The photometric structure of the inner Galaxy
The photometric structure of the inner Galaxy
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DOI：
10.1093/mnras/288.2.365
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发表时间：
1996-09
影响因子：
4.8
通讯作者：
J. Binney;O. Gerhard;David Spergel Dpt.Theoret.Phys.;Oxford;UK.;Astron.Inst.;Univ.Basel;Ch;P. Obs.;Usa
中科院分区：
文献类型：
--
作者：
J. Binney;O. Gerhard;David Spergel Dpt.Theoret.Phys.;Oxford;UK.;Astron.Inst.;Univ.Basel;Ch;P. Obs.;Usa
银河系内部几千秒差距的光分布是从经过尘埃校正的银河系内部近红外 COBEIDIRBE 表面亮度图以非参数方式恢复的。当假设太阳位于平面上方 -14 ± 4 pc 时，可以获得最适合光度测量的结果。恢复的密度分布清楚地显示了高度非轴对称圆盘中的细长三维凸起。在受欢迎的模型中，凸出部的轴比为 1:0.6:0.4，半长轴长度为 -2 kpc。它的较近的长轴位于第一象限。凸起被椭圆盘包围，椭圆盘在短轴上延伸至-2 kpc，在长轴上延伸至-3.Skpc。在所有模型中，沿短轴的局部密度最小值为 -2.2kpc。随后沿着短轴的最大值-3kpc（对应于I=-22°和I=17°）可以与拉格朗日点L4相关联。根据该识别和凸出条的长度，我们推断出条的模式速度 Db = 60-70 km s -1 kpc -1 。在假设银河系八重或四重对称的情况下对从螺旋结构模型得出的伪数据进行反投影的实验表明，从 COBE 数据恢复的高度非轴对称圆盘可以反映银河系内的螺旋结构，如果该结构在近红外波长处涉及大于约 3 的密度对比度。这些实验表明，太阳中心线与凸起主轴线之间的角度 CPo 接近 20°。
The light distribution in the inner few kiloparsecs of the Milky Way is recovered non parametrically from a dust-corrected near-infrared COBEIDIRBE surface brightness map of the inner Galaxy. The best fits to the photometry are obtained when the Sun is assumed to lie -14 ± 4 pc above the plane. The recovered density distributions clearly show an elongated three-dimensional bulge set in a highly non-axisymmetric disc. In the favoured models, the bulge has axis ratios 1 : 0.6: 0.4 and semi-major axis length -2 kpc. Its nearer long axis lies in the first quadrant. The bulge is surrounded by an elliptical disc that extends to -2 kpc on the minor axis and -3.Skpc on the major axis. In all models there is a local density minimum -2.2kpc down the minor axis. The subsequent maximum - 3 kpc down the minor axis (corresponding to I = -22° and I = 17°) may be associated with the Lagrange point L4 . From this identification and the length of the bulge-bar, we infer a pattern speed Db = 60-70 km s -1 kpc -1 for the bar. Experiments in which pseudo-data derived from models with spiral structure were deprojected under the assumption that the Galaxy is either eight-fold or four-fold symmetric indicate that the highly non-axisymmetric discs recovered from the COBE data could reflect spiral structure within the Milky Way if that structure involves density contrasts greater than ~3 at near-infrared wavelengths. These experiments indicate that the angle CPo between the Sun-centre line and a major axis of the bulge lies near 20°.