New Pipeline for Efficient Analysis of Large Spectroscopic Samples of OB Stars

TL;DR

This paper introduces a new spectroscopic pipeline that efficiently analyzes large samples of OB stars using advanced models, addressing challenges like nebular contamination and binarity, and is integrated into the VISTA/4MOST pipeline.

Contribution

A novel spectroscopic analysis pipeline utilizing large grids of FASTWIND models, capable of homogeneous analysis of massive stars and incorporating model errors.

Findings

Good agreement with previous temperature and gravity measurements

Nebular contamination and binarity pose challenges for automatic analysis

Pipeline successfully applied to large datasets from VLT spectroscopy

Abstract

We present a new spectroscopic pipeline designed to analyse large numbers of hot massive stars homogeneously. The pipeline has been developed to utilise large grids of FASTWIND non-LTE, line blanketed models in which spherical geometry is adopted, and uniquely incorporates model errors. The pipeline has been applied to three contemporary datasets involving Very Large Telescope spectroscopy of OB stars in the Magellanic Clouds, namely the VLT FLAMES Tarantula Survey (VFTS), XShooting-ULLYSES (XShootU) and Binaries at Low Metallicity (BLOeM). We find satisfactory agreement with previous detailed temperatures and surface gravities, although strong nebular contamination, binarity and disk emission from OBe stars are problematic for automatic pipelines, requiring visual inspection of fits. The tool has been incorporated into the pipeline for the VISTA/4MOST pipeline.