The global mass - to - light ratio of SLACS lenses

Abstract

The dark matter content of early,- type galaxies (ETGs) is a hotly debated topic with contrasting results arguing in favour or against the presence of significant dark mass within the effective radius and the change with luminosity and mass. In order to address this question, we investigate here the global mass - to - light ratio ${\rm Y}(r)=M(r)/L(r)$ of a sample of 21 lenses observed within the Sloan Lens ACS (SLACS) survey. We follow the usual approach of modeling the galaxy as a two component systems, but we use a phenomenological ansatz for ${\rm Y}(r)$, proposed by some of us in Tortora et al. (2007), able to smoothly interpolate between constant $M/L$ models and a wide class of dark matter haloes. The resulting galaxy model is then fitted to the data on the Einstein radius and velocity dispersion. Our phenomenological model turns out to be in well agreement with the data suggesting the presence of massive dark matter haloes in order to explain the lensing and dynamics properties of the SLACS lenses. According to the values of the dark matter mass fraction, we argue that the halo may play a significant role in the inner regions probed by the data, but such a conclusion strongly depends on the adopted initial mass function of the stellar population. Finally, we find that the dark matter mass fraction within $R_{eff}$ scales with both the total luminosity and stellar mass in such a way that more luminous (and hence more massive) galaxies have a larger dark matter content.

22 pages, 3 figures, 5 tables, revised version (typos corrected) accepted for publication on Astronomy and Astrophysics

References in corpus (6)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Likelihoods and Parameters from the WMAP data
• The Sloan Lens ACS Survey. III - The Structure and Formation of Early-type Galaxies and their Evolution since z~1
• The Sloan Lens ACS Survey. IV: the mass density profile of early-type galaxies out to 100 effective radii
• Towards a Concordant Model of Halo Occupation Statistics
• Is AGN feedback necessary to form red elliptical galaxies?
• The UV properties of E+A galaxies: constraints on feedback-driven quenching of star formation

Cited by in corpus (23)

• The Sloan Lens ACS Survey. X. Stellar, Dynamical, and Total Mass Correlations of Massive Early-type Galaxies
• Finding Strong Gravitational Lenses in the Kilo Degree Survey with Convolutional Neural Networks
• The SL2S Galaxy-scale Lens Sample. II. Cosmic evolution of dark and luminous mass in early-type galaxies
• Lens galaxies in the Illustris simulation: power-law models and the bias of the Hubble constant from time-delays
• Elliptical galaxy masses out to five effective radii: the realm of dark matter
• Central dark matter trends in early-type galaxies from strong lensing, dynamics and stellar populations
• The SWELLS survey. III. Disfavouring "heavy" initial mass functions for spiral lens galaxies
• Systematic variations of central mass density slopes in early-type galaxies
• Spherical galaxy models as equilibrium configurations in nonextensive statistics
• The MOND Fundamental Plane
• SPIDER - VI. The Central Dark Matter Content of Luminous Early-Type Galaxies: Benchmark Correlations with Mass, Structural Parameters and Environment
• Secondary infall model and dark matter scaling relations in intermediate redshift early - type galaxies
• Dark matter scaling relations in intermediate z haloes
• Evolution of central dark matter of early-type galaxies up to z ~ 0.8
• The last 6 Gyr of dark matter assembly in massive galaxies from the Kilo Degree Survey
• Gravitational lensing by wave dark matter halos
• A relation between the dark mass of elliptical galaxies and their shape
• Central velocity dispersion catalog of LAMOST-DR7 galaxies
• The central dark matter fraction of massive early-type galaxies
• The quantity of dark matter in early-type galaxies and its relation to the environment
• New Analysis of Dark Matter in Elliptical Galaxies
• Cosmological parameters from lenses distance ratio
• Dark matter and alternative recipes for the missing mass