Gaia DR2 reveals a star formation burst in the disc 2-3 Gyr ago

Abstract

We use Gaia DR2 magnitudes, colours and parallaxes for stars with G<12 to explore a 15-dimensional space that includes simultaneously the initial mass function (IMF) and a non-parametric star formation history (SFH) for the Galactic disc. This inference is performed by combining the Besancon Galaxy Model fast approximate simulations (BGM FASt) and an approximate Bayesian computation algorithm. We find in Gaia DR2 data an imprint of a star formation burst 2-3 Gyr ago, in the Galactic thin disc domain, and a present star formation rate (SFR) of about 1 Msun. Our results show a decreasing trend of the SFR from 9-10 Gyr to 6-7 Gyr ago. This is consistent with the cosmological star formation quenching observed at redshifts z<1.8. This decreasing trend is followed by a SFR enhancement starting at about 5 Gyr ago and continuing until about 1 Gyr ago which is detected with high statistical significance by discarding the null hypothesis of an exponential SFH with a p-value=0.002. We estimate, from our best fit model, that about the 50% of the mass used to generate stars, along the thin disc life, was expended in the period from 5 to 1 Gyr ago. The timescale and the amount of stellar mass generated during the SFR enhancement event lead us to hypothesise that its origin, currently under investigation, is not intrinsic to the disc. Thus, an external perturbation is needed for its explanation. Additionally we find, for the thin disc, a slope of the IMF of ${\alpha }_3\approx 2$ for masses M>1.53 Msun and ${\alpha }_2\approx 1.3$ for the mass range between 0,5 and 1,53 Msun. This is the first time that we consider a non-parametric SFH for the thin disc in the Besancon Galaxy Model. This new step, together with the capabilities of the Gaia DR2 parallaxes to break degeneracies between different stellar populations, allow us to better constrain the SFH and the IMF.

arXiv comment6 pages, 3 figures. Accepted for publication to A&A letters

References in corpus (32)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• Gaia Data Release 2: The astrometric solution
• The Initial Mass Function of Stars: Evidence for Uniformity in Variable Systems
• The merger that led to the formation of the Milky Way's inner stellar halo and thick disk
• Gaia Data Release 2: Photometric content and validation
• Modelling the Galactic Interstellar Extinction Distribution in Three Dimensions
• A dynamically young and perturbed Milky Way disk
• Three Dimensional Structure of the Milky Way Disk
• Kinematics and history of the solar neighbourhood revisited
• On the frequency, intensity and duration of starburst episodes triggered by galaxy interactions and mergers
• The stellar and sub-stellar IMF of simple and composite populations
• Merger Histories of Galaxy Halos and Implications for Disk Survival
• Stellar populations in the Milky Way bulge region : Towards solving the Galactic bulge and bar shapes using 2MASS data
• 3D maps of interstellar dust in the Local Arm: using $Gaia$, 2MASS and APOGEE-DR14
• Reconstructing the star formation history of the Milky Way disc(s) from chemical abundances
• The impact of the metallicity and star formation rate on the time-dependent galaxy-wide stellar initial mass function
• Constraining the thick disc formation scenario of the Milky Way
• The Besancon Galaxy model renewed I. Constraints on the local star formation history from Tycho data
• When the Milky Way turned off the lights: APOGEE provides evidence of star formation quenching in our Galaxy
• Thickening of galactic disks through clustered star formation
• The star-formation rate density from z = 0-6
• Bar quenching in gas-rich galaxies
• The optimally-sampled galaxy-wide stellar initial mass function - Observational tests and the publicly available GalIMF code
• Recovering the star formation rate in the solar neighborhood
• Phylogeny of the Milky Way's inner disk and bulge populations: Implications for gas accretion, (the lack of) inside-out thick disk formation, and quenching
• astroABC: An Approximate Bayesian Computation Sequential Monte Carlo sampler for cosmological parameter estimation
• Towards a fully consistent Milky Way disc model - III. Constraining the initial mass function
• The emergence of the galactic stellar mass function from a non-universal IMF in clusters
• Was the Milky Way a chain galaxy? Using the IGIMF theory to constrain the thin-disk star formation history and mass
• Constraining the Thin Disc Initial Mass Function using Galactic Classical Cepheids
• An inverse method to recover the star formation history and reddening properties of a galaxy from its spectrum. Application to NGC 7714

Cited by in corpus (78)

