2001/01/04 by J. Carr, John S. Carr, Robert D. Mathieu +2 · 2 citations
Chemical Engineering · Physics and Astronomy · #Advanced Combustion Engine Technologies #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/320071
to be published in The Astrophysical Journal
arxiv created 2001/01/04 · openalex publication_date 2001/04/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present the discovery of CO fundamental ro-vibrational emission from the classical T Tauri spectroscopic binary DQ Tau. The high-resolution infrared echelle spectra reveal emission lines from both the v=1 and v=2 vibrational levels with line widths of roughly 70 km s-1. The average CO excitation temperature is approximately 1200 K. We model the spectra as arising from gas in Keplerian rotation about the center-of-mass of the binary. The disk model requires gas with an average surface density of 5 x 10-4 g cm-2 that extends outward to 0.5 ± 0.1 AU and inward to at least 0.1 AU from the center-of-mass. The radial extent for the emitting gas is close to the predicted size of the gap in the DQ Tau accretion disk that is expected to be dynamically cleared by the binary. We interpret these results, and previous modeling of DQ Tau's spectral energy distribution, as evidence for a small amount ( ~ 10-10 M ‚ ) of diffuse material residing within the optically-thin disk gap. Thus dynamical clearing has not been completely efficient in the DQ Tau binary. We suggest that the material is associated with a flow from the circumbinary disk which feeds the ongoing accretion at the stellar surfaces. Subject Headings: accretion, accretion disks--- binaries: spectroscopic--- stars: pre-mainsequence