Table · dataset · 2023
Chemical abundances for 5 stars in Tucana II
Listed in IVOA Registry (Virtual Observatory)
We present chemical abundances and velocities of five stars between 0.3 and 1.1kpc from the center of the TucanaII ultrafaint dwarf galaxy (UFD) from high-resolution Magellan/MIKE spectroscopy.
Description
We find that every star is deficient in metals (-3.6<[Fe/H]<-1.9) and in neutron-capture elements as is characteristic of UFD stars, unambiguously confirming their association with TucanaII. Other chemical abundances (e.g., C, iron peak) largely follow UFD trends and suggest that faint core-collapse supernovae (SNe) dominated the early evolution of TucanaII.
We see a downturn in [{alpha}/Fe] at [Fe/H]~-2.8, indicating the onset of Type Ia SN enrichment and somewhat extended chemical evolution. The most metal-rich star has strikingly low [Sc/Fe]=-1.29{+/-}0.48 and [Mn/Fe]=-1.33{+/-}0.33, implying significant enrichment by a sub-Chandrasekhar mass Type Ia SN. We do not detect a radial velocity gradient in TucanaII (dv_helio_/d{theta}_1_=-2.6_-2.9_^+3.0^km/s/kpc), reflecting a lack of evidence for tidal disruption, and derive a dynamical mass of M_1/2_(r_h_)=1.6_-0.7_^+1.1^x10^6^M{sun}.
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We revisit formation scenarios of the extended component of TucanaII in light of its stellar chemical abundances. We find no evidence that TucanaII had abnormally energetic SNe, suggesting that if SNe drove in situ stellar halo formation, then other UFDs should show similar such features. Although not a unique explanation, the decline in [{alpha}/Fe] is consistent with an early galactic merger triggering later star formation.
Future observations may disentangle such formation channels of UFD outskirts.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/165/55 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2023AJ....165...55C ui.adsabs.harvard.edu/abs/2023AJ....165...55C ↗
publication · from IVOA Registry
Catalogue records · 2
- VOResource record dc.g-vo.org/oai.xml?verb=GetRecord&metadataPrefix=ivo_vor&identifier=ivo%3… ↗
metadata API · from IVOA Registry
- Registry record (GAVO) dc.g-vo.org/I/cds.vizier/j/aj/165/55 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Optical
- From keywords
- Astronomy & Astrophysics
- Inferred from text
- Astronomical sciences 71%
Provenance · 1 source records, 9 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/aj/165/55 | 13 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[field].anzsrc:group:5101 | enrichment · IVOA Registry | taxonomy-embedding@1.1.0 | title+keywords+description (71%) |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:optical | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| description | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_description |
| license_text | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| publication_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| title | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_title |
| updated_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 |