Space Pnysics Developed by High-Precise Astrometry

高精度天体测量学开发的空间物理学

• 批准号: 12640242
• 负责人: TSUJIMOTO Takuji
• 金额: $ 0.83万
• 依托单位: National Astronomical Observatory
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640242/
• 关键词: Astrometry; Hipparcos; DIVA; FAME; 高精度位置天文観測

The Hipparcos satellite have brought us a new era for the distance determination using the trigonometric parallaxes π of stars. Before Hipparcos, the ground-based observations offered π only for stars within a few tens pc, - and we are already at the stage to obtain π for stars with their distances extending to -1-2 kpc. As a result, the Hipparcos catalog invloves many valuable stars, of which Cepheid variables and RR Lyrae stars which serve as primary distance indicators are included. It is well-known that Cepheids obey the period-luminosity (PL) relation. The zero-point for PL gives a distance modulus MLMC to the Large Magellanic Cloud (LMC), which is no doubt an important step for determining the distances to distant galaxies and thus for the Bubble constant (H0). In the same manner, the RR ALyraes which obey the metallicty-luminosity (ML) relation also provide ^LMC- In addition, they are indeed used to determine the distances to the Galactic globular clusters and hence their ages. … More Instead of the indirect calibrations of these zero-points so far, Hipparcos has enabled us to derive them directly from π of Galactic Cepheids and RR Lyraes for the first time. However, in fact, direct calibrations have confronted a serious problem which comes from the fact that almost all of π for these variables are measured with very large error including negative parallaxes. In such a case, the distance d for each variable cannot be calculated from d(pc) = I/π. We therefore need do deduce the physical quantities statistically from the ensemble of Hipparcos parallaxes. In this research, we investigate how rigorous two statistical methods are to calibrate Hipparcos parallaxes. All discussions will end in the settlement of JILMC given by Hipparcos variables. The precise determination of biases and variances involved in the final results by the statistical calibrations is certainly required for not only the further study using Hipparcos data but also the future work using the highly-precise astrometric data brought by the ongoing space satellite projects such as DIVA and FAME. Less

依巴谷卫星的出现为利用恒星的三角视差π进行距离测量开创了新的纪元。在依巴谷之前，地面观测只提供了几十秒差距以内的恒星的π，而我们已经处于获得距离延伸到-1-2千秒差距的恒星的π的阶段。依巴谷星表包含了许多有价值的恒星，其中造父变星和天琴座RR型星是主要的距离指示星。造父变星服从周期-光度（PL）关系。PL的零点给出了MLMC到大麦哲伦云（LMC）的距离模，这无疑是确定到遥远星系的距离以及气泡常数（H 0）的重要步骤。同样地，服从金属量-光度（ML）关系的RR ALyraes也提供^LMC。此外，它们确实被用来确定到银河系球状星团的距离，从而确定它们的年龄。 ...更多信息 到目前为止，依巴谷没有间接校准这些零点，而是首次使我们能够直接从银河系造父变星和天琴座RR的π中导出它们。然而，实际上，直接校准面临着一个严重的问题，这是因为这些变量的几乎所有π都是以非常大的误差测量的，包括负松弛。在这种情况下，每个变量的距离d不能由d（pc）= I/π计算。因此，我们需要从依巴谷星系系综中统计地推导出物理量。在这项研究中，我们调查如何严格的两种统计方法是校准依巴谷松。所有的讨论都将以依巴谷变量给出的JILMC的解决为结束。精确确定统计校准最终结果中涉及的偏差和方差，不仅是利用依巴谷数据进行进一步研究的必要条件，而且也是利用正在进行的空间卫星项目（如DIVA和FAME）带来的高精度天体测量数据进行未来工作的必要条件。少

项目成果

Tsujimoto, T, Shigeyama, T.: "SN1987A revisited as a major production site for r-process elements"The Astrophysical Journal. 561. L97-L100 (2001)

Tsujimoto, T, Shigeyama, T.：“SN1987A 重新成为 r 过程元素的主要生产基地”《天体物理学杂志》。

Tsujimoto, T. et al.: "Chemical Evolution of odd elements in an inhomogeneous early galaxy"The Astrophysical Journal. 565. 1011-1016 (2002)

Tsujimoto, T. 等人：“不均匀早期星系中奇数元素的化学演化”《天体物理学杂志》。

Kobayashi, C., Tsujimoto, T., Nomoto, K.: "The history of the Cosmic Supernoua rate derived from the ebolution of the host galaxies"The Astrophysical Journal. 539. 26-38 (2000)

Kobayashi, C.、Tsujimoto, T.、Nomoto, K.：“源自宿主星系演化的宇宙 Supernoua 速率的历史”《天体物理学杂志》。

Tsujimoto, T., Shigeyama, T.: "SN1987A revisited as a major production site for r-process elements"The Astrophysical Journal. 561. 97-100 (2001)

Tsujimoto, T.、Shigeyama, T.：“SN1987A 重新成为 r 过程元素的主要生产基地”《天体物理学杂志》。

Tsujimoto,T.,Shigeyama,T.,Yoshii,Y.: "Probing the site for r-process Nucleosynthesis with abundances of barium and magnesium in extremely metal-poor stars"The Astrophysical Journal Letters. 531. 33-36 (2000)

Tsujimoto,T.、Shigeyama,T.、Yoshii,Y.：“探索在极度贫金属恒星中富含钡和镁的 r 过程核合成场所”《天体物理学杂志快报》。