Probing the cold and warm molecular gas in the Whirlpool Galaxy: Herschel SPIRE-FTS observations of the central region of M51 (NGC 5194)

We present Herschel Spectral and Photometric Imaging Receiver (SPIRE)-Fourier Transform Spectrometer (FTS) intermediate-sampled mapping observations of the central ∼8 kpc (∼150 arcsec) of M51, with a spatial resolution of 40 arcsec. We detect four 12CO transitions (J = 4–3 to J = 7–6) and the [C i] 3P2–3P1 and 3P1–3P0 transitions. We supplement these observations with ground-based observations of 12CO J = 1–0 to J = 3–2 and perform a …