%0 Generic %1 anderson2019towards %A Anderson, Richard I. %D 2019 %K tifr %T Towards a 1% Measurement of the Hubble Constant: Accounting for Time Dilation in Variable Star Light Curves %U http://arxiv.org/abs/1909.10847 %X Assessing the significance and implications of the recently established Hubble tension requires the comprehensive identification, quantification, and mitigation of uncertainties and/or biases affecting $H_0$ measurements. Here, we investigate the previously overlooked distance scale bias resulting from the interplay between redshift and Leavitt laws in an expanding Universe: Redshift-Leavitt bias (RLB). Redshift dilates oscillation periods of pulsating stars residing in supernova-host galaxies relative to periods of identical stars residing in nearby (anchor) galaxies. Multiplying dilated $P$ with Leavitt Law slopes leads to underestimated absolute magnitudes, overestimated distance moduli, and a systematic error on $H_0$. Emulating the SH0ES distance ladder, we estimate an associated $H_0$ bias of $(0.27 0.01)$% and obtain a corrected $H_0 = (73.70 1.40) km s^-1 Mpc^-1$. RLB becomes increasingly relevant as distance ladder calibrations pursue greater numbers of ever more distant galaxies hosting both Cepheids (or Miras) and type-Ia supernovae. The measured periods of oscillating stars can readily be corrected for heliocentric redshift (e.g. of their host galaxies) in order to ensure $H_0$ measurements free of RLB.

@misc{anderson2019towards, abstract = {Assessing the significance and implications of the recently established Hubble tension requires the comprehensive identification, quantification, and mitigation of uncertainties and/or biases affecting $H_0$ measurements. Here, we investigate the previously overlooked distance scale bias resulting from the interplay between redshift and Leavitt laws in an expanding Universe: Redshift-Leavitt bias (RLB). Redshift dilates oscillation periods of pulsating stars residing in supernova-host galaxies relative to periods of identical stars residing in nearby (anchor) galaxies. Multiplying dilated $\log{P}$ with Leavitt Law slopes leads to underestimated absolute magnitudes, overestimated distance moduli, and a systematic error on $H_0$. Emulating the SH0ES distance ladder, we estimate an associated $H_0$ bias of $(0.27 \pm 0.01)$% and obtain a corrected $H_0 = (73.70 \pm 1.40) \rm{km s^{-1} Mpc^{-1}}$. RLB becomes increasingly relevant as distance ladder calibrations pursue greater numbers of ever more distant galaxies hosting both Cepheids (or Miras) and type-Ia supernovae. The measured periods of oscillating stars can readily be corrected for heliocentric redshift (e.g. of their host galaxies) in order to ensure $H_0$ measurements free of RLB.}, added-at = {2019-09-25T07:16:51.000+0200}, author = {Anderson, Richard I.}, biburl = {https://www.bibsonomy.org/bibtex/21177842163c9d6e68e105d0f76c91476/citekhatri}, interhash = {52a764a4584124f1053076fdf68eedbb}, intrahash = {1177842163c9d6e68e105d0f76c91476}, keywords = {tifr}, note = {cite arxiv:1909.10847Comment: Accepted for publication in Astronomy & Astrophysics. 6 pages, 5 figures, 1 table}, timestamp = {2019-09-25T07:16:51.000+0200}, title = {Towards a 1% Measurement of the Hubble Constant: Accounting for Time Dilation in Variable Star Light Curves}, url = {http://arxiv.org/abs/1909.10847}, year = 2019 }