A Chandra Census of C2D YSOS: Evolution of X-ray Emission

TL;DR

This study analyzes X-ray emissions from approximately 109 young stellar objects, revealing that X-ray energy decreases with age and column density, suggesting coronal cooling over a few million years.

Contribution

It provides the first comprehensive analysis of X-ray properties across different classes of young stellar objects, highlighting the evolution of X-ray energy with age and accretion activity.

Findings

X-ray energy decreases with age and column density.

Deeply embedded protostars emit mainly hard X-rays.

X-ray emission declines as the corona cools over time.

Abstract

We present an analytical study of a large sample of ~109 young stellar objects in the X-ray. Our objects were detected in X-ray independent of age. Unexpectedly, the X-ray energy is somewhat correlated with the ages. It decreases with time and with column density, while it should increase. We conclude that the youngest protostars, Class 0/I, emit X-rays in the 1-8 keV band. The deeply embedded sources with the strongest accretion activity are detected in the hard-band (> 2keV) only. Due to extinction, their soft X-rays are not detected. To explain the decline in energy, we suggest that within a timescale of few Myrs the corona cools down via the accretion material.