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Photometric and kinematic studies of extragalactic globular cluster systems.

机译:河外球状星团系统的光度学和运动学研究。

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摘要

Globular clusters (GCs) are old, luminous, compact collections of stars found in galaxy halos that formed during the early stages of galaxy formation. Because of this, GCs serve as excellent tracers of the formation, structure, and merger history of their host galaxies. My dissertation will examine both the photometric and kinematic properties of GC systems and their relationship to their host galaxies.;In the first section, I will present the analysis of the GC systems of two spiral galaxies, NGC 891 and NGC 1055. I will discuss the photometric methods used to detect GCs using wide-field BVR imaging and to quantify the global properties of the system such as the total number of GCs and their radial distribution. My results for these two GC systems were compared to those of other galaxies.;I will also present the results of spectroscopic follow-up for two giant galaxies: the S0 galaxy NGC 4594 (M104), and the elliptical galaxy NGC 3379 (M105). I measured the radial velocities of GCs in these two galaxies, and combined them with published results to determine the mass distribution and mass-to-light (M/L) ratio profile for each galaxy out to large effective radius (7-9 Re). For both galaxies, I found that the M/L profiles increase with radius and do not flatten, which suggests that the dark matter halos in these galaxies extend to the edge of my data. I also looked for evidence of rotation in the GC systems, and found that neither system exhibits significant rotation around the host galaxy. I examined the velocity dispersion profile of each GC system and found kinematic differences between the red and blue GC subpopulations. Finally, I compared my results to mass estimates for these galaxies from other kinematic tracers and considered them in the context of galaxy formation models.
机译:球状星团(GCs)是星系形成初期形成的星系光晕中发现的古老,发光,紧凑的恒星集合。因此,GC可以很好地追踪其宿主星系的形成,结构和合并历史。我的论文将研究GC系统的光度学和运动学特性,以及它们与宿主星系的关系。在第一部分中,我将对两个螺旋星系NGC 891和NGC 1055的GC系统进行分析。使用广域BVR成像检测GC的光度法,并量化系统的整体属性,例如GC的总数及其径向分布。我将这两个GC系统的结果与其他星系的结果进行了比较。;我还将介绍两个巨型星系的光谱学跟踪结果:S0星系NGC 4594(M104)和椭圆星系NGC 3379(M105) 。我测量了这两个星系中GC的径向速度,并将它们与已发表的结果结合起来,确定了在较大有效半径(7-9 Re)范围内每个星系的质量分布和质/光(M / L)比分布。对于这两个星系,我发现M / L轮廓随半径增加而不会变平,这表明这些星系中的暗物质光晕扩展到了我数据的边缘。我还寻找了GC系统中旋转的证据,发现这两个系统均未显示出围绕宿主星系的明显旋转。我检查了每个GC系统的速度色散曲线,发现红色和蓝色GC子群之间的运动学差异。最后,我将我的结果与其他运动学示踪剂对这些星系的质量估计进行了比较,并在星系形成模型的背景下考虑了它们。

著录项

  • 作者

    Dowell, Jessica.;

  • 作者单位

    Indiana University.;

  • 授予单位 Indiana University.;
  • 学科 Physics Astronomy and Astrophysics.
  • 学位 Ph.D.
  • 年度 2015
  • 页码 219 p.
  • 总页数 219
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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