| Title: |
Siriusly, a newly identified intermediate-age Milky Way stellar cluster: a spectroscopic study of Gaia |
| Authors: |
Simpson, JD; Silva, GMD; Martell, SL; Zucker, DB; Ferguson, AMN; Bernard, EJ; Irwin, M; Penarrubia, J; Tolstoy, E |
| Source: |
urn:ISSN:0035-8711 ; urn:ISSN:1365-2966 ; Monthly Notices of the Royal Astronomical Society, 471, 4, 4087-4098 |
| Publisher Information: |
Oxford University Press |
| Publication Year: |
2017 |
| Collection: |
UNSW Sydney (The University of New South Wales): UNSWorks |
| Subject Terms: |
5109 Space Sciences; 51 Physical Sciences; anzsrc-for: 5109 Space Sciences; anzsrc-for: 51 Physical Sciences; anzsrc-for: 0201 Astronomical and Space Sciences; anzsrc-for: 5101 Astronomical sciences; anzsrc-for: 5107 Particle and high energy physics |
| Description: |
We confirm the reality of the recently discovered Milky Way stellar cluster Gaia 1 using spectra acquired with the HERMES and AAOmega spectrographs of the Anglo-Australian Telescope. This cluster had been previously undiscovered due to its close angular proximity to Sirius, the brightest star in the sky at visual wavelengths. Our observations identified 41 cluster members, and yielded an overall metallicity of [Fe/H]=−0.13±0.13 and barycentric radial velocity of vr = 58.30 ± 0.22 km s−1. These kinematics provide a dynamical mass estimate of 12.9+4.6−3.9×103M⊙. Isochrone fits to Gaia, 2MASS, and Pan-STARRS1 photometry indicate that Gaia 1 is an intermediate age (∼3 Gyr) stellar cluster. Combining the spatial and kinematic data we calculate Gaia 1 has a circular orbit with a radius of about 12 kpc, but with a large out of plane motion: zmax=1.1+0.4−0.3 kpc. Clusters with such orbits are unlikely to survive long due to the number of plane passages they would experience. |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
unknown |
| Relation: |
https://hdl.handle.net/1959.4/unsworks_63130; https://doi.org/10.1093/mnras/stx1892 |
| DOI: |
10.1093/mnras/stx1892 |
| Availability: |
https://hdl.handle.net/1959.4/unsworks_63130; https://unsworks.unsw.edu.au/bitstreams/8d7d65a9-d203-42da-b307-adfac4c774b2/download; https://doi.org/10.1093/mnras/stx1892 |
| Rights: |
open access ; https://purl.org/coar/access_right/c_abf2 ; CC-BY-NC-ND ; https://creativecommons.org/licenses/by-nc-nd/4.0/ ; free_to_read ; This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. https://doi.org/10.1093/mnras/stx1892 |
| Accession Number: |
edsbas.71920CA6 |
| Database: |
BASE |