Modeling of CO ro-vibrational line emission of HD 141569

TL;DR

This paper models IR CO ro-vibrational emission from HD 141569, revealing symmetric, Keplerian gas distribution and questioning previous asymmetry reports, with implications for disk evolution and planet presence.

Contribution

It provides the first detailed spectroscopic and spectroastrometric modeling of CO emission in HD 141569, showing symmetric emission and challenging earlier asymmetry claims.

Findings

CO gas heated to ~200 K from 13 to 60 au

No evidence of previously reported asymmetry

Emission consistent with Keplerian, axisymmetric disk

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 (Goto et al. 2006) reported a possible asymmetry in the CO gas emission. Herein the IR ro-vibrational 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 to 60 au. We do not see evidenceof 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.