The hyperplane of early-type galaxies: using stellar population properties to increase the precision and accuracy of the fundamental plane as a distance indicator ...

• Main Authors: D'Eugenio, Francesco, Colless, Matthew, van der Wel, Arjen, Vaughan, Sam P., Said, Khaled, van de Sande, Jesse, Bland-Hawthorn, Joss, Bryant, Julia J., Croom, Scott M., Lopez-Sanchez, Angel R., Lorente, Nuria P. F., Maiolino, Roberto, Taylor, Edward N.
• Format: Text
• Language: unknown
• Published: arXiv 2024
• Subjects: Astrophysics of Galaxies astro-ph.GA; Cosmology and Nongalactic Astrophysics astro-ph.CO; FOS Physical sciences; sami
• Online Access: https://dx.doi.org/10.48550/arxiv.2406.17842; https://arxiv.org/abs/2406.17842

We use deep spectroscopy from the SAMI Galaxy Survey to explore the precision of the fundamental plane of early-type galaxies (FP) as a distance indicator for future single-fibre spectroscopy surveys. We study the optimal trade-off between sample size and signal-to-noise ratio (SNR), and investigate which additional observables can be used to construct hyperplanes with smaller intrinsic scatter than the FP. We add increasing levels of random noise (parametrised as effective exposure time) to the SAMI spectra to study the effect of increasing measurement uncertainties on the FP-and hyperplane-inferred distances. We find that, using direct-fit methods, the values of the FP and hyperplane best-fit coefficients depend on the spectral SNR, and reach asymptotic values for a mean SNR=40 Å$^{-1}$. As additional variables for the FP we consider three stellar-population observables: light-weighted age, stellar mass-to-light ratio and a novel combination of Lick indices (I$_{\rm age}$). For a SNR=45 Å$^{-1}$ ... : 24 pages, 18 figures, accepted for publication in MNRAS ...