Modeling of CO Rovibrational Line Emission of HD 141569

Abstract

HD 141569 is a Herbig Ae/Be star that straddles the boundary between the transition disks and debris disks. It is a low dust mass disk that reveals numerous structural elements (e.g., gaps and rings) that may point to young planets. It also exhibits a reservoir of CO gas observed at both millimeter and IR wavelengths. Previous observations reported a possible asymmetry in the CO gas emission. Herein the IR rovibrational emission lines are analyzed and modeled both spectroscopically and spectroastrometrically. We find emission features from both ¹²CO and ¹³CO isotopologues heated to a temperature of approximately 200 K in the radial extent of 13-60 au. We do not see evidence of the previously reported asymmetry in CO emission, our results being consistent with a Keplerian, axisymmetric emitting region. This raises the question of whether the emission profile may be evolving in time, possibly as a result of an orbiting feature in the inner disk such as a planet.