X-Raying the Beating Heart of a Newborn Star: Rotational Modulation of High-energy Radiation from V1647 Ori
Hamaguchi, Kenji; Petre, Robert; Kastner, Joel H.; Richmond, Michael; Weintraub, David A.; Grosso, Nicolas; Teets, William K.; Principe, David
United States, France
Abstract
We report a periodicity of ~1 day in the highly elevated X-ray emission from the protostar V1647 Ori during its two recent multiple-year outbursts of mass accretion. This periodicity is indicative of protostellar rotation at near-break-up speed. Modeling of the phased X-ray light curve indicates that the high-temperature (~50 MK), X-ray-emitting plasma, which is most likely heated by accretion-induced magnetic reconnection, resides in dense (gsim 5 × 1010 cm-3), pancake-shaped magnetic footprints where the accretion stream feeds the newborn star. The sustained X-ray periodicity of V1647 Ori demonstrates that such protostellar magnetospheric accretion configurations can be stable over timescales of years.