Dark matter scaling relations in intermediate z haloes

Abstract

We investigate scaling relations between the dark matter (DM) halo model parameters for a sample of intermediate redshift early - type galaxies (ETGs) resorting to a combined analysis of Einstein radii and aperture velocity dispersions. Modeling the dark halo with a Navarro - Frenