The SAMI Galaxy Survey: stellar population and structural trends across the Fundamental Plane

We study the Fundamental Plane (FP) for a volume- and luminosity-limited sample of 560 early-type galaxies from the SAMI survey. Using r −band sizes and luminosities from new Multi-Gaussian Expansion (MGE) photometric measurements, and treating luminosity as the dependent variable, the FP has coefficients a = 1.294 ± 0.039, b = 0.912 ± 0.025, and zero-point c = 7.067 ± 0.078. We leverage the high signal-to-noise of SAMI integral field spectroscopy, to determine how structural and stellar-population observables affect the scatter about the FP. The FP residuals correlate most strongly (8σ significance) with luminosity-weighted simple-stellar-population (SSP) age. In contrast, the structural observables surface mass density, rotation-to-dispersion ratio, Sérsic index and projected shape all show little or no significant correlation. We connect the FP residuals to the empirical relation between age (or stellar mass-to-light ratio ϒ⋆ ) and surface mass density, the best predictor of SSP age amongst parameters based on FP observables. We show that the FP residuals (anti-)correlate with the residuals of the relation between surface density and ϒ⋆ . This correlation implies that part of the FP scatter is due to the broad age and ϒ⋆ distribution at any given surface mass density. Using virial mass and ϒ⋆ we construct a simulated FP and compare it to the observed FP. We find that, while the empirical relations between observed stellar population relations and FP observables are responsible for most (75 per cent) of the FP scatter, on their own they do not explain the observed tilt of the FP away from the virial plane.

Gamma-ray Bursts Cosmology with The X-ray Fundamental Plane Relation

Cosmological models and the value of their parameters are at the center of the debate because of the tension between the results obtained by the SNe Ia data and the Plank ones of the Cosmic Microwave Background Radiation. Thus, adding cosmological probes observed at high redshifts, such as Gamma-Ray Bursts (GRBs), is needed. Using GRB correlations between luminosities and a cosmological independent variable is challenging because GRB luminosities vary widely. We corrected a tight correlation between the rest-frame end time of the X-ray plateau, its corresponding X-ray luminosity, and the peak prompt luminosity: the so-called fundamental plane relation, using the jet opening angle. Its intrinsic scatter is 0:017 m 0:010 dex, 95% smaller than the isotropic fundamental plane relation, the smallest compared to any current GRB correlation in the literature. This shows that GRBs can be used as reliable cosmological tools. We use this GRB corrected correlation for the so-called platinum sample (a well-defined set with relatively flat plateaus), together with SNe Ia data, to constrain different cosmological parameters like the matter content of the universe today, M, the Hubble constant H0, and the dark energy parameter w for a wCDM model. We confirm the wCDM model but using GRBs up to z = 5, a redshift range much larger than one of SNe Ia.

Fundamental Plane of BOSS galaxies: Correlations with galaxy properties, density field and impact on RSD measurements.

Fundamental plane of elliptical galaxies can be used to predict the intrinsic size of galaxies and has a number of plausible application to study cosmology and galaxy physics. We present a detailed analysis of the fundamental plane of the SDSS-III BOSS LOWZ and CMASS galaxies. For the standard fundamental plane, we find a strong redshift evolution for the mean residual and show that it is primarily driven by the redshift evolution of the surface brightness of the galaxies. After correcting for the redshift evolution, the FP residuals are strongly correlated with the galaxy properties and some observational systematics. We show that the variations in the FP between the central and satellite galaxies, that have been observed in the literature, can primarily be explained by the correlation of the FP with the galaxy luminosity. We also measure the cross correlations of the FP residuals with the galaxy density field. The amplitude of the cross correlations depends on the galaxy properties and environment with brighter and redder galaxies showing stronger correlation. In general, galaxies in denser environments (higher galaxy bias ) show stronger correlations. We also compare FP amplitude with the amplitudes of intrinsic alignments of galaxy shapes (IA), finding the two to be correlated. Finally, using the FP residuals we also study the impact of intrinsic vhjytrds alignments on the constraint of growth rate using redshift space distortions. We do not observe any significant trends in measurements of the growth rate f as function of the amplitude of FP-density correlations, resulting in null detection of the effects of IA on the RSD measurements.