Investigating episodic mass loss in evolved massive stars

Author:

Bonanos A. Z.ORCID,Tramper F.ORCID,de Wit S.ORCID,Christodoulou E.ORCID,Muñoz Sanchez G.ORCID,Antoniadis K.ORCID,Athanasiou S.ORCID,Maravelias G.ORCID,Yang M.ORCID,Zapartas E.ORCID

Abstract

Context. Episodic mass-loss events such as giant eruptions in luminous blue variables or pre-supernova eruptions in red supergiants drastically alter the evolutionary path of a massive star, resulting in a rich and complex circumstellar environment and IR excess. However, the incidence of these events, and hence their importance in massive star evolution, remains unknown. Aims. The ASSESS project (Episodic Mass Loss in Evolved Massive Stars: Key to Understanding the Explosive early Universe) aims to determine the role of episodic mass loss in the evolution of massive stars. As a first step, we constructed a catalog of spectroscopically identified dusty, evolved massive stars in ten southern galaxies for which Spitzer point-source catalogs are available. The resulting catalog may be used to identify stars that have undergone an episodic mass-loss event. The target galaxies span a range of metallicities, Z = 0.06–1.6 Z, allowing for the investigation of a potential metallicity dependence. Methods. We conducted multi-object spectroscopy of dusty massive star candidates in ten target galaxies using the Very Large Telescope. We obtained 763 spectra from WLM, NGC 55, NGC 247, NGC 253, NGC 300, NGC 1313, NGC 3109, Sextans A, M83, and NGC 7793. The targets were selected using their Spitzer photometry, by prioritizing targets with a strong IR excess, which indicates the presence of hot dust. We determined a spectral classification for each target. Additionally, we used archival images from the Hubble Space Telescope (HST), available for 150 of our targets, to provide a visual classification for 80 targets, as a star, cluster, or galaxy. Results. We provide a catalog of 541 spectroscopically classified sources that includes 185 massive stars, of which 154 are newly classified massive stars. The catalog contains 129 red supergiants, 27 blue supergiants, 10 yellow supergiants, 4 luminous blue variable candidates, 7 supergiant B[e] stars, and 8 emission-line objects. Evidence for circumstellar dust is found in 24% of these massive stars, based on their IR colors. We report a success rate of 28% for identifying massive stars from our observed spectra, while the average success rate of our priority system for selecting evolved massive stars is 36%. Additionally, the catalog contains 21 background galaxies (including active galactic nuclei and quasars), 10 carbon stars, and 99 H II regions. We measured the line ratios [N II]/Hα and [S II]/Hα for 76 H II regions and 36 other spectra with nebular emission lines, thereby identifying eight sources with shocked emission. Conclusions. We present the largest catalog of evolved massive stars and in particular of red supergiants in nearby galaxies at low Z beyond the Local Group. The brightest and reddest of these are candidates for episodic mass loss. The fraction of dusty massive stars observed with respect to the initial selection is ~30%. We expect this catalog to trigger follow-up studies and pave the way for a comprehensive study of the eruptive late stages of massive star evolution in the era of the James Webb Space Telescope and the new survey telescopes (e.g., the Euclid mission, Nancy Grace Roman Space Telescope, and Vera C. Rubin Observatory).

Funder

European Research Council

Hellenic Foundation for Research and Innovation

Publisher

EDP Sciences

Cited by 2 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3