The Large Magellanic Cloud stellar content with SMASH: I. Assessing the stability of the Magellanic spiral arms

Abstract

The Large Magellanic Cloud (LMC) is the closest and most studied example of an irregular galaxy. Among its principal defining morphological features, its off-centred bar and single spiral arm stand out, defining a whole family of galaxies known as the Magellanic spirals (Sm). These structures are thought to be triggered by tidal interactions and possibly maintained via gas accretion. However, it is still unknown whether they are long-lived stable structures. In this work, by combining photometry that reaches down to the oldest main sequence turn-off in the colour-magnitude diagrams (CMD, up to a distance of $\sim$4.4 kpc from the LMC centre) from the SMASH survey and CMD fitting techniques, we find compelling evidence supporting the long-term stability of the LMC spiral arm, dating the origin of this structure to more than 2~Gyr ago. The evidence suggests that the close encounter between the LMC and the Small Magellanic Cloud (SMC) that produced the gaseous Magellanic Stream and its Leading Arm (LA) also triggered the formation of the LMC's spiral arm. Given the mass difference between the Clouds and the notable consequences of this interaction, we can speculate that this should have been one of their closest encounters. These results set important constraints on the timing of LMC-SMC collisions, as well as on the physics behind star formation induced by tidal encounters.

arXiv comment6 pages, 3 figures, accepted for publication in A&A letters

References in corpus (47)

• Astropy: A Community Python Package for Astronomy
• On the variation of the Initial Mass Function
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• Adaptive spatial binning of integral-field spectroscopic data using Voronoi tessellations
• Are the Magellanic Clouds on their First Passage about the Milky Way?
• The Star Formation History of the Large Magellanic Cloud
• The Role of Dwarf Galaxy Interactions in Shaping the Magellanic System and Implications for Magellanic Irregulars
• The Origin of the Magellanic Stream and Its Leading Arm
• A New Look at the Large-Scale HI Structure of the LMC
• Lopsided Spiral Galaxies and a Limit on the Galaxy Accretion Rate
• The Tidal Origin of the Magellanic Stream and the Possibility of a Stellar Counterpart
• The ACS LCID project. III. The star formation history of the Cetus dSph galaxy: a post-reionization fossil
• The Orbital Histories of Magellanic Satellites Using Gaia DR2 Proper Motions
• Lopsided spiral galaxies: evidence for gas accretion
• Ram Pressure Stripping of the Large Magellanic Cloud's Disk as a Probe of the Milky Way's Circumgalactic Medium
• SMASH - Survey of the MAgellanic Stellar History
• The ACS LCID project. V. The Star Formation History of the Dwarf Galaxy \objectname[]{LGS-3}: Clues for Cosmic Reionization and Feedback
• How Common are the Magellanic Clouds?
• The Proper Motion Field of the Small Magellanic Cloud: Kinematic Evidence for its Tidal Disruption
• Comparing the Ancient Star Formation Histories of the Magellanic Clouds
• SMASHing the LMC: A Tidally-induced Warp in the Outer LMC and a Large-scale Reddening Map
• Low Surface Brightness Imaging of the Magellanic System: Imprints of Tidal Interactions between the Clouds in the Stellar Periphery
• A model for lopsided galactic disks
• Star formation history of the Galactic bulge from deep HST imaging of low reddening windows
• Spatially resolved LMC star formation history: I. Outside in evolution of the outer LMC disk
• On the Origin of Lopsidedness in Galaxies as Determined from the Spitzer Survey of Stellar Structure in Galaxies (S4G)
• Numerical simulations of interacting gas-rich barred galaxies. Vertical impact of small companions
• Discovery of a Large Stellar Periphery Around the Small Magellanic Cloud
• Substructures and tidal distortions in the Magellanic stellar periphery
• The Spatially-Resolved Star Formation History of the M31 Outer Disc
• Lopsidedness in WHISP galaxies: II. Morphological lopsidedness
• The VMC Survey - X. Cepheids, RR Lyrae stars and binaries as probes of the Magellanic System's structure
• The kinematics of lopsided galaxies
• Lopsided Galaxies, Weak Interactions and Boosting the Star Formation Rate
• The VMC Survey -- XXXIV. Morphology of Stellar Populations in the Magellanic Clouds
• The MAGellanic Inter-Cloud project (MAGIC) I: Evidence for intermediate-age stellar populations in between the Magellanic Clouds
• SMASHing THE LMC: Mapping a Ring-like Stellar Overdensity in the LMC Disk
• Modeling the Baryon Cycle in Low Mass Galaxy Encounters: the Case of NGC 4490 & NGC 4485
• The bursty star formation history of the Fornax dwarf spheroidal galaxy revealed with the HST
• Tidally Induced Offset Disks in Magellanic Spiral Galaxies
• Tidal-induced lopsidedness in Magellanic-type galaxies
• Chemical Abundances in the Leading Arm of the Magellanic Stream
• Integrated-light analyses vs. colour-magnitude diagrams - II. Leo A, an extremely young dwarf in the Local Group
• On the nature of a shell of young stars in the outskirts of the Small Magellanic Cloud
• A New Population of Planetary Nebulae Discovered in the Large Magellanic Cloud (IV): The Outer LMC
• The origin of the LMC stellar bar: clues from the SFH of the bar and inner disk

Cited by in corpus (22)

• APOGEE Chemical Abundance Patterns of the Massive Milky Way Satellites
• Reconstructing the Disrupted Dwarf Galaxy $Gaia$-Sausage/Enceladus Using its Stars and Globular Clusters
• The synchronised dance of the Magellanic Clouds' star formation history
• Discovery of an Ultra-Faint Stellar System near the Magellanic Clouds with the DECam Local Volume Exploration (DELVE) Survey
• Chronology of our Galaxy from Gaia Colour-Magnitude Diagram-fitting (ChronoGal). I. The formation and evolution of the thin disk from the Gaia Catalogue of Nearby Stars
• The Second Data Release of the Survey of the MAgellanic Stellar History (SMASH)
• Magellanic Mayhem: Metallicities and Motions
• Exploring the diversity and similarity of radially anisotropic Milky Way-like stellar haloes: implications for disrupted dwarf galaxy searches
• The VISCACHA survey -- VII. Assembly history of the Magellanic Bridge and SMC Wing from star clusters
• The RR Lyrae Delay-Time Distribution: A Novel Perspective on Models of Old Stellar Populations
• The miniJPAS survey: The galaxy populations in the most massive cluster in miniJPAS, mJPC2470-1771
• A genuine Large Magellanic Cloud age gap star cluster
• Astrophysical properties of newly discovered Magellanic Cloud star clusters
• Spatio-temporal map of star clusters in the Magellanic Clouds using Gaia: Synchronized peaks and radial shrinkage of cluster formation
• The Magellanic Puzzle: origin of the periphery
• First evidence of a stripped star cluster from the Small Magellanic Cloud
• The 3D kinematics of stellar substructures in the periphery of the Large Magellanic Cloud
• The Local Ultraviolet to Infrared Treasury I. Survey Overview of the Broadband Imaging
• The Quest for the Missing Dust: I -- Restoring Large Scale Emission in Herschel Maps of Local Group Galaxies
• The Magellanic Edges Survey -- II. Formation of the LMC's northern arm
• J-PLUS Reconstructing the Milky Way Disc's star formation history with twelve-filter photometry
• Direct power spectral density estimation from structure functions without Fourier transforms