Edinburgh Research Explorer

Siriusly, a newly identified intermediate-age Milky Way stellar cluster: a spectroscopic study of Gaia 1

Research output: Contribution to journalArticle

Related Edinburgh Organisations

Open Access permissions

Open

Documents

http://adsabs.harvard.edu/abs/2017MNRAS.471.4087S
Original languageEnglish
Pages (from-to)4087-4098
JournalMonthly Notices of the Royal Astronomical Society
Volume471
Issue number4
DOIs
Publication statusPublished - 26 Jul 2017

Abstract

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}× 10^3 M_{⊙}. 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: z_{max}=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.

    Research areas

  • catalogues, Galaxy: general, Galaxy: structure

Download statistics

No data available

ID: 43238688