On the Origin of the Kinematical Differences Between the Stellar Halo and the Old Globular Cluster System in the Large Magellanic Cloud

Abstract

We discuss structural and kinematical properties of the stellar halo and the old globular cluster system (GCS) in the Large Magellanic Cloud (LMC) based on numerical simulations of the LMC formation. We particularly discuss the observed possible GCS's rotational kinematics (V/sigma > 2) that appears to be significantly different from the stellar halo's one with a large velocity dispersion (~50 km/s). We consider that both halo field stars and old GCs can originate from low-mass subhalos virialized at high redshifts (z >6). We investigate the final dynamical properties of the two old components in the LMC's halo formed from merging of low-mass subhalos with field stars and GCs. We find that the GCS composed of old globular clusters (GCs) formed at high redshifts (z > 6) has little rotation (V/sigma ~0.4) and structure and kinematics similar to those of the stellar halo. This inconsistency between the simulated GCS's kinematics and the observed one is found to be seen in models with different parameters. This inconsistency therefore implies that if old, metal-poor GCs in the LMC have rotational kinematics, they are highly unlikely to originate from the low-mass subhalos that formed the stellar halo. We thus discuss a scenario in which the stellar halo was formed from low-mass subhalos with no/few GCs whereas the GCS was formed at the very early epoch of the LMC's disk formation via dissipative minor and major merging of gas-rich subhalos and gas infall. We suggest that there can be a threshold subhalo mass above which GCs can be formed within subhalos at high redshifts and thus that this threshold causes differences in physical properties between stellar halos and GCSs in less luminous galaxies like the LMC.

arXiv comment10 pages, 8 figures, accepted by MNRAS

References in corpus (36)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• Star Formation in Galaxies Along the Hubble Sequence
• Three Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Polarization Analysis
• Wilkinson Microwave Anisotropy Probe (WMAP) First Year Observations: TE Polarization
• Extragalactic Globular Clusters and Galaxy Formation
• A Survey of z>5.7 Quasars in the Sloan Digital Sky Survey II: Discovery of Three Additional Quasars at z>6
• New Understanding of Large Magellanic Cloud Structure, Dynamics and Orbit from Carbon Star Kinematics
• Magellanic Cloud Structure from Near-IR Surveys I: The Viewing Angles of the LMC
• Formation of omega Centauri from an ancient nucleated dwarf galaxy in the young Galactic disc
• The Efficiency of Globular Cluster Formation
• A New Look at the Large-Scale HI Structure of the LMC
• The Formation of Disk Galaxies in a Cosmological Context: Structure and Kinematics
• Formation and evolution of the Magellanic Clouds. I.Origin of structural, kinematical, and chemical properties of the Large Magellanic Cloud
• Calcium II Triplet Spectroscopy of LMC Red Giants. I. Abundances and Velocities for a Sample of Populous Clusters
• Formation of Dwarf Galaxies during the Cosmic Reionization
• Metal abundances of RR Lyrae stars in the bar of the Large Magellanic Cloud
• Star Formation Histories from HST Color-Magnitude Diagrams of Six Fields of the LMC
• AGB stars in the Magellanic Clouds. I. The C/M ratio
• Formation of the Galactic stellar halo I. Structure and kinematics
• Explaining the mysterious age gap of globular clusters in the Large Magellanic Cloud
• The Metallicity Distribution Function of Red Giants in the LMC
• Kinematic Evidence for an Old Stellar Halo in the Large Magellanic Cloud
• The Globular Cluster Systems of the Sculptor Group
• Properties of RR Lyrae stars in the Inner Regions of the Large Magellanic Cloud
• Structure of the Galactic Stellar Halo Prior to Disk Formation
• Kinematics of Tidal Debris from Omega Centauri's Progenitor Galaxy
• The Stellar Halo in the Large Magellanic Cloud: Mass, Luminosity, and Microlensing Predictions
• The Globular Cluster System of the Virgo Dwarf Elliptical Galaxy VCC 1087
• Properties of RR Lyrae stars in the inner regions of the Large Magellanic Cloud. II. The extended sample
• Formation of giant globular cluster G1 and the origin of the M31 stellar halo
• Formation of the Galactic disk globular clusters in early dissipative minor merging
• Formation of the Galactic stellar halo. Origin of the metallicity-eccentricity relation
• The Galactic globular cluster system as a fossil record of reionization
• On the Origin of Mass--Metallicity Relations, Blue Tilts, and Scaling Relations for Metal-poor Globular Cluster Systems
• RR Lyrae stars in the inner Large Magellanic Cloud: Halo-like location with a disk-like distribution
• Were the LMC Globular Clusters Formed in a Disk?

Cited by in corpus (4)

• The age-metallicity relationship of the Large Magellanic Cloud field star population from wide-field Washington photometry
• Origin of structural and kinematical properties of the Small Magellanic Cloud
• Two kinematically distinct old globular cluster populations in the Large Magellanic Cloud
• Unearthing Foundations of a Cosmic Cathedral: Searching the Stars for M33's Halo