A Uniform Type Ia Supernova Distance Ladder with the Zwicky Transient Facility: Absolute Calibration Based on the Tip of the Red Giant Branch Method

Suhail Dhawan, Ariel Goobar, Joel Johansson, In Sung Jang, Mickael Rigault, Luke Harvey, Kate Maguire, Wendy L. Freedman, Barry F. Madore, Mathew Smith, Jesper Sollerman, Young Lo Kim, Igor Andreoni, Eric C. Bellm, Michael W. Coughlin, Richard Dekany, Matthew J. Graham, Shrinivas R. Kulkarni, Russ R. Laher, Michael S. MedfordJames D. Neill, Guy Nir, Reed Riddle, Ben Rusholme

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


The current Cepheid-calibrated distance ladder measurement of H 0 is reported to be in tension with the values inferred from the cosmic microwave background (CMB), assuming standard cosmology. However, some tip of the red giant branch (TRGB) estimates report H 0 in better agreement with the CMB. Hence, it is critical to reduce systematic uncertainties in local measurements to understand the Hubble tension. In this paper, we propose a uniform distance ladder between the second and third rungs, combining Type Ia supernovae (SNe Ia) observed by the Zwicky Transient Facility (ZTF) with a TRGB calibration of their absolute luminosity. A large, volume-limited sample of both calibrator and Hubble flow SNe Ia from the same survey minimizes two of the largest sources of systematics: host-galaxy bias and nonuniform photometric calibration. We present results from a pilot study using the existing TRGB distance to the host galaxy of ZTF SN Ia SN 2021rhu (aka ZTF21abiuvdk) in NGC7814. Combining the ZTF calibrator with a volume-limited sample from the first data release of ZTF Hubble flow SNe Ia, we infer H 0 = 76.94 ± 6.4 km s−1 Mpc−1, an 8.3% measurement. The error budget is dominated by the single object calibrating the SN Ia luminosity in this pilot study. However, the ZTF sample includes already five other SNe Ia within ∼20 Mpc for which TRGB distances can be obtained with the Hubble Space Telescope. Finally, we present the prospects of building this distance ladder out to 80 Mpc with James Webb Space Telescope observations of more than 100 ZTF SNe Ia.

Original languageEnglish (US)
Article number185
JournalAstrophysical Journal
Issue number2
StatePublished - Aug 1 2022

Bibliographical note

Funding Information:
Based on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. Z.T.F. is supported by the National Science Foundation under grant No. AST-2034437 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, IN2P3, France, the University of Warwick, the University of Bochum, and Northwestern University. Operations are conducted by COO, IPAC, and UW. SEDMachine is based upon work supported by the National Science Foundation under grant No. 1106171. S.D. acknowledges support from the Marie Curie Individual Fellowship under grant ID 890695 and a Junior Research Fellowship at Lucy Cavendish College. A.G. acknowledges support from the Swedish Research Council under Dnr VR 2020-03444 and the Swedish National Space Board. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 759194—USNAC). Y.-L.K. acknowledges support by the Science and Technology Facilities Council [grant No. ST/V000713/1]. W.L.F. acknowledges support from program #13691 provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NASA 5-26555. M.W.C acknowledges support from the National Science Foundation with grant numbers PHY-2010970 and OAC-2117997. This work was supported by the GROWTH Marshal project (Kasliwal et al. ) funded by the National Science Foundation under grant No. 1545949.

Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.


  • Hubble constant
  • Observational cosmology
  • Type Ia supernovae


Dive into the research topics of 'A Uniform Type Ia Supernova Distance Ladder with the Zwicky Transient Facility: Absolute Calibration Based on the Tip of the Red Giant Branch Method'. Together they form a unique fingerprint.

Cite this