Table · dataset · 2024
Galactic globular clusters shapes
Listed in IVOA Registry (Virtual Observatory)
We homogeneously measured the elliptical shapes of 163 Globular Clusters (GCs) using the on-sky distribution of their cluster members and the third data release of the ESA mission Gaia (DR3).
Description
The astrometry enables the differentiation of stars within clusters from those in the field. This feature is particularly valuable for clusters located in densely populated areas of the sky, where the conventional methods for measuring the geometry of the GCs are not applicable.
The median axial ratio of our full sample is <b/a>=0.935^+0.033^_-0.090_, and 0.986^+0.009^_-0.004_ for the subset of 11 GCs previously studied based on HST imaging. We investigated whether the minor axis of the ellipses can be interpreted as a pseudo-rotation axis by comparing it to measurements of cluster rotation. Using the radial velocities from Gaia, we detected rotation for three clusters, NGC 5139, NGC 104, and NGC 6341, and observed alignment between the pseudo-rotation axis and the 2D projection of the real rotation axis.
Read the rest (2 more)
To expand the set of clusters for which rotation has been detected, we analyzed multiple literature references. Depending on the reference used for comparison, we observed alignment in between 76% to 100% of the clusters. The lack of alignment observed in some clusters may be linked to the fact that some studies analyze different scales, since multiple studies have demonstrated that the orientation of rotation varies with the distance from the center.
We estimate that the next Gaia release will increase the number of stars with radial velocities in GCs from ~10000 in Gaia DR3 to ~55000 in Gaia DR4. This will enable the measurement of rotation and ellipticities at identical angular scales for additional clusters, which will help to clarify whether the previously mentioned alignment occurs across all clusters.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/689/A232 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2024A&A...689A.232C ui.adsabs.harvard.edu/abs/2024A%26A...689A.232C ↗
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/a%2Ba/689/a232 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Optical
- From keywords
- Astronomy & Astrophysics
- Inferred from text
- Astronomical sciences 73% · Imaging 75%
Provenance · 1 source records, 10 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/a+a/689/a232 | 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 (73%) |
| 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 | |
| concepts[modality].local:modality:imaging | enrichment · IVOA Registry | keyword-concept-rules@1.0.0 | title+description (75%) |
| 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 |