A WISE Survey of Circumstellar disks in the Upper Scorpius Association

TL;DR

This study identifies and classifies circumstellar disks around members of the Upper Scorpius association using mid-infrared data from WISE and Spitzer, revealing many previously unreported disks and their evolutionary stages.

Contribution

It provides a comprehensive catalog of disk-bearing members in Upper Sco and classifies their disk evolutionary stages using combined infrared data.

Findings

Identified 185 new likely members with disks in Upper Sco.

Classified 484 members with disks into various evolutionary stages.

Reported 179 previously unreported disks, including full and evolved types.

Abstract

We have performed a survey for new members of the Upper Sco association that have circumstellar disks using mid-infrared photometry from the Wide-field Infrared Survey Explorer (WISE). Through optical and near-infrared spectroscopy, we have confirmed 185 candidates as likely members of Upper Sco with spectral types ranging from mid-K to M9. They comprise ~36% of the known disk-bearing members of the association. We also have compiled all available mid-infrared photometry from WISE and the Spitzer Space Telescope for the known members of Upper Sco, resulting in a catalog of data for 1608 objects. We have used these data to identify the members that exhibit excess emission from disks and we have classified the evolutionary stages of those disks with criteria similar to those applied in our previous studies of Taurus and Upper Sco. Among 484 members with excesses in at least one band (excluding five Be stars), we classify 296 disks as full, 66 as evolved, 19 as transitional, 22 as evolved or transitional, and 81 as evolved transitional or debris. Many of these disks have not been previously reported, including 129 full disks and 50 disks that are at more advanced evolutionary stages.