距离大麦哲伦云的精确度为百分之一
G Pietrzyński1,2, D Graczyk3,4,5, A Gallenne6,7
1Nicolaus Copernicus Astronomical Centre, Warsaw, Poland. pietrzyn@camk.edu.pl.
Nature
|March 15, 2019
概括
天文学家准确地测量了大麦哲伦星云的距离, 这种改进的校准改进了宇宙距离尺度,并有助于确定哈勃常数.
科学领域:
- 宇宙学
- 天体物理学
- 恒星天文学
背景情况:
- 确定哈勃常数需要精确的经验测量.
- 对于宇宙距离尺度的校准而言,Cepheid周期-亮度关系至关重要.
- 大麦哲伦云是这个校准的关键,传统上是使用Cepheid变量进行研究的.
研究的目的:
- 提高表面亮度与颜色关系校准的精度.
- 为了更准确地确定大麦哲伦云的几何距离.
- 为了减少宇宙距离尺度和哈勃恒定测量的不确定性.
主要方法:
- 使用了20个日食双星系统,由晚期的恒星组成.
- 用0.8%的精度校准了表面亮度与颜色的关系.
- 应用这个校准来推导到大马格伦云的精确距离.
主要成果:
- 在表面亮度与颜色关系校准中达到0.8%的精度.
- 用1%的精度确定了大马格伦云的几何距离.
- 最终距离为49.59±0.09 (统计) ±0.54 (系统) 公分.
结论:
- 新的校准显著提高了大麦哲伦云距离测量的准确性.
- 这种进步为宇宙距离阶梯提供了更精确的.
- 在精确宇宙学时代,为哈勃常数的更准确的确定做出了贡献.
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