Keck/KCWI Spectroscopy of Globular Clusters in Local Volume Dwarf Galaxies

IF 4.5 3区物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS

Publications of the Astronomical Society of Australia Pub Date : 2024-05-20 DOI:10.1017/pasa.2024.41

D. Forbes, Daniel Lyon, J. Gannon, A. Romanowsky, J. Brodie

引用次数: 0

Abstract

A number of nearby dwarf galaxies have globular cluster (GC) candidates that require spectroscopic confirmation. Here we present Keck telescope spectra for 15 known GCs and GC candidates that may be associated with a host dwarf galaxy, and an additional 3 GCs in the halo of M31 that are candidates for accretion from a now disrupted dwarf galaxy. We confirm 6 star clusters (of intermediate-to-old age) to be associated with NGC 247. The vast bulk of its GC system remains to be studied spectroscopically. We also confirm the GC candidates in F8D1 and DDO190, finding both to be young star clusters. The 3 M31 halo GCs all have radial velocities consistent with M31, are old and very metal-poor. Their ages and metallicities are consistent with accretion from a low mass satellite galaxy. Finally, three objects are found to be background galaxies – two are projected near NGC 247 and one (candidate GCC7) is near the IKN dwarf. The IKN dwarf thus has only 5 confirmed GCs but still a remarkable specific frequency of 124.

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Keck/KCWI 对本地体积矮星系球状星团的光谱分析

许多附近的矮星系都有球状星团（GC）候选体，需要通过光谱来确认。在这里，我们展示了 15 个已知球状星团和可能与主矮星系有关的候选球状星团的凯克望远镜光谱，以及另外 3 个位于 M31 光环中的候选球状星团的光谱，这些候选球状星团可能是由一个现已解体的矮星系吸积而来的。我们确认了与NGC 247相关的6个星团（年龄介于中老年之间）。它的大部分星团系统还有待光谱学研究。我们还确认了 F8D1 和 DDO190 中的候选 GC，发现它们都是年轻的星团。3 个 M31 光环 GC 的径向速度都与 M31 一致，都很老，而且金属含量很低。它们的年龄和金属性都与低质量卫星星系的吸积相一致。最后，有三个天体被发现是背景星系--两个投影在NGC 247附近，一个（候选GCC7）在IKN矮星系附近。因此，IKN矮星系只有5个被证实的GC，但其特定频率仍然高达124。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Publications of the Astronomical Society of Australia 地学天文-天文与天体物理

CiteScore

5.90

自引率

9.50%

发文量

审稿时长

>12 weeks

期刊介绍： Publications of the Astronomical Society of Australia (PASA) publishes new and significant research in astronomy and astrophysics. PASA covers a wide range of topics within astronomy, including multi-wavelength observations, theoretical modelling, computational astronomy and visualisation. PASA also maintains its heritage of publishing results on southern hemisphere astronomy and on astronomy with Australian facilities. PASA publishes research papers, review papers and special series on topical issues, making use of expert international reviewers and an experienced Editorial Board. As an electronic-only journal, PASA publishes paper by paper, ensuring a rapid publication rate. There are no page charges. PASA''s Editorial Board approve a certain number of papers per year to be published Open Access without a publication fee.