Lithium and beryllium in the Gaia-Enceladus galaxy

  title={Lithium and beryllium in the Gaia-Enceladus galaxy},
  author={Paolo Molaro and Gabriele Cescutti and X. Fu},
  journal={Monthly Notices of the Royal Astronomical Society},
Data from Gaia DR2 and The Apache Point Observatory Galactic Evolution Experiment surveys revealed a relatively new component in the inner Galactic halo, which is likely the dynamical remnant of a disrupted dwarf galaxy named Gaia-Enceladus that collided with the Milky Way about 10 Gyr ago. This merging event offers an extraordinary opportunity to study chemical abundances of elements in a dwarf galaxy, since they are generally hampered in external galaxies. Here, we focus on 7Li and 9Be in… 

Figures and Tables from this paper

The evolution of Lithium: implications of a universal Spite plateau
The cosmological 7Li problem consists in explaining why the primordial Li abundance, as predicted by the standard Big Bang nucleosynthesis theory with constraints from WMAP and Planck, is a factor of
The GALAH survey: accreted stars also inhabit the Spite plateau
The European Space Agency (ESA) Gaia mission has enabled the remarkable discovery that a large fraction of the stars near the solar neighbourhood are debris from a single in-falling system, the
The GALAH survey: Lithium-rich giant stars require multiple formation channels
We investigate the properties of 1306 red giant stars with high photospheric abundances of lithium observed by the GALAH, K2-HERMES and TESS-HERMES surveys, and discuss them in the context of
Inhomogeneity in the early Galactic chemical enrichment exposed by beryllium abundances in extremely metal-poor stars
Abundances of beryllium in metal-poor stars scale linearly with metallicity down to [Fe/H] ~ -3.0. In the stars where Be has been detected at this extremely metal-poor regime, an increased abundance
Detecting weak beryllium lines with CUBES
Beryllium is a light element with one single stable isotope, 9 Be, which is a pure product of cosmic-ray spallation in the interstellar medium. Beryllium abundances in late-type stars can be used in
Light Elements in the Universe
Due to their production sites, as well as to how they are processed and destroyed in stars, the light elements are excellent tools to investigate a number of crucial issues in modern astrophysics:
Reconstructing the Last Major Merger of the Milky Way with the H3 Survey
Several lines of evidence suggest that the Milky Way underwent a major merger at z ∼ 2 with the Gaia-Sausage-Enceladus (GSE) galaxy. Here we use H3 Survey data to argue that GSE entered the Galaxy on
The GALAH+ survey: Third data release
The recent exponential increase in spectroscopic, astrometric & photometric data has highlighted the scientific opportunities afforded by obtaining an ensemble of chemical element abundances for
The S2 Stream: the shreds of a primitive dwarf galaxy.*
The S2 stream is a kinematically cold stream that is plunging downwards through the Galactic disc. It may be part of a hotter and more diffuse structure called the Helmi stream. We present a
An Unsupervised Method for Identifying X-enriched Stars Directly from Spectra: Li in LAMOST
Stars with peculiar element abundances are important markers of chemical enrichment mechanisms. We present a simple method, tangent space projection (TSP), for the detection of X-enriched stars, for


The lithium content of omega Centauri. New clues to the cosmological Li problem from old stars in external galaxies
A discrepancy has emerged between the cosmic lithium abundance inferred by the WMAP satellite measurement coupled with the prediction of the standard big-bang nucleosynthesis theory, and the constant
Beryllium abundances and star formation in the halo and in the thick disk
Context. Beryllium is a pure product of cosmic ray spallation. This implies a relatively simple evolution in time of the beryllium abundance and suggests its use as a time-like observable. Aims. Our
We derive atmospheric parameters and lithium abundances for 671 stars and include our measurements in a literature compilation of 1381 dwarf and subgiant stars. First, a “lithium desert” in the
Observation of interstellar lithium in the low-metallicity Small Magellanic Cloud
Observations of interstellar 7Li in the low-metallicity gas of the Small Magellanic Cloud, a nearby galaxy with a quarter the Sun’s metallicity, are reported, showing an alternative constraint on the primordial abundance and cosmic evolution of lithium that is not susceptible to the in situ modifications that may affect stellar atmospheres.
Galactic fly-bys: New source of lithium production
Observations of low-metallicity halo stars have revealed a puzzling result: the abundance of \li7 in these stars is at least three times lower than their predicted primordial abundance. It is unclear
Lithium abundance in a turnoff halo star on an extreme orbit
The lithium abundance in turnoff stars of the old population of our Galaxy is remarkably constant in the metallicity interval -2.8\textless{}[Fe/H] \textless{}-2.0, defining a plateau. The Li
The cosmological lithium problem outside the Galaxy: the Sagittarius globular cluster M54
The cosmological Li problem is the observed discrepancy between Li abundance (A(Li)) measured in Galactic dwarf, old and metal-poor stars (traditionally assumed to be equal to the initial value
Lithium in the closest satellite of our Milky Way
Recently, we studied the chemical evolution of lithium in the thin disc of the Milky Way. We found that the best agreement with the observed Li abundances in the thin disc is obtained considering
A giant stream of metal-rich stars in the halo of the galaxy M31
The discovery of a giant stream of metal-rich stars within the halo of the nearest large galaxy, M31 (the Andromeda galaxy), demonstrates that the epoch of galaxy building still continues, albeit at a modest rate, and that tidal streams may be a generic feature of galaxy haloes.
Beryllium in Disk and Halo Stars: Evidence for a Beryllium Dispersion in Old Stars
The study of Be in stars of differing metal content can elucidate the formation mechanisms and the Galactic chemical evolution of the light element, Be. We have obtained high-resolution, high