No evidence for protoplanetary disk destruction by OB stars in the MYStIX sample

TL;DR

This study investigates whether massive OB stars in star-forming regions destroy protoplanetary disks around nearby young stars, finding no evidence of disk depletion near such stars in the MYStIX sample, challenging previous assumptions.

Contribution

It provides the first large-scale observational test showing that OB stars do not significantly destroy protoplanetary disks in their vicinity.

Findings

No observed deficit of disk-bearing stars near O stars

Protoplanetary disks survive in massive star-forming regions

Massive stars are less hostile to disks than previously thought

Abstract

HST images of proplyds in the Orion Nebula, as well as submillimeter/radio measurements, show that the dominant O7 star Theta1 Ori C photoevaporates nearby disks around pre-main sequence stars. Theory predicts that massive stars photoevaporate disks within distances of order 0.1 pc. These findings suggest that young, OB-dominated massive H II regions are inhospitable to the survival of protoplanetary disks, and subsequently to the formation and evolution of planets. In the current work, we test this hypothesis using large samples of pre-main sequence stars in 20 massive star-forming regions selected with X-ray and infrared photometry in the MYStIX survey. Complete disk destruction would lead to a deficit of cluster members with excess in JHKs and Spitzer/IRAC bands in the vicinity of O stars. In four MYStIX regions containing O stars and a sufficient surface density of disk-bearing sources to reliably test for spatial avoidance, we find no evidence for the depletion of inner disks around pre-main sequence stars in the vicinity of O-type stars, even very luminous O2-O5 stars. These results suggest that massive star-forming regions are not very hostile to the survival of protoplanetary disks and, presumably, to the formation of planets.