Search for a distance-dependent Baryonic Tully-Fisher Relation at low redshifts

TL;DR

This study investigates whether the Baryonic Tully-Fisher relation (BTFR) varies with distance at low redshifts and finds no significant evidence for such a dependence, challenging previous claims of a transition at 9 and 17 Mpc.

Contribution

The paper introduces an analysis of the BTFR with parameters that vary with distance and finds these variations are statistically insignificant, providing a more consistent view of the relation at low redshifts.

Findings

No significant variation in BTFR parameters with distance.

BTFR remains consistent across different distance subsamples.

Previous claims of a transition at 9 and 17 Mpc are not supported.

Abstract

A recent work (arXiv:2104.14481) has found a statistically significant transition in the Baryonic Tully-Fisher relation (BTFR) using low redshift data ($z<0.1$), with the transitions occurring at about 9 and 17 Mpc. Motivated by this finding, we carry out a variant of this analysis by fitting the data to an augmented BTFR, where both the exponent as well as normalization constant vary as a function of distance. We find that both the exponent and normalization constant show only a marginal variation with distance, and are consistent with a constant value, to within $2\sigma$. We also checked to see if there is a statistically significant difference between the BTFR results after bifurcating the dataset at distances of 9 and 17 Mpc. We find that almost all the sets of subsamples obey the BTFR with $\chi^2$/dof close to 1 and the best-fit parameters consistent across the subsamples. Only the subsample with $D<17$ Mpc shows a marginal discrepancy (at $1.75\sigma$) with respect to the BTFR. Therefore, we do not find any evidence for statistically significant differences in the BTFR at distances of 9 and 17 Mpc.