Spectroscopy of Candidate Members of the Sco-Cen Complex

TL;DR

This study spectroscopically analyzed 285 candidate members of the Sco-Cen complex, confirming youth signatures in most and providing a comprehensive catalog of 2274 objects with spectral types and youth evidence.

Contribution

It offers the first large-scale spectroscopic confirmation and classification of candidate members in Sco-Cen, refining membership and stellar properties.

Findings

269 candidates show youth signatures confirming membership

Constructed a catalog of 2274 candidate members with spectral data

Reclassified some objects as stars rather than brown dwarfs based on spectral types

Abstract

We present spectroscopy of 285 previously identified candidate members of populations in the Sco-Cen complex, primarily Ophiuchus, Upper Sco, and Lupus. The spectra are used to measure spectral types and diagnostics of youth. We find that 269 candidates exhibit signatures of youth in our spectra or previous data, which is consistent with their membership in Sco-Cen. We have constructed compilations of candidate members of Ophiuchus, Upper Sco, and Lupus that have spectral classifications and evidence of youth, which contain a total of 2274 objects. In addition, we have used spectra from previous studies to classify three sources in Ophiuchus that have been proposed to be protostellar brown dwarfs: ISO Oph 70, 200, and 203. We measure spectral types of early M from those data, which are earlier than expected for young brown dwarfs based on evolutionary models (>=M6.5) and instead are indicative of stellar masses (~0.6 Msun).