The Corona-Australis star-forming region: New insights on its formation history from detailed stellar and disk analysis

Abstract

The star-forming complex of Corona Australis (CrA) is one of the closest and most isolated molecular clouds. It belongs to a chain of clusters that show age gradients with distance from the galactic plane. We aim to provide suggestions regarding its formation history by examining the stellar and disk populations, stellar multiplicity, and interstellar absorption. We made a census of stars and disks using Gaia DR3 and infrared data. Interstellar absorption in the direction of each star was derived by comparing SpTy from the literature and Gaia colors. Stellar multiplicity analysis accounts for both direct observation of visual companions (Gaia data and high-contrast imaging) and indirect detection of the presence of companions (eclipsing and spectroscopic binaries, and astrometry). The properties of the disks were obtained from the slopes of the spectral energy distributions. As found in previous studies, the CrA complex can be divided into two regions: a younger region (CrA-Main: 3+/-1Myr) and an older one (CrA-North: 6.7+/-0.3Myr), slightly younger than previously thought. While CrA-Main still appears bound to the gas, CrA-North is unbound and expanding. The stars that belong to CrA-North were in the most compact configuration 3.72Myr ago. At that time, CrA-Main and CrA-North were much closer to each other than they appear now. The fraction of disk-bearing stars is higher in Main than in North, as also expected due to the younger age of CrA-Main. We propose a formation history scenario for the CrA-complex. It started between 15 and 18 Myr ago with SNe explosions in the Upper Centaurus-Lupus complex, followed by a quiescent phase with little star formation. A star formation episode about 7Myr ago formed CrA-North stars. About 3.7Myr ago, a second SN explosion south of CrA-North triggered star formation in CrA-Main. This last SN might have been the origin of the pulsar RX J1856.5-3754.

arXiv comment19 pages, 17 figures, 2 online tables

References in corpus (56)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Gaia mission
• Gaia Data Release 3: Summary of the content and survey properties
• The Transiting Exoplanet Survey Satellite
• Embedded Clusters in Molecular Clouds
• Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
• Gaia Data Release 2: The astrometric solution
• galpy: A Python Library for Galactic Dynamics
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Explosion Mechanisms of Core-Collapse Supernovae
• SB9: The Ninth Catalogue of Spectroscopic Binary Orbits
• Slow Star Formation in Dense Gas: Evidence and Implications
• A Revised Age for Upper Scorpius and The Star-Formation History Among the F-Type Members of the Scorpius-Centaurus OB Association
• Observations of IC348: The Disk Population at 2-3 Million Years
• Unresolved stellar companions with Gaia DR2 astrometry
• Magnetic Inhibition of Convection and the Fundamental Properties of Low-Mass Stars. III. A Consistent 10 Myr Age for the Upper Scorpius OB Association
• Gaia Data Release 3: Stellar multiplicity, a teaser for the hidden treasure
• Stellar and substellar companions from Gaia EDR3 -- Proper motion anomaly and resolved common proper motion pairs
• A Compendium of Distances to Molecular Clouds in the Star Formation Handbook
• The relation between the most-massive star and its parental star cluster mass
• The energy and momentum input of supernova explosions in structured and ionised molecular clouds
• Ionizing Photon Emission Rates from O- and Early B-type Stars and Clusters
• A Revised Parallax and its Implications for RX J185635-3754
• The Updated Multiple Star Catalog
• Gaia DR3 astrometric orbit determination with Markov Chain Monte Carlo and Genetic Algorithms. Systems with stellar, substellar, and planetary mass companions
• The Spitzer Survey of Interstellar Clouds in the Gould Belt. III. A Multi-Wavelength View of Corona Australis
• The star formation history of the Sco-Cen association. Coherent star formation patterns in space and time
• Astrometric Identification of Nearby Binary Stars I: Predicted Astrometric Signals
• ALMA survey of Class II protoplanetary disks in Corona Australis: a young region with low disk masses
• The stellar IMF from Isothermal MHD Turbulence
• Deficit of wide binaries in the eta Chamaeleontis young cluster
• Cluster Difference Imaging Photometric Survey. I. Light Curves of Stars in Open Clusters from TESS Sectors 6 & 7
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- I. Search for exoplanets and variable stars in the field of 47 Tuc
• Fermi LAT study of cosmic-rays and the interstellar medium in nearby molecular clouds
• Significance Mode Analysis (SigMA) for hierarchical structures. An application to the Sco-Cen OB association
• Corona-Australis DANCe. I. Revisiting the census of stars with Gaia-DR2 data
• The Distance to the Isolated Neutron Star RX J0720.4-3125
• Protostars, multiplicity, and disk evolution in the Corona Australis region: A Herschel Gould Belt Study
• The dense cores and filamentary structure of the molecular cloud in Corona Australis. Herschel SPIRE and PACS observations from the Herschel Gould Belt Survey
• 2MASS wide field extinction maps: V. Corona Australis
• The Single-Cloud Star Formation Relation
• Multiplicity of young stars in and around R Corona Australis
• Protostars and stars in the Coronet cluster: Age, evolution, and cluster structure
• Unveiling the star formation history of the Upper Scorpius association through its kinematics
• Evolutionary tracks, ejecta, and ionizing photons from intermediate-mass to very massive stars with PARSEC
• The Corona Australis star formation complex is accelerating away from the Galactic plane
• Most nearby young star clusters formed in three massive complexes
• Searching for substellar companions of young isolated neutron stars
• The physical properties of Cluster Chains
• The origin of R CrA variability: A complex triple system hosting a disk
• Two decades of X-ray observations of the isolated neutron star RX J1856.5-3754: detection of thermal and non-thermal hard X-rays and refined spin-down measurement
• Multiples among B stars in the Scorpius-Centaurus association
• The Highly-Eccentric Detached Eclipsing Binaries in ACVS and MACC
• Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): Characterization of the young star T CrA and its circumstellar environment
• A study of the frequency and characteristics of stellar companions and Jupiter-like planets in nearby open clusters
• The eclipsing binary TY CrA revisited: What near-IR light curves tell us

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• Planet-forming disks and their environment across regions and time from the full NIR census
• Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): V721 CrA and BN CrA have wide and structured disks in polarised IR