The Stellar "Snake" I: Whole Structure and Properties

Abstract

To complement our previous discovery of the young snake-like structure in the solar neighborhood and reveal the structure's full extent, we build two samples of stars within the Snake and its surrounding territory from {\tt Gaia EDR3}. With the friends-of-friends algorithm, we identify 2694 and 9615 Snake member candidates from the two samples. Thirteen open clusters are embedded in these member candidates. By combining the spectroscopic data from multiple surveys, we investigate the comprehensive properties of the candidates and find that they \thj{are very likely to} belong to one sizable structure, since most of the components are well bridged in their spatial distributions, and follow a single stellar population with an age of $30-40$\,Myr and solar metallicity. This sizable structure is best explained as hierarchically primordial, and probably formed from a filamentary giant molecular cloud with unique formation history in localized regions. To analyze the dynamics of the Snake, we divide the structure into five groups according to their tangential velocities; we find that the groups are expanding at a coherent rate (${\kappa }_X\sim 3.0\times 10^{-2}\mathrm{km}{\mathrm{s}}^{-1}\mathrm{p}{\mathrm{c}}^{-1}$) along the length of the structure ($X$-direction). \thj{The corresponding expansion age ($\tau \sim 33$\,Myr) is highly consistent with the age of the Snake}. With over ten thousand member stars, the Snake is an ideal laboratory to study nearby coeval stellar formation, stellar physics, and environmental evolution over a large spatial extent.

arXiv comment18 pages, 13 figures, 1 table, submitted to MNRAS (revised according to the referee's comments)

References in corpus (77)

