A localized kinematic structure detected in atomic carbon emission spatially coincident with a proposed protoplanet in the HD 163296 disk

TL;DR

This study reports the detection of a localized bipolar kinematic structure in the HD 163296 disk's atomic carbon emission, suggesting possible protoplanet-related activity or disk winds, distinct from known stellar jets or molecular winds.

Contribution

It presents the first observation of a localized kinematic feature in atomic carbon emission potentially linked to a protoplanet or disk wind in HD 163296.

Findings

Detected a bipolar kinematic structure in C I emission at 48 au.

The structure's velocity exceeds Keplerian motion, indicating non-disk origin.

The atomic nature suggests a strong UV source or outflow activity.

Abstract

Over the last five years, studies of the kinematics in protoplanetary disks have led to the discovery of new protoplanet candidates and several structures linked to possible planet-disk interactions. We detect a localized kinematic bipolar structure in the HD 163296 disk present inside the deepest dust gap at 48 au from atomic carbon line emission. HD 163296's stellar jet and molecular winds have been described in detail in the literature; however, the kinematic anomaly in C I emission is not associated with either of them. Further, the velocity of the kinematic structure points indicates a component fast enough to differentiate it from the Keplerian profile of the disk; and its atomic nature hints at a localized UV source strong enough to dissociate CO and launch a C I outflow, or a strong polar flow from the upper layers of the disk. By discarding the stellar jet and previously observed molecular winds, we explore different sources for this kinematic feature in C I emission that could be associated with a protoplanet inflow/outflow, or disk winds.