Origin of X-ray emission from intermediate-mass pre-main-sequence stars

Determine the physical origin of X-ray emission from intermediate-mass pre-main-sequence stars, distinguishing among wind-driven shocks, magnetic activity intrinsic to Herbig Ae/Be stars, and unresolved active companions.

Background

The paper investigates whether X-ray emission is associated with angular-momentum loss in intermediate-mass pre-main-sequence stars in Trumpler 14. Unlike low-mass pre-main-sequence stars, these stars are not generally expected to possess strong surface magnetic fields once on the main sequence, so their X-rays may arise from several competing mechanisms.

The unresolved origin of the X-rays limits the interpretation of the observed tendency for X-ray-detected objects to rotate more slowly. Establishing whether the emission traces intrinsic magnetic activity, wind shocks, or unresolved companions is therefore necessary to determine whether X-ray-related magnetic braking contributes to the formation of slow rotators.

References

For both stars, the available observations therefore do not uniquely establish the origin of the X-ray emission.

— A comprehensive multi-wavelength study of two X-ray emitting Be stars  (2609.28719 - Anilkumar et al., 23 Sep 2026) in Section 5.3, subsection “Possibility of Unresolved Companion-induced X-ray Emission”; Conclusion

The positional consistency between the Chandra sources and the Gaia counterparts supports an association of the X-ray emission with the optical counterparts, although an unresolved low-mass companion within the spatial resolution of Chandra cannot be completely ruled out.

— A comprehensive multi-wavelength study of two X-ray emitting Be stars  (2609.28719 - Anilkumar et al., 23 Sep 2026) in Section 5.3, subsection “Possibility of Unresolved Companion-induced X-ray Emission”

The origin of X rays from intermediate-mass stars is not clear.

— Uncovering the Origin of Slow Rotators among Intermediate-Mass Stars in the Star-Forming Cluster Trumpler 14  (2609.11053 - Rao et al., 10 Sep 2026) in Section 1, Introduction