The Stellar Mass Fundamental Plane: The virial relation and a very thin plane for slow-rotators

Abstract

Early-type galaxies -- slow and fast rotating ellipticals (E-SRs and E-FRs) and S0s/lenticulars -- define a Fundamental Plane (FP) in the space of half-light radius $R_e$, enclosed surface brightness $I_e$ and velocity dispersion ${\sigma }_e$. Since $I_e$ and ${\sigma }_e$ are distance-independent measurements, the thickness of the FP is often expressed in terms of the accuracy with which $I_e$ and ${\sigma }_e$ can be used to estimate sizes $R_e$. We show that: 1) The thickness of the FP depends strongly on morphology. If the sample only includes E-SRs, then the observed scatter in $R_e$ is $\sim 16\%$, of which only $\sim 9\%$ is intrinsic. Removing galaxies with $M_{\ast }<10^{11}{M}_{\odot }$ further reduces the observed scatter to $\sim 13\%$ ($\sim 4\%$ intrinsic). The observed scatter increases to the $\sim 25\%$ usually quoted in the literature if E-FRs and S0s are added. If the FP is defined using the eigenvectors of the covariance matrix of the observables, then the E-SRs again define an exceptionally thin FP, with intrinsic scatter of only $5\%$ orthogonal to the plane. 2) The structure within the FP is most easily understood as arising from the fact that $I_e$ and ${\sigma }_e$ are nearly independent, whereas the $R_e-I_e$ and $R_e-{\sigma }_e$ correlations are nearly equal and opposite. 3) If the coefficients of the FP differ from those associated with the virial theorem the plane is said to be `tilted'. If we multiply $I_e$ by the global stellar mass-to-light ratio $M_{\ast }/L$ and we account for non-homology across the population by using Sérsic photometry, then the resulting stellar mass FP is less tilted. Accounting self-consistently for $M_{\ast }/L$ gradients will change the tilt. The tilt we currently see suggests that the efficiency of turning baryons into stars increases and/or the dark matter fraction decreases as stellar surface brightness increases.

13 pages, 9 figures, 3 tables, accepted for publication in MNRAS

References in corpus (10)

• The 2.5 m Telescope of the Sloan Digital Sky Survey
• Overview of the SDSS-IV MaNGA Survey: Mapping Nearby Galaxies at Apache Point Observatory
• The SAURON project -- IX. A kinematic classification for early-type galaxies
• The MaNGA Integral Field Unit Fiber Feed System for the Sloan 2.5 m Telescope
• The SDSS-IV MaNGA Sample: Design, Optimization, and Usage Considerations
• A catalogue of 2D photometric decompositions in the SDSS-DR7 spectroscopic main galaxy sample: preferred models and systematics
• SDSS-IV MaNGA: Spatially resolved star formation histories in galaxies as a function of galaxy mass and type
• The 6dF Galaxy Survey: Peculiar Velocity Field and Cosmography
• Comparing PyMorph and SDSS photometry. I. Background sky and model fitting effects
• Stellar mass functions and implications for a variable IMF

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• The SLACS strong lens sample, debiased
• A common origin for the Fundamental Plane of quiescent and star-forming galaxies in the EAGLE simulations
• Stellar population analysis of MaNGA early-type galaxies: IMF dependence and systematic effects
• The Fundamental Plane Is Not a Plane: Warped Nature of the Fundamental Plane of Early-type Galaxies and Its Implication for Galaxy Formation
• The hyperplane of early-type galaxies: using stellar population properties to increase the precision and accuracy of the fundamental plane as a distance indicator
• The catalogue of virtual early-type galaxies from IllustrisTNG: validation and real observation consistency
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• TDCOSMO XXI. Accurate stellar velocity dispersions of the SL2S lens sample and the fundamental plane of the lensing mass