• Astropy: A Community Python Package for Astronomy
• The NumPy array: a structure for efficient numerical computation
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• Gaia Data Release 2: The astrometric solution
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• galpy: A Python Library for Galactic Dynamics
• The Rockstar Phase-Space Temporal Halo Finder and the Velocity Offsets of Cluster Cores
• A Hipparcos census of the nearby OB associations
• A new generation of PARSEC-COLIBRI stellar isochrones including the TP-AGB phase
• New catalogue of optically visible open clusters and candidates
• Global survey of star clusters in the Milky Way II. The catalogue of basic parameters
• A Gaia DR2 view of the Open Cluster population in the Milky Way
• Improving PARSEC models for very low mass stars
• PARSEC evolutionary tracks of massive stars up to $350M_{\odot }$ at metallicities 0.0001$\le Z\le$0.04
• The GALAH+ Survey: Third Data Release
• Rapid Formation of Molecular Clouds and Stars in the Solar Neighborhood
• A dynamically young and perturbed Milky Way disk
• New PARSEC evolutionary tracks of massive stars at low metallicity: testing canonical stellar evolution in nearby star forming dwarf galaxies
• The Formation of a Bound Star Cluster: From the Orion Nebula Cluster to the Pleiades
• The Data Reduction Pipeline for the Apache Point Observatory Galactic Evolution Experiment
• The APOGEE-2 Survey of the Orion Star Forming Complex II: Six-dimensional structure
• Galactic Rotation and Solar Motion from Stellar Kinematics
• Star and protoplanetary disk properties in Orion's suburbs
• Age determination for 269 $Gaia$ DR2 Open Clusters
• The stellar association around Gamma Velorum and its relationship with Vela OB2
• The Vela Pulsar's proper motion and parallax derived from VLBI observations
• A catalog of newly identified star clusters in GAIA DR2
• A Compendium of Distances to Molecular Clouds in the Star Formation Handbook
• Untangling the Galaxy I: Local Structure and Star Formation History of the Milky Way
• A Galactic-scale gas wave in the Solar Neighborhood
• The Sixth Data Release of the Radial Velocity Experiment (RAVE) -- I: Survey Description, Spectra and Radial Velocities
• The Kinematics of the Scorpius-Centaurus OB Association from Gaia DR1
• YBC, a stellar bolometric corrections database with variable extinction coefficients: an application to PARSEC isochrones
• Discovery of an equal-mass "twin" binary population reaching 1000+ AU separations
• Extended stellar systems in the solar neighborhood -- V. Discovery of coronae of nearby star clusters
• Young Stellar Objects in Lynds 1641: Disks, Accretion, and Star Formation History
• IN-SYNC IV - The Young Stellar Population in the Orion A Molecular Cloud
• Expanding associations in the Vela-Puppis region: 3D structure and kinematics of the young population
• The Physical Properties of Large-Scale Galactic Filaments
• OB associations and their origins
• Structure, kinematics, and ages of the young stellar populations in the Orion region
• γ^2 Velorum: Orbital Solution and Fundamental Parameter Determination with SUSI
• The Separation Distribution of Ultra-Wide Binaries across Galactic Populations
• A ring in a shell: the large-scale 6D structure of the Vela OB2 complex
• Shape parameters of Galactic open clusters
• NGC 1980 is not a foreground population of Orion: Spectroscopic survey of young stars with low extinction in Orion A
• The Gaia-ESO Survey: Asymmetric expansion of the Lagoon Nebula cluster NGC 6530 from GES and Gaia DR2
• Modelling unresolved binaries of open clusters in color-magnitude diagram. I. method and application of NGC3532
• Modeling of the Vela complex including the Vela supernova remnant, the binary system gamma2 Velorum, and the Gum nebula
• Uncovering a 260 pc wide, 35 Myr old filamentary relic of star formation
• A sextet of clusters in the Vela OB2 region revealed by Gaia
• Pre-Main sequence Turn-On as a chronometer for young clusters: NGC346 as a benchmark
• The Gaia DR2 view of the Gamma Velorum cluster: resolving the 6D structure
• A stellar relic filament in the Orion star forming region
• Time stamps of vertical phase mixing in the Galactic disk from LAMOST-Gaia stars
• An Improved HR Diagram for the Orion Trapezium Cluster
• Discovery of a 21 Myr old stellar population in the Orion complex
• Discovery of new stellar groups in the Orion complex
• A bottom-heavy initial mass function for the likely-accreted blue-halo stars of the Milky Way
• Tidal-locking-induced stellar rotation dichotomy in the open cluster NGC 2287?
• Vertical Phase Mixing across the Galactic Disk
• The Dense Filamentary Giant Molecular Cloud G23.0-0.4: Birthplace of Ongoing Massive Star Formation
• The Gaia-ESO survey: A lithium depletion boundary age for NGC 2232
• Discovery of a young stellar "snake" with two dissolving cores in the solar neighborhood
• The stellar kinematics in the solar neighborhood from LAMOST data
• The peculiar velocities in the Galactic outer disk--hints of the elliptical disk and the perturbation of the spiral structures
• The peculiar in-plane velocities in the outer disc of the Milky Way
• Collinder 135 and UBC 7: A Physical Pair of Open Clusters
• The dynamics of the γ Vel cluster and nearby Vela OB2 association
• The low mass population of the Vela OB2 association from Gaia
• Birth Sites of Young Stellar Associations and Recent Star Formation in a Flocculent Corrugated Disk
• Exploring the total Galactic extinction with SDSS BHB stars
• The filamentary structures in the CO emission toward the Milky Way disk
• Giant molecular clouds: star factories of the galaxy
• The 800pc long tidal tails of the Hyades star cluster: Possible discovery of candidate epicyclic overdensities from an open star cluster

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• Hunting for Neighboring Open Clusters with Gaia DR3: 101 New Open Clusters within 500 pc
• 3D Morphology of Open Clusters in the Solar Neighborhood with Gaia EDR3 II: Hierarchical Star Formation Revealed by Spatial and Kinematic Substructures
• Most nearby young star clusters formed in three massive complexes
• Disconnecting the Dots: Re-Examining the Nature of Stellar "Strings" in the Milky Way
• Open superclusters I: The most populated primordial groups of open clusters in the third quadrant of the Galactic disc