The Time Delays of Gravitational Lens HE 0435–1223: An Early-Type Galaxy with a Rising Rotation Curve
The Time Delays of Gravitational Lens HE 0435–1223: An Early-Type Galaxy with a Rising Rotation Curve
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DOI：
10.1086/499766
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发表时间：
2005-08
期刊：
影响因子：
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通讯作者：
C. Kochanek;N. Morgan;E. Falco;B. McLeod;J. Winn;J. Dembicky;B. G. D. O. Astronomy;T. U. O. S. D. A. Observatory
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文献类型：
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作者：
C. Kochanek;N. Morgan;E. Falco;B. McLeod;J. Winn;J. Dembicky;B. G. D. O. Astronomy;T. U. O. S. D. A. Observatory
我们给出了哈勃太空望远镜的图像和两年来对四类星体HE0435-1223的光学测光。类星体内部变化之间的时间延迟分别为ΔTAD=-14.37天，ΔTAB=-8.00天，ΔTAC=-2.10天。我们还观察到了~0.1mag/yr~(-1)的非内禀变化，我们将其归因于微透镜效应。我们假定透镜星系的自转曲线，然后推导出哈勃常数(H0)，而不是假设H0=(72±7)km S-1 Mpc-1，并推导出对自转曲线的约束。在透镜图像出现的尺度上(1.“2=5h-1kpc≃1.5Re)，透镜星系必须有一个上升的自转曲线，它不能有恒定的质光比。这些结果进一步证明了早期类型星系的结构是不均匀的。
We present Hubble Space Telescope images and 2 years of optical photometry of the quadruple quasar HE 0435-1223. The time delays between the intrinsic quasar variations are ΔtAD = -14.37, ΔtAB = -8.00, and ΔtAC = -2.10 days. We also observed nonintrinsic variations of ~0.1 mag yr-1 that we attribute to microlensing. Instead of the traditional approach of assuming a rotation curve for the lens galaxy and then deriving the Hubble constant (H0), we assume H0 = (72 ± 7) km s-1 Mpc-1 and derive constraints on the rotation curve. On the scale over which the lensed images occur (1.″2 = 5 h-1 kpc ≃ 1.5Re), the lens galaxy must have a rising rotation curve, and it cannot have a constant mass-to-light ratio. These results add to the evidence that the structures of early-type galaxies are heterogeneous.