Low Metallicity Indicates that the Hypervelocity Star HE 0437-5439 was Ejected from the LMC

Abstract

We measure the metallicity of the unusual hypervelocity star HE 0437-5439 from high resolution spectroscopy to be half-solar. We determine a spectral type of B2 IV-III for the star and derive an effective temperature Teff= 21,500 +/- 1,000 K and a surface gravity log(g) = 3.7 +/- 0.2 (cgs). We also present BV time series photometry and find the star to be non-variable at the 0.02 mag level. We refine the magnitude of the hypervelocity star to V=16.36+/-0.04 mag, with a color B-V=-0.23+/-0.03 mag, confirming its early-type nature. Our metallicity result establishes the origin of HE 0437-5439 in the Large Magellanic Cloud and implies the existence of a massive black hole somewhere in this galaxy.

12 pages, 3 figures, 1 table; accepted to ApJL. Added 2 coauthors & full abundance analysis. Results are strengthened

References in corpus (21)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• A method for optimal image subtraction
• Discovery of an Unbound Hyper-Velocity Star in the Milky Way Halo
• The VLT-FLAMES survey of massive stars: Surface chemical compositions of B-type stars in the Magellanic Clouds
• A-type Supergiant Abundances in the SMC: Probes of Evolution
• HE 0437-5439 -- an unbound hyper-velocity main-sequence B-type star
• Chemical Abundances of Luminous Cool Stars in the Galactic Center from High-Resolution Infrared Spectroscopy
• A Fast Algorithm for Cosmic Rays Removal from Single Images
• The First Stellar Abundance Measurements in the Galactic Center: the M Supergiant IRS 7
• Metallicity in the Galactic Center: The Arches cluster
• Stellar Iron Abundances at the Galactic Center
• HAT Variability Survey in the High Stellar Density "Kepler Field" with Millimagnitude Image Subtraction Photometry
• The Interplay between Star Formation and the Nuclear Environment of our Galaxy: Deep X-ray Observations of the Galactic Center Arches and Quintuplet Clusters
• The stellar content of the Hamburg/ESO survey. I. Automated selection of DA white dwarfs
• B-type Supergiants in the SMC: Chemical compositions and comparison of static and unified models
• Hypervelocity Stars III. The Space Density and Ejection History of Main Sequence Stars from the Galactic Center
• Pristine CNO abundances from Magellanic Cloud B stars I. The LMC cluster NGC 2004 with UVES
• C II abundances in early-type stars: solution to a notorious non-LTE problem
• Variability of Young Massive Stars in the Galactic Super Star Cluster Westerlund 1
• The Hypervelocity Star SDSS J090745.0+024507 is a Short-Period Variable
• Hypervelocity A & B Stars should be slow rotators

Cited by in corpus (24)

• Kinematics of the old stellar population at the Galactic Center
• On the origin of high-velocity runaway stars
• Hypervelocity Stars: From the Galactic Center to the Halo
• MMT Hypervelocity Star Survey
• Velocity Dispersion Profile of the Milky Way Halo
• Runaway and hypervelocity stars in the Galactic halo: Binary rejuvenation and triple disruption
• A hypervelocity star with a Magellanic origin
• Binary dynamics near a massive black hole
• The First Hypervelocity Star from the LAMOST Survey
• High velocity stars from close interaction of a globular cluster and a super massive black hole
• The Anisotropic Spatial Distribution of Hypervelocity Stars
• Hypervelocity stars in the Gaia era: Runaway B stars beyond the velocity limit of classical ejection mechanisms
• Proper Motions and Trajectories for 16 Extreme Runaway and Hypervelocity Stars
• On the spatial distribution and the origin of hypervelocity stars
• A Galactic Center Origin for HE 0437-5439, the Hypervelocity Star near the Large Magellanic Cloud
• Hypervelocity Stars from the Andromeda Galaxy
• 'Slow' and Fast Rotators among Hypervelocity Stars
• The Nature of Hypervelocity Stars and the Time Between Their Formation and Ejection
• The Galactic potential and the asymmetric distribution of hypervelocity stars
• An Upper Limit on the Mass of a Central Black Hole in the Large Magellanic Cloud from the Stellar Rotation Field
• Origin of a massive hyper-runaway subgiant star LAMOST-HVS1 -- implication from Gaia and follow-up spectroscopy
• Supernovae without host galaxy? - Hypervelocity stars in foreign galaxies
• Hypervelocity star candidates from Gaia DR2 and DR3 proper motions and parallaxes
• Threading the Magellanic Needle: Hypervelocity Stars Trace the Past Location of the LMC