• Gaia Early Data Release 3: The Gaia Catalogue of Nearby Stars
• Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18
• A cooling anomaly of high-mass white dwarfs
• High-precision abundances of elements in solar-type stars. Evidence of two distinct sequences in abundance-age relations
• Pressure-Regulated, Feedback-Modulated Star Formation In Disk Galaxies
• APOGEE DR16: a multi-zone chemical evolution model for the Galactic disc based on MCMC methods
• The Canada-France Imaging Survey: Reconstructing the Milky Way Star Formation History from its White Dwarf Population
• A Tale of Two Disks: Mapping the Milky Way with the Final Data Release of APOGEE
• Spectroscopic age estimates for APOGEE red-giant stars: Precise spatial and kinematic trends with age in the Galactic disc
• Unveiling the time evolution of chemical abundances across the Milky Way disk with APOGEE
• Characterizing epochs of star formation across the Milky Way disc using age-metallicity distributions of GALAH stars
• The most massive stars in very young star clusters with a limited mass: Evidence favours significant self-regulation in the star formation processes
• On the origin of the Galactic thin and thick discs, their abundance gradients and the diagnostic potential of their abundance ratios
• 1I/'Oumuamua as an N2 ice fragment of an exo-pluto surface. II. Generation of N2 ice fragments and the origin of 'Oumuamua
• Evidence for $\gtrsim 4$ Gyr timescales of neutron star mergers from Galactic archaeology
• The phase spiral in Gaia DR3
• The stellar Initial Mass Function of the solar neighbourhood revealed by Gaia
• Buoyant crystals halt the cooling of white dwarf stars
• The Milky Way's Shell Structure Reveals the Time of a Radial Collision
• Axion Astrophysics
• 1I/'Oumuamua as an N2 ice fragment of an exo-Pluto surface: I. size and compositional constraints
• The effect of the environment-dependent IMF on the formation and metallicities of stars over the cosmic history
• The star cluster age function in the Galactic disc with Gaia DR2: Fewer old clusters and a low cluster formation efficiency
• A self-consistent dynamical model of the Milky Way disc adjusted to Gaia data
• Star formation history of the solar neighbourhood as told by Gaia
• The TIME Table: Rotation and Ages of Cool Exoplanet Host Stars
• A bottom-heavy initial mass function for the likely-accreted blue-halo stars of the Milky Way
• Deciphering the evolution of the Milky Way discs: Gaia APOGEE Kepler giant stars and the Besançon Galaxy Model
• Local stellar formation history from the 40 pc white dwarf sample
• Dissecting the Gaia HR diagram within 200 pc
• A Swing of the Pendulum: The Chemodynamics of the Local Stellar Halo Indicate Contributions from Several Radial Merger Events
• The Salpeter IMF and its descendants
• Mapping radial abundance gradients with Gaia-ESO open clusters: Evidence of recent gas accretion in the Milky Way disk
• Constraints on the star formation histories of galaxies in the Local Cosmological Volume
• New Insight into the stellar mass function of Galactic globular clusters
• Paleo-Detectors for Galactic Supernova Neutrinos
• Bioverse: a simulation framework to assess the statistical power of future biosignature surveys
• The APO-K2 Catalog. II. Accurate Stellar Ages for Red Giant Branch Stars across the Milky Way
• The Cooling of Massive White Dwarfs from Gaia EDR3
• The evolution of lithium in FGK dwarf stars: The Li rotation connection and the Li desert
• Accurate X-ray Timing in the Presence of Systematic Biases With Simulation-Based Inference
• A revisited study of Cepheids in open clusters in the Gaia era
• The impact of metallicity on nova populations
• Unveiling the past evolution of the progenitor of the Helmi streams
• Testing Earth-like atmospheric evolution on exo-Earths through oxygen absorption: required sample sizes and the advantage of age-based target selection
• Galactic Chemical Evolution Models Favor an Extended Type Ia Supernova Delay-Time Distribution
• The Mass Budget Necessary to Explain `Oumuamua as a Nitrogen Iceberg
• The White Dwarfs of the Old, Solar Metallicity Open Star Cluster Messier 67: Properties and Progenitors
• Eta-Earth Revisited II: Deriving a Maximum Number of Earth-like Habitats in the Galactic Disk
• The galaxy-wide stellar initial mass function in the presence of cluster-to-cluster IMF variations
• Towards a fully consistent Milky Way disk model -- IV. The impact of Gaia DR2 and APOGEE
• Predicting the water content of interstellar objects from galactic star formation histories
• Modelling chemical clocks -- Theoretical evidences of the space and time evolution of [s/alpha] in the Galactic disc with Gaia-ESO survey
• A Crystallizing White Dwarf in a Sirius-Like Quadruple System
• Characterising abundance-age relations of GALAH stars using oxygen-enhanced stellar models
• r-Process enrichment in the Galactic halo characterized by nucleosynthesis variation in the ejecta of coalescing neutron star binaries
• Recent star formation episodes in the Galaxy: impact on its chemical properties and the evolution of its abundance gradient
• Stellar collisions in globular clusters: Constraints on the initial mass function of the first generation of stars
• Rocks, Water and Noble Liquids: Unfolding the Flavor Contents of Supernova Neutrinos
• The formation history of the Milky Way disc with high-resolution cosmological simulations
• Joint inference of the Milky Way star formation history and IMF from Gaia all-sky $G<13$ data
• Ba Enrichment in Gaia MS+WD Binaries: Tracing $s$-Process Element Production
• Potential Impact of the Sagittarius Dwarf Galaxy on the Formation of Young O-rich Stars
• Towards a fully consistent Milky Way disk model V. The disk model for 4 $-$ 14 kpc
• Understanding the Baryon Cycle: Fueling Star Formation via Inflows in Milky Way-like Galaxies
• Fundamental Tests of White Dwarf Cooling Physics with Wide Binaries
• The bi-modal ${}^7$Li distribution of the Milky Way's thin-disk dwarf stars: The role of Galactic-scale events and stellar evolution
• Stellar Migration and Chemical Enrichment in the Milky Way Disc: A Hybrid Model
• The origin of ultramassive white dwarfs: hints from Gaia EDR3
• The New Astronomical Frontier of Interstellar Objects
• Chemodynamical Ages of Small-Scale Kinematic Structures of the Galactic Disc in the Solar Neighborhood from ~250,000 K and M Dwarfs
• The effects of Galactic model uncertainties on LISA observations of double neutron stars
• Searching for the nature of stars with debris disks and planets
• Solar twins in Gaia DR3 GSP-Spec I. Building a large catalog of Solar twins with ages
• Solar twins in Gaia DR3 GSP-Spec II. Age distribution and its implications for the Sun's migration
• Gauging the Impact of Cosmic Ray Feedback on the Stellar Initial Mass Function
• A new method to retrieve the star formation history from white dwarf luminosity functions -- an application to the Gaia catalogue of nearby stars
• Observational imprints of tidal internal gravity wave dissipation in star-planet systems