Comparison between the CO(1–0) and H I lines. All spectra are normalized to their respective continuum. The blue curve is the H I absorption, observed in 1992 with the VLA by Carilli et al. (1992) with channels 2.57 km s⁻¹, and the red curve is from this work (H I spectrum obtained in 2020 with 6 km s⁻¹ channels). Superposed on the CO(1–0) spectrum observed in 1996 (black) from Wiklind & Combes (1997) is a CO(1–0) spectrum (green) obtained with the Institut de Radioastronomie Millimétrique (IRAM) interferometer in 2008, showing no variation.