Rapid Dissipation of Protoplanetary Disks in Ophiuchus

TL;DR

This study estimates the ages of young stars in Ophiuchus and finds that their protoplanetary disks dissipate faster than in Taurus, suggesting environmental factors influence disk evolution timescales.

Contribution

It provides a new age determination for stars in Ophiuchus and quantifies the inner disk lifetime, highlighting environmental dependence of disk dissipation.

Findings

Average star age is 0.7 Myr.

Inner disk lifetime is approximately 1.2 Myr.

Disk dissipation occurs faster in Ophiuchus than in Taurus.

Abstract

We present the results of an age determination study for pre-main sequence stars in the Ophiuchus molecular cloud. The ages of eight pre-main sequence stars were estimated from surface gravities derived from high-resolution spectroscopy. The average age of the target stars was 0.7 Myr. By comparing the individual age and the near-infrared color excess, we found that color excess decreases gradually with a constant rate and the lifetime of the inner disk was determined to be 1.2 Myr. The estimated lifetime is nearly a half of the time compared to that of the pre-main sequence stars in the Taurus molecular cloud estimated with the same method. This result indicates that the disk evolution timescale depends on the environment of the star-forming region.