AGB interlopers in YSO catalogues hunted out by NEOWISE

Abstract

AGBs and YSOs often share the same domains in IR color-magnitude or color-color diagrams leading to potential mis-classification. We extracted a list of AGB interlopers from the published YSO catalogues using the periodogram analysis on NEOWISE time series data. YSO IR variability is typically stochastic and linked to episodic mass accretion. Furthermore, most variable YSOs are at an early evolutionary stage, with significant surrounding envelope and/or disk material. In contrast, AGBs are often identified by a well defined sinusoidal variability with periods of a few hundreds days. From our periodogram analysis of all known low mass YSOs in the Gould Belt, we find 85 AGB candidates, out of which 62 were previously classified as late-stage Class III YSOs. Most of these new AGB candidates have similar IR colors to O-rich AGBs. We observed 73 of these AGB candidates in the H2O, CH3OH and SiO maser lines to further reveal their nature. The SiO maser emission was detected in 10 sources, confirming them as AGBs since low mass YSOs, especially Class III YSOs, do not show such maser emission. The H2O and CH3OH maser lines were detected in none of our targets.

Accepted for publication in ApJL

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Cited by in corpus (8)

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• A Naive Bayes Classifier for identifying Class II YSOs
• Distributed YSOs in the Perseus Molecular Cloud from the Gaia and LAMOST Surveys
• The JCMT Transient Survey: Single Epoch Transients and Variability of Faint Sources
• The SPHEREx Target List of Ice Sources (SPLICES)
• The Ages of Optically Bright Sub-Clusters in the Serpens Star-Forming Region
• Probabilistic Classification of Infrared-selected targets for SPHEREx mission: In search of YSOs