A 5 per cent measurement of the Hubble-Lemaître constant from Type II supernovae

Abstract

The most stringent local measurement of the Hubble-Lemaître constant from Cepheid-calibrated Type Ia supernovae (SNe Ia) differs from the value inferred via the cosmic microwave background radiation (Planck+ΛCDM) by ∼5σ. This so-called Hubble tension has been confirmed by other independent methods, and thus does not appear to be a possible consequence of systematic errors. Here, we continue upon our prior work of using Type II supernovae to provide another, largely independent method to measure the Hubble-Lemaître constant. From 13 SNe II with geometric, Cepheid, or tip of the red giant branch (TRGB) host-galaxy distance measurements, we derive H$_0= 75.4^{+3.8}_{-3.7}$ km s-1 Mpc-1 (statistical errors only), consistent with the local measurement but in disagreement by ∼2.0σ with the Planck+ΛCDM value. Using only Cepheids (N = 7), we find H$_0 = 77.6^{+5.2}_{-4.8}$ km s-1 Mpc-1, while using only TRGB (N = 5), we derive H$_0 = 73.1^{+5.7}_{-5.3}$ km s-1 Mpc-1. Via 13 variants of our data set, we derive a systematic uncertainty estimate of 1.5 km s-1 Mpc-1. The median value derived from these variants differs by just 0.3 km s-1 Mpc-1 from that produced by our fiducial model. Because we only replace SNe Ia with SNe II - and we do not find statistically significant difference between the Cepheid and TRGB H0 measurements - our work reveals no indication that SNe Ia or Cepheids could be the sources of the 'H0 tension.' We caution, however, that our conclusions rest upon a modest calibrator sample; as this sample grows in the future, our results should be verified.