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Alma Luminous Star catalogue IV: A Massive star census in the Magellanic Clouds

J. A. Molina-Calzada, J. Maíz Apellániz

TL;DR

ALS IV delivers a comprehensive census of massive stars in the Magellanic Clouds by defining massive stars as those with $>8 M_\odot$ and assembling OB stars, supergiants, WRs, and related luminous types. It combines Gaia DR3 photometry/astrometry with Simbad literature classifications and augments with UBV photometry and infrared data from VISTA and 2MASS to maximize completeness. A two-stage filtering approach applies Gaia astrometric/photometric cuts and cross-matches with Simbad, producing LG/SG/BG (LMC) samples and analogous sets for the SMC and Magellanic Bridge, with additional multiwavelength and variability-based cleaning to remove contaminants. Final LS/SS/BS subsets, pending spectral verification, will be refined through further photometric and spectroscopic checks to yield a robust massive-star catalog for MCs, enabling detailed studies of their structure and dynamics. The resulting resource is poised to enhance investigations of the Clouds, the Bridge, and massive-star demographics across this nearby galactic environment.

Abstract

The fourth part of the Alma Luminous Star catalogue (ALS IV) aims to create the most comprehensive sample of massive stars in the Magellanic Clouds (MCs). By combining Gaia DR3 with Simbad and complementing this information with other photometric and spectroscopic catalogues, we select the massive stars in this region. To achieve this, we apply filters in photometry, combining different bands, as well as in variability and spectral types from the literature. With this approach, we will obtain one of the most complete samples of massive stars in the MCs, which can be used both to study the Clouds and the Magellanic Bridge, as well as the massive stars they contain.

Alma Luminous Star catalogue IV: A Massive star census in the Magellanic Clouds

TL;DR

ALS IV delivers a comprehensive census of massive stars in the Magellanic Clouds by defining massive stars as those with and assembling OB stars, supergiants, WRs, and related luminous types. It combines Gaia DR3 photometry/astrometry with Simbad literature classifications and augments with UBV photometry and infrared data from VISTA and 2MASS to maximize completeness. A two-stage filtering approach applies Gaia astrometric/photometric cuts and cross-matches with Simbad, producing LG/SG/BG (LMC) samples and analogous sets for the SMC and Magellanic Bridge, with additional multiwavelength and variability-based cleaning to remove contaminants. Final LS/SS/BS subsets, pending spectral verification, will be refined through further photometric and spectroscopic checks to yield a robust massive-star catalog for MCs, enabling detailed studies of their structure and dynamics. The resulting resource is poised to enhance investigations of the Clouds, the Bridge, and massive-star demographics across this nearby galactic environment.

Abstract

The fourth part of the Alma Luminous Star catalogue (ALS IV) aims to create the most comprehensive sample of massive stars in the Magellanic Clouds (MCs). By combining Gaia DR3 with Simbad and complementing this information with other photometric and spectroscopic catalogues, we select the massive stars in this region. To achieve this, we apply filters in photometry, combining different bands, as well as in variability and spectral types from the literature. With this approach, we will obtain one of the most complete samples of massive stars in the MCs, which can be used both to study the Clouds and the Magellanic Bridge, as well as the massive stars they contain.
Paper Structure (4 sections, 4 figures)

This paper contains 4 sections, 4 figures.

Table of Contents

  1. Introduction
  2. Data
  3. Filtering process
  4. Conclusions and Future Work

Figures (4)

  • Figure 1: Sky map of the Gaia sample for the MCs (left), the defined regions (center; the intensity scales differ for each color), and the filtered LG, SG, and BG samples (right).
  • Figure 2: Photometric cut applied to the CMD of Gaia DR3, after astrometric filtering, for the LMC (left), SMC (center), and MB (right).
  • Figure 3: Flow chart of the cross-match between Gaia DR3 (filtered astrometrically and photometrically) and Simbad (filtered by stellar objects) for the LMC.
  • Figure 4: Parallax (left) and proper motion (center and right) distributions (log scale) for the combined LG sample. Light shading: low uncertainties. Dashed line: median value. The structures seen in the proper motions reflect their internal motions.