IRS Spectra of Debris Disks in the Scorpius-Centaurus OB Association

TL;DR

This study analyzes infrared spectra of young stars in the ScoCen OB association to model their debris disks, revealing mass-dependent dust distribution and potential planet formation constraints.

Contribution

It provides the first detailed modeling of debris disks around a large sample of young stars in ScoCen, highlighting dust distribution patterns and planet formation implications.

Findings

Dust around lower mass stars is closer in than around higher mass stars.

Most systems can be modeled with one or two dust belts.

Gaps in two-belt systems suggest possible planet locations.

Abstract

We analyze Spitzer IRS spectra of 110 B-, A-, F-, and G-type stars with optically thin infrared excess in the Scorpius-Centaurus (ScoCen) OB association. The age of these stars ranges from 11-17 Myr. We fit the infrared excesses observed in these sources by Spitzer IRS and Spitzer MIPS to simple dust models according to Mie theory. We find that nearly all the objects in our study can be fit by one or two belts of dust. Dust around lower mass stars appears to be closer in than around higher mass stars, particularly for the warm dust component in the two-belt systems, suggesting mass-dependent evolution of debris disks around young stars. For those objects with stellar companions, all dust distances are consistent with trunction of the debris disk by the binary companion. The gaps between several of the two-belt systems can place limits on the planets that might lie between the belts, potentially constraining the mass and locations of planets that may be forming around these stars.