Red Be stars in the Magellanic Clouds?

Abstract

We revisit the subject of Be star candidates towards the Magellanic Clouds, previously studied by the authors using SPM4 proper motions. We obtain GAIA DR2 parallaxes and proper motions for 2357 and 994 LMC and SMC Be candidates, respectively. Parallaxes and proper motions vs. color V-I easily reveal the presence of the redder galactic contaminant foreground, as concluded in our previous work, but this time we do find a few red Be stars candidates consistent with being true Magellanic objects. A membership assessment to each Magellanic Cloud is done for each Be candidate, based on the distribution of their parallaxes and proper motions. From a compilation of published catalogues of spectroscopically confirmed Be stars, we found that 40 (LMC) and 64 (SMC) of these Be candidates, are in fact Be stars. Near infrared IRSF JHKs magnitudes were obtained for about 70% the Be stars candidates with GAIA DR2 astrometric data. Mid-infrared SAGE IRAC 3.6, 4.5, 5.8 and 8.0 $\mu$m magnitudes were obtained for about 85% as well. 6 LMC and 7 SMC confirmed Be stars show optical, near- or mid-infrared colours redder than what has been typically measured for Classical Be stars. Several of the Be candidates follow those redder-than-expected colours distributions suggesting the existence of more red Magellanic Be stars.

arXiv commentSlight change in title, two new more authors, 15 pages, 12 figures, accepted by MNRAS

References in corpus (34)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• Gaia Data Release 2: using Gaia parallaxes
• Spitzer Survey of the Large Magellanic Cloud, Surveying the Agents of a Galaxy's Evolution (SAGE) I: Overview and Initial Results
• Gaia Data Release 2: Kinematics of globular clusters and dwarf galaxies around the Milky Way
• Classical Be Stars: Rapidly Rotating B Stars with Viscous Keplerian Decretion Disks
• Evidence for a systematic offset of -80 micro-arcseconds in the Gaia DR2 parallaxes
• Surveying the Agents of Galaxy Evolution in the Tidally-Stripped, Low Metallicity Small Magellanic Cloud (SAGE-SMC). I. Overview
• Herbig Ae/Be Stars in nearby OB associations
• NLTE Monte Carlo Radiative Transfer: I. The Thermal Properties of Keplerian Disks around Classical Be Stars
• Confirmation of the $Gaia$ DR2 parallax zero-point offset using asteroseismology and spectroscopy in the $Kepler$ field
• High-Mass X-ray binaries in the Small Magellanic Cloud
• The Southern Proper Motion Program IV. The SPM4 Catalog
• Effects of metallicity, star-formation conditions, and evolution in B and Be stars. II: Small Magellanic Cloud, field of NGC 330
• Populations of rotating stars III. SYCLIST, the new Geneva Population Synthesis code
• On Be Star Candidates and Possible Blue Pre-Main Sequence Objects in the Small Magellanic Cloud
• Non-LTE Monte Carlo Radiative Transfer: II. Non-Isothermal Solutions for Viscous Keplerian Disks
• The life cycles of Be viscous decretion discs: fundamental disc parameters of 54 SMC Be stars
• Self-Lensing Models of the LMC
• The life cycles of Be viscous decretion discs: time-dependent modelling of infrared continuum observations
• Cyclic Variability of the Circumstellar Disc of the Be Star $\zeta$ Tau. II. Testing the 2D Global Disc Oscillation Model
• Properties of the $\delta$ Scorpii Circumstellar Disk from Continuum Modeling
• Proper Motion Study of the Magellanic Clouds using SPM material
• Achernar: Rapid Polarization Variability as Evidence of Photospheric and Circumstellar Activity
• The life cycles of Be viscous decretion discs: The case of ω CMa
• A slitless spectroscopic survey for Halpha emission-line objects in SMC clusters
• The Infrared Continuum Sizes of Be Star Disks
• Emission-line stars discovered in the UKST H-alpha survey of the Large Magellanic Cloud; Part 1: Hot stars
• A Parameter Study of Classical Be Star Disk Models Constrained by Optical Interferometry
• Effects of Grain Size on the Spectral Energy Distribution of Dusty Circumstellar Envelopes
• The Circumstellar Discs of Be Stars
• Study of candidate Be stars in the Magellanic Clouds using NIR photometry and optical spectroscopy
• Multitechnique testing of the viscous decretion disk model I. The stable and tenuous disk of the late-type Be star $\beta$ CMi
• Proper motion separation of Be star candidates in the Magellanic Clouds and the Milky Way

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