory using the estimated black hole mass (MBH ≃ 2 × 109 M☉) but not with the smaller size estimated from thin disk theory and the optical flux. We also use the flux ratios of the unmicrolensed emission lines to determine the extinction curve of the dust in the lens galaxy, finding that it is similar to that of the LMC2 Supershell.