Chemodynamic evolution of Sun-like stars in nearby moving groups

Abstract

Sun-like stars are well represented in the solar neighbourhood but are currently under-utilised, with many studies of chemical and kinematic evolution focusing on red giants (which can be observed further away) or turn-off stars (which have well measured ages). Recent surveys (e.g. GALAH) provide spectra for large numbers of nearby Sun-like stars, which provides an opportunity to apply our newly developed method for measuring metallicities, temperatures, and surface gravities - the EPIC algorithm - which yields improved ages via isochrone fitting. We test this on moving groups, by applying it to the large GALAH DR3 sample. This defines a sample of 72,288 solar analogue targets for which the stellar parameter measurements are most precise and reliable. These stars are used to estimate, and test the accuracy and precision of, age measurements derived with the SAMD isochrone fitting algorithm. Using these ages, we recover the age-metallicity relationships for nearby (<= 1 kpc) moving groups, traced by solar analogues, and analyse them with respect to the stellar kinematics. In particular, we found that the age-metallicity relationships of all moving groups follows a particular trend of young (age < 6 Gyr) stars having constant metallicity and older (age >= 6 Gyr) stars decreasing in metallicity with increasing age. The Hercules stream carries the highest fraction of metal-rich young stars (~ 0.1 dex) in our sample, which is consistent with a migrating population of stars from the inner Galaxy, and we discuss the possible causes of this migration in the context of our results.

13 pages, 10 figures, accepted to MNRAS

References in corpus (21)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• galpy: A Python Library for Galactic Dynamics
• The mass distribution and gravitational potential of the Milky Way
• Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole
• Riding the Spiral Waves: Implications of Stellar Migration for the Properties of Galactic Disks
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs
• CMasher: Scientific colormaps for making accessible, informative and 'cmashing' plots
• The age-metallicity structure of the Milky Way disk
• The Galactic radial abundance gradients of C, N, O, Ne, S, Cl and Ar from deep spectra of H II regions
• The Rich Are Different: Evidence from the RAVE Survey for Stellar Radial Migration
• Early turbulent mixing as the origin of chemical homogeneity in open star clusters
• Quantifying stellar radial migration in an N-body simulation: blurring, churning, and the outer regions of galaxy discs
• Why the Milky Way's bulge is not only a bar formed from a cold thin disk
• Chemical abundances in the nucleus of the Sagittarius dwarf spheroidal galaxy
• The Open Cluster Chemical Abundances and Mapping Survey: VI. Galactic Chemical Gradient Analysis from APOGEE DR17
• Metallicity Structure in the Milky Way Disk Revealed by Galactic HII Regions
• Oxygen, sulfur, and iron radial abundance gradients of classical Cepheids across the Galactic thin disk
• The role of radial migration in open cluster and field star populations with Gaia dr3
• Efficient radial migration by giant molecular clouds in the first several hundred Myr after the stellar birth

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