文章基本信息

标题：Infrared and sub-mm observations of outbursting young stars with Herschel and Spitzer ★ ★★
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作者：A. Postel ; M. Audard ; E. Vorobyov 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2019
卷号：631
页码：1-35
DOI：10.1051/0004-6361/201935601
语种：English
出版社：EDP Sciences
摘要：Context.Episodic accretion plays an important role in the evolution of young stars. Although it has been under investigation for a long time, the origin of such episodic accretion events is not yet understood.Aims.We investigate the dust and gas emission of a sample of young outbursting sources in the infrared to get a better understanding of their properties and circumstellar material, and we use the results in a further work to model the objects.Methods.We usedHerscheldata, from our PI program of 12 objects and complemented with archival observations to obtain the spectral energy distributions (SEDs) and spectra of our targets. We report here the main characteristics of our sample, focussing on the SED properties and on the gas emission lines detected in the PACS and SPIRE spectra.Results.The SEDs of our sample show the diversity of the outbursting sources, with several targets showing strong emission in the far-infrared from the embedded objects. Most of our targets reside in a complex environment, which we discuss in detail. We detected several atomic and molecular lines, in particular rotational CO emission from several transitions fromJ= 38−37 toJ= 4−3. We constructed rotational diagrams for the CO lines, and derived in three domains of assumed local thermodynamic equilibrium (LTE) temperatures and column densities, ranging mainly between 0−100 K and 400−500 K. We confirm correlation in our sample between intense COJ= 16−15 emission and the column density of the warm domain of CO, N(warm). We notice a strong increase in luminosity of HH 381 IRS and a weaker increase for PP 13 S, which shows the beginning of an outburst.
关键词：Key wordsenstars: formationstars: protostarsstars: pre-main sequenceprotoplanetary disksaccretion, accretion disksinfrared: stars