Terrestrial Zone Debris Disk Candidates in h and chi Persei

TL;DR

This study identifies potential terrestrial zone debris disks in the h and chi Persei cluster by analyzing infrared excesses and modeling their spectral energy distributions, suggesting ongoing terrestrial planet formation.

Contribution

It demonstrates that optically-thin debris disk models from terrestrial planet formation theories explain observed infrared excesses better than thick disk models.

Findings

Infrared excesses are consistent with debris disks at 300-400 K.

Optically-thick disk models do not fit the observed data.

Debris disks may indicate terrestrial planet formation activity.

Abstract

We analyze 8 sources with strong mid-infrared excesses in the 13 Myr-old double cluster h and chi Persei. New optical spectra and broadband SEDs (0.36-8 mu_m) are consistent with cluster membership. We show that material with T ~ 300-400 K and Ld/Lstar ~ 10^-4-10^-3 produces the excesses in these sources. Optically-thick blackbody disk models - including those with large inner holes - do not match the observed SEDs. The SEDs of optically-thin debris disks produced from terrestrial planet formation calculations match the observations well. Thus, some h and chi Persei stars may have debris from terrestrial zone planet formation.