Emission-line stars in the LMC: the Armagh survey, and a metacatalogue

TL;DR

This paper provides precise modern astrometry for 801 emission-line objects in the LMC from the Armagh survey, enabling accurate cross-matching with digital surveys and compiling a comprehensive metacatalogue of 1675 candidate H-alpha-emission stars.

Contribution

It offers the first sub-arcsecond astrometry for these objects and creates a detailed, cross-matched metacatalogue to facilitate future research.

Findings

Achieved sub-arcsecond astrometry for all major LMC spectroscopic surveys.

Compiled a comprehensive metacatalogue of 1675 emission-line star candidates.

Resolved many identification ambiguities in primary sources.

Abstract

[Aims] Accurate astrometry is required to reliably cross-match 20th-century photographic catalogues against 21st-century digital surveys. The present work provides modern-era identifications and astrometry for the 801 emission-line objects "of stellar appearance" in the Armagh survey (the largest of its nature to date). [Methods] Targets have been individually identified in digital images using the Armagh Atlas and, in most cases, unambiguously matched to entries in the UCAC astrometric catalogues. [Results] Astrometry with sub-arcsecond precision is now available for all the major photographic spectroscopic surveys of the LMC. The results are used to compile an annotated metacatalogue of 1675 individual, spectroscopically identified candidate H-alpha-emission stars, including detailed cross-matching between catalogues, and resolving many (though not all) identification ambiguities in individual primary sources.