Measuring the Hubble constant with Type Ia supernovae as near-infrared standard candles

Abstract

The most precise local measurements of $H_0$ rely on observations of Type Ia supernovae (SNe Ia) coupled with Cepheid distances to SN Ia host galaxies. Recent results have shown tension comparing $H_0$ to the value inferred from CMB observations assuming $Λ$CDM, making it important to check for potential systematic uncertainties in either approach. To date, precise local $H_0$ measurements have used SN Ia distances based on optical photometry, with corrections for light curve shape and colour. Here, we analyse SNe Ia as standard candles in the near-infrared (NIR), where intrinsic variations in the supernovae and extinction by dust are both reduced relative to the optical. From a combined fit to 9 nearby calibrator SNe with host Cepheid distances from Riess et al. (2016) and 27 SNe in the Hubble flow, we estimate the absolute peak $J$ magnitude $M_J = -18.524\;\pm\;0.041$ mag and $H_0 = 72.8\;\pm\;1.6$ (statistical) $\pm$ 2.7 (systematic) km s$^{-1}$ Mpc$^{-1}$. The 2.2 $\%$ statistical uncertainty demonstrates that the NIR provides a compelling avenue to measuring SN Ia distances, and for our sample the intrinsic (unmodeled) peak $J$ magnitude scatter is just $\sim$0.10 mag, even without light curve shape or colour corrections. Our results do not vary significantly with different sample selection criteria, though photometric calibration in the NIR may be a dominant systematic uncertainty. Our findings suggest that tension in the competing $H_0$ distance ladders is likely not a result of supernova systematics that could be expected to vary between optical and NIR wavelengths, like dust extinction. We anticipate further improvements in $H_0$ with a larger calibrator sample of SNe Ia with Cepheid distances, more Hubble flow SNe Ia with NIR light curves, and better use of the full NIR photometric data set beyond simply the peak $J$-band magnitude.

Figures (6)

• Figure 1: The peak $J$ absolute magnitude distribution for the calibrator SN Ia sample, based on the Cepheid distances of Riess2016. The data have been corrected for Milky Way extinction and K-corrections, but no further light curve shape or colour correction is applied.
• Figure 2: A comparison of the calibrator and Hubble-flow samples in host-galaxy morphology, host-galaxy reddening, and optical light-curve decline rate. Blue circles show the Hubble-flow sample $J$-band Hubble-diagram residuals (left axis), while red squares show the calibrator absolute $J$ magnitudes (right axis). The open circles indicate three fast-declining SN Ia that are excluded from our fiducial sample as outliers. These plots are used to define sample cuts only. Distances are based on the $J$-band photometry alone, with no corrections from these diagnostic parameters.
• Figure 3: Hubble diagram for our fiducial sample of 27 Hubble-flow SN Ia.
• Figure 4: Distribution and covariances of the model parameters for our fiducial sample. The uncertainties are statistical only, with the median value and 16th and 84th percentile differences listed. As discussed in the text, $a_J$ is not a fit parameter; it is calculated from the other parameters for each sample. This plot uses the corner package by FM17.
• Figure 5: Gaussian Process Fits for SNe in the calibration sample. The errorbars are smaller than the point sizes in most cases. On the x-axis, the days from $J$-band maximum are in the observer frame.