首页    期刊浏览 2025年02月23日 星期日
登录注册

文章基本信息

  • 标题:Multiple Populations in NGC 1851: Abundance Variations and UV Photometric Synthesis in the Washington and HST/WFC3 Systems
  • 本地全文:下载
  • 作者:Jeffrey D. Cummings ; D. Geisler ; S. Villanova
  • 期刊名称:The Astronomical journal
  • 印刷版ISSN:0004-6256
  • 电子版ISSN:1538-3881
  • 出版年度:2017
  • 卷号:153
  • 期号:4
  • DOI:10.3847/1538-3881/aa63e5
  • 语种:English
  • 出版社:American Institute of Physics
  • 摘要:The analysis of multiple populations (MPs) in globular clusters (GCs), both spectroscopically and photometrically, is key in understanding their formation and evolution. The relatively narrow Johnson U, F336W, and Stromgren and Sloan u filters have been crucial in exhibiting these MPs photometrically, but in Paper I we showed that the broader Washington C filter can more efficiently detect MPs in the test case GC NGC 1851. Additionally, In Paper I we detected a double main sequence (MS) that has not been detected in previous observations of NGC 1851. We now match this photometry to NGC 1851's published RGB abundances and find that the two RGB branches observed in C generally exhibit different abundance characteristics in a variety of elements (e.g., Ba, Na, and O) and in CN band strengths, but no single element can define the two RGB branches. However, simultaneously considering [Ba/Fe] or CN strength with either [Na/Fe], [O/Fe], or CN strength can separate the two photometric RGB branches into two distinct abundance groups. Matches of NGC 1851's published SGB and HB abundances to the Washington photometry shows consistent characterizations of the MPs, which can be defined as an O-rich/N-normal population and an O-poor/N-rich population. Photometric synthesis for both the Washington C filter and the F336W filter finds that these abundance characteristics, with appropriate variations in He, can reproduce for both filters the photometric observations in both the RGB and the MS. This photometric synthesis also confirms the throughput advantages that the C filter has in detecting MPs.
  • 关键词:globular clusters: general;globular clusters: individual (NGC 1851);techniques: photometric
国家哲学社会科学文献中心版权所有