Extending the chemical reach of the H3 survey: detailed abundances of the dwarf-galaxy stellar stream Wukong/LMS-1

被引：6

作者：

Limberg, Guilherme ^{[1
,2
,3
]}

Ji, Alexander P. ^{[2
,3
]}

Naidu, Rohan P. ^{[4
,5
]}

Chiti, Anirudh ^{[2
,3
]}

Rossi, Silvia ^{[1
]}

Usman, Sam A. ^{[2
,3
]}

Ting, Yuan-Sen ^{[6
,7
,8
]}

Zaritsky, Dennis ^{[9
]}

Bonaca, Ana ^{[10
]}

Borbolato, Lais ^{[1
]}

Speagler, Joshua S. ^{[11
,12
,13
,14
]}

Chandra, Vedant ^{[15
]}

Conroy, Charlie ^{[15
]}

机构：

[1] Univ Sao Paulo, Dept Astron, IAG, BR-05508090 Sao Paulo, SP, Brazil

[2] Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA

[3] Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA

[4] MIT, Dept Phys, Cambridge, MA 02139 USA

[5] MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA

[6] Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia

[7] Australian Natl Univ, Sch Comp, Acton, ACT 2601, Australia

[8] Ohio State Univ, Dept Astron, 140 West 18th Ave, Columbus, OH 43210 USA

[9] Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA

[10] Observ Carnegie Inst Sci, 813 Santa Barbara St, Pasadena, CA 91101 USA

[11] Univ Toronto, Dept Stat Sci, Toronto, ON M5G 1Z5, Canada

[12] Univ Toronto, David A Dunlap Dept Astron & Astrophys, Toronto, ON M5S 3H4, Canada

[13] Univ Toronto, Dunlap Inst Astron & Astrophys, Toronto, ON M5S 3H4, Canada

[14] Univ Toronto, Dept Stat Sci, Toronto, ON M5G 1Z5, Canada

[15] Harvard & Smithsonian, Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 2024年 / 530卷 / 03期

基金：

巴西圣保罗研究基金会; 美国国家科学基金会; 澳大利亚研究理事会;

关键词：

stars: abundances; Galaxy: halo; Galaxy: kinematics and dynamics; galaxies: dwarf; Local Group; METAL-POOR STARS; DISTINCT HALO POPULATIONS; NEUTRON-CAPTURE ELEMENTS; R-PROCESS ENRICHMENT; UV LEGACY SURVEY; MILKY-WAY; GLOBULAR-CLUSTER; SAGITTARIUS STREAM; SOLAR NEIGHBORHOOD; GALACTIC ARCHAEOLOGY;

D O I：

10.1093/mnras/stae969

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present the first detailed chemical-abundance analysis of stars from the dwarf-galaxy stellar stream Wukong/LMS-1 covering a wide metallicity range (-3.5 < [Fe/H] less than or similar to -1.3). We find abundance patterns that are effectively indistinguishable from the bulk of Indus and Jhelum, a pair of smaller stellar streams proposed to be dynamically associated with Wukong/LMS-1. We confirmed a carbon-enhanced metal-poor star ([C/Fe] > +0.7 and [Fe/H] similar to -2.9) in Wukong/LMS-1 with strong enhancements in Sr, Y, and Zr, which is peculiar given its solar-level [Ba/Fe]. Wukong/LMS-1 stars have high abundances of alpha elements up to [Fe/H] greater than or similar to -2$, which is expected for relatively massive dwarfs. Towards the high-metallicity end, Wukong/LMS-1 becomes alpha-poor, revealing that it probably experienced fairly standard chemical evolution. We identified a pair of N- and Na-rich stars in Wukong/LMS-1, reminiscent of multiple stellar populations in globular clusters. This indicates that this dwarf galaxy contained at least one globular cluster that was completely disrupted in addition to two intact ones previously known to be associated with Wukong/LMS-1, which is possibly connected to similar evidence found in Indus. From these >= 3 globular clusters, we estimate the total mass of Wukong/LMS-1 to be approximate to 10(10)M(circle dot), representing similar to 1 per cent of the present-day Milky Way. Finally, the [Eu/Mg] ratio in Wukong/LMS-1 continuously increases with metallicity, making this the first example of a dwarf galaxy where the production of r-process elements is clearly dominated by delayed sources, presumably neutron-star mergers.

引用

页码：2512 / 2525

页数：14