Search and characterization of satellite galaxies and stellar streams
Narrow-band photometry applications for galactic archaeology
The modeling of stellar populations and detailed abundance patterns
| Full text | |
| Author(s): Show less - |
Limberg, Guilherme
;
Ji, Alexander P.
;
Naidu, Rohan P.
;
Chiti, Anirudh
;
Rossi, Silvia
;
Usman, Sam A.
;
Ting, Yuan-Sen
;
Zaritsky, Dennis
;
Bonaca, Ana
;
Borbolato, Lais
;
Speagler, Joshua S.
;
Chandra, Vedant
;
Conroy, Charlie
Total Authors: 13
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 530, n. 3, p. 14-pg., 2024-04-25. |
| Abstract | |
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. (AU) | |
| FAPESP's process: | 22/07301-5 - Chemical-abundance patterns of disrupted dwarf galaxies |
| Grantee: | Guilherme Limberg |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate (Direct) |
| FAPESP's process: | 21/10429-0 - The chemodynamical structure of the ancient galactic halo |
| Grantee: | Guilherme Limberg |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |
| FAPESP's process: | 15/50374-0 - Mosaic: the multi-object spectrograph for the ESO Extremely Large Telescope |
| Grantee: | Silvia Cristina Fernandes Rossi |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 20/15245-2 - The multi-object spectrograph (MOSAIC) for the extremely large telescope: spectroscopy of stellar populations in the milky way and external galaxies |
| Grantee: | Beatriz Leonor Silveira Barbuy |
| Support Opportunities: | Special Projects |