Variability in the CO ro-vibrational lines from HD163296

Abstract

We present for the first time a direct comparison of multi-epoch (2001-2002 and 2012) CO ro-vibrational emission lines from HD163296. We find that both the line shapes and the FWHM (Full Width Half Maximum) differ between these two epochs. The FWHM of the median observed line profiles are 10-25 km/s larger in the earlier epoch, and confirmed double peaks are only present in high J lines from 2001-2002. The line wings of individual transitions are similar in the two epochs making an additional central component in the later epoch a likely explanation for the single peaks and the lower FWHM. Variations in NIR brightness have been reported and could be linked to the observed variations. Additionally, we use the thermo chemical disc code ProDiMo to compare for the first time the line shapes, peak separations, FWHM, and line fluxes, to those observed. The ProDiMo model reproduces the peak separations, and low and mid J line fluxes well. The FWHM however, are over predicted and high J line fluxes are under predicted. We propose that a variable non-Keplerian component of the CO ro-vibrational emission, such as a disc wind or an episodic accretion funnel, is causing the difference between the two data sets collected at different epochs, and between model and observations. Additional CO ro-vibrational line detections (with CRIRES/VLT or NIRSPEC/Keck) or [Ne II] line observations with VISIR/VLT could help to clarify the cause of the variability.

13 pages, 10 figures, 3 tables. Accepted to MNRAS

References in corpus (14)

• Gas and Dust Emission at the Outer Edge of Protoplanetary Disks
• Parameters of Herbig Ae/Be and Vega-type stars
• Millimeter imaging of HD 163296: probing the disk structure and kinematics
• Neon Fine-Structure Line Emission By X-ray Irradiated Protoplanetary Disks
• A Tale of Two Herbig Ae stars -MWC275 and AB Aurigae: Comprehensive Models for SED and Interferometry
• Tracing the inner edge of the disk around HD 100546 with Ro-vibrational CO Emission Lines
• Variability of Disk Emission in Pre-Main Sequence and Related Stars. I. HD 31648 and HD 163296 - Isolated Herbig Ae Stars Driving Herbig-Haro Flows
• Relating jet structure to photometric variability: the Herbig Ae star HD 163296
• The HD 163296 Circumstellar Disk in Scattered Light: Evidence of Time-Variable Self-Shadowing
• Strong Near-Infrared Emission Interior to the Dust-Sublimation Radius of Young Stellar Objects MWC275 and AB Aur
• [NeII] emission line profiles from photoevaporative disc winds
• Low EUV Luminosities Impinging on Protoplanetary Disks
• The structure of disks around Herbig Ae/Be stars as traced by CO ro-vibrational emission
• Probing the accretion-ejection connection with VLTI/AMBER: High spectral resolution observations of the Herbig Ae star HD163296

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• The kinematics and excitation of infrared water vapor emission from planet-forming disks: results from spectrally-resolved surveys and guidelines for JWST spectra
• Multi-epoch Direct Imaging and Time-Variable Scattered Light Morphology of the HD 163296 Protoplanetary Disk
• A gas density drop in the inner 6 AU of the transition disk around the Herbig Ae star HD 139614: Further evidence for a giant planet inside the disk?
• Formation of Dust Rings and Gaps in Non-ideal MHD Disks Through Meridional Gas Flows
• A proposed new diagnostic for Herbig disc geometry: FWHM versus J of CO ro-vibrational lines