MINDS. The DR Tau disk I: combining JWST-MIRI data with high-resolution CO spectra to characterise the hot gas

The MRS mode of the JWST-MIRI instrument has been shown to be a powerful tool to characterise the molecular gas emission of the inner region of planet-forming disks. Here, we analyse the spectrum of the compact T-Tauri disk DR Tau, which is complemented by high spectral resolution (R 60000-90000) CO ro-vibrational observations. Various molecular species, including CO, CO_2, HCN, and C_2H_2 are detected in the JWST-MIRI spectrum, for which excitation temperatures of T 325-900 K are retrieved using LTE slab models. The high-resolution CO observations allow for a full treatment of the line profiles, which show evidence for two components of the main isotopologue, ^12CO: a broad component tracing the Keplerian disk and a narrow component tracing a slow disk wind. Rotational diagrams yield excitation temperatures of T>725 K for CO, with consistently lower temperatures found for the narrow components, suggesting that the disk wind is launched from a larger distance. The inferred excitation temperatures for all molecules suggest that CO originates from the highest atmospheric layers close to the host star, followed by HCN and C_2H_2, which emit, together with ^13CO, from slightly deeper layers, whereas the CO_2 originates from even deeper inside or further out in the disk. Additional analysis of the ^12CO line wings hint at a misalignment between the inner (i 20 degrees) and outer disk (i 5 degrees). Finally, we emphasise the need for complementary high-resolution CO observations, as in combination with the JWST-MIRI observations they can be used to characterise the CO kinematics and the physical and chemical conditions of the other observed molecules with respect to CO.