The Gaia-ESO survey: placing constraints on the origin of r-process elements

Abstract

A renewed interest about the origin of \emph{r}-process elements has been stimulated by the multi-messenger observation of the gravitational event GW170817, with the detection of both gravitational waves and electromagnetic waves corresponding to the merger of two neutron stars. Such phenomenon has been proposed as one of the main sources of the \emph{r}-process. However, the origin of the \emph{r}-process elements at different metallicities is still under debate. We aim at investigating the origin of the \emph{r}-process elements in the Galactic thin disc population. From the sixth internal data release of the \emph{Gaia}-ESO we have collected a large sample of Milky Way thin- and thick-disc stars for which abundances of Eu, O, and Mg are available. The sample consists of members of 62 open clusters, located at a Galactocentric radius from $\sim 5$ kpc to $\sim 20$ kpc in the disc, in the metallicity range $[-0.5,0.4]$ and covering an age interval from 0.1 to 7 Gy, and about 1300 Milky Way disc field stars in the metallicity range $[-1.5,0.5]$. We compare the observations with the results of a chemical evolution model, in which we varied the nucleosynthesis sources for the three considered elements. Our main result is that Eu in the thin disc is predominantly produced by sources with short lifetimes, such as magneto-rotationally driven SNe. There is no strong evidence for additional sources at delayed times. Our findings do not imply that there cannot be a contribution from mergers of neutron stars in other environments, as in the halo or in dwarf spheroidal galaxies, but such a contribution is not needed to explain Eu abundances at thin disc metallicities.

20 pages, accepted for publication in A&A

References in corpus (41)

• Multi-messenger Observations of a Binary Neutron Star Merger
• Origin of the heavy elements in binary neutron-star mergers from a gravitational wave event
• Spectroscopic identification of r-process nucleosynthesis in a double neutron star merger
• A kilonova as the electromagnetic counterpart to a gravitational-wave source
• Painting a portrait of the Galactic disc with its stellar clusters
• Identification of strontium in the merger of two neutron stars
• APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South
• Galactic Chemical Evolution and solar s-process abundances: dependence on the 13C-pocket structure
• Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars
• Current Status of r-Process Nucleosynthesis
• Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program II: Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd and Eu
• The intermediate neutron-capture process and carbon-enhanced metal-poor stars
• Young [$\alpha$/Fe]-enhanced stars discovered by CoRoT and APOGEE: What is their origin?
• The Gaia-ESO Public Spectroscopic Survey: Implementation, data products, open cluster survey, science, and legacy
• Abundance gradients in the Milky Way for alpha elements, Iron peak elements, Barium, Lanthanum and Europium
• The role of neutron star mergers in the chemical evolution of the Galactic halo
• Barium & related stars and their white-dwarf companions I. Giant stars
• VLT/FLAMES spectroscopy of red giant branch stars in the Fornax dwarf spheroidal galaxy
• Explaining the Ba, Y, Sr, and Eu abundance scatter in metal-poor halo stars: constraints to the r-process
• The Gaia-ESO Survey: processing of the FLAMES-UVES spectra
• New insights on Ba over-abundance in open clusters. Evidence for the intermediate neutron-capture process at play?
• The chemical compositions of solar twins in the open cluster M67
• A new delay time distribution for merging neutron stars tested against Galactic and cosmic data
• The Gaia-ESO Survey: a new approach to chemically characterising young open clusters
• How magnetic activity alters what we learn from stellar spectra
• The Gaia-ESO Survey: calibration strategy
• Magnetohydrodynamic Simulations of A Rotating Massive Star Collapsing to A Black Hole
• The Gaia-ESO Survey: CNO abundances in the open clusters Trumpler 20, NGC 4815, and NGC 6705
• The origin of stellar populations in the Galactic bulge from chemical abundances
• Evidence for $\gtrsim 4$ Gyr timescales of neutron star mergers from Galactic archaeology
• The Gaia-ESO Survey: Age-chemical-clock relations spatially resolved in the Galactic disc
• Origin of $\alpha$-rich young stars: clues from C, N and O
• The Gaia-ESO Survey: A new approach to chemically characterising young open clusters II. Abundances of the neutron-capture elements Cu, Sr, Y, Zr, Ba, La, and Ce
• Evidence for the accretion origin of halo stars with an extreme r-process enhancement
• Abundances of neutron-capture elements in thin- and thick-disc stars in the solar neighbourhood
• Spectroscopic study of CEMP-(s & r/s) stars- Revisiting classification criteria and formation scenarios, highlighting i-process nucleosynthesis
• Most "young" $\alpha$-rich stars have high masses but are actually old
• Heavy elements in barium stars
• The AMBRE Project: Spectrum normalisation influence on Mg abundances in the metal-rich Galactic disc
• Heavy element evolution in the inner regions of the Milky Way
• Heavy elements in old very metal-rich stars

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• The Gaia-ESO survey: mapping the shape and evolution of the radial abundance gradients with open clusters
• Origin of neutron capture elements with the Gaia-ESO survey: the evolution of s- and r-process elements across the Milky Way
• Mapping radial abundance gradients with Gaia-ESO open clusters: Evidence of recent gas accretion in the Milky Way disk
• Dynamics of baryon ejection in magnetar giant flares: implications for radio afterglows, r-process nucleosynthesis, and fast radio bursts
• Does the i-process operate at nearly solar metallicity?
• Inference of multi-channel r-process element enrichment in the Milky Way using binary neutron star merger observations
• Europium, we have a problem. Modelling r-process enrichment across Local Group galaxies
• Evolution of lithium in the disc of the Galaxy and the role of novae
• Neutron-Capture Element Signatures in Globular Clusters: Insights from the Gaia-ESO Survey