KROSS-SAMI: A Direct IFS Comparison of the Tully-Fisher Relation Across 8 Gyr Since $z \approx 1$

TL;DR

This study compares the Tully-Fisher relations of galaxies at redshifts around 1 and 0 using direct IFS data, revealing that when data quality is matched, the relations are consistent over 8 billion years for star-forming disk galaxies.

Contribution

It provides a direct, bias-controlled comparison of Tully-Fisher relations across 8 Gyr, highlighting the importance of data quality matching in such analyses.

Findings

No significant zero-point evolution in TFR for star-forming disks over 8 Gyr.

Differences in TFR slopes and scatter are driven by data quality effects.

Matching data quality reveals consistent galaxy growth mechanisms across epochs.

Abstract

We construct Tully-Fisher relations (TFRs), from large samples of galaxies with spatially-resolved H$\alpha$ emission maps from the K-band Multi-Object Spectrograph (KMOS) Redshift One Spectroscopic Survey (KROSS) at $z\approx1$. We compare these to data from the Sydney-Australian-Astronomical-Observatory Multi-object Integral-Field Spectrograph (SAMI) Galaxy Survey at $z\approx0$. We stringently match the data quality of the latter to the former, and apply identical analysis methods and sub-sample selection criteria to both to conduct a direct comparison of the absolute $K$-band magnitude and stellar mass TFRs at $z\approx1$ and $z\approx0$. We find that matching the quality of the SAMI data to that of KROSS results in TFRs that differ significantly in slope, zero-point and (sometimes) scatter in comparison to the corresponding original SAMI relations. These differences are in every case as large or larger than the differences between the KROSS $z\approx1$ and matched SAMI $z\approx0$ relations. Accounting for these differences, we compare the TFRs at $z\approx1$ and $z\approx0$. For disk-like, star-forming galaxies we find no significant difference in the TFR zero-points between the two epochs. This suggests the growth of stellar mass and dark matter in these types of galaxies is intimately linked over this $\approx8$ Gyr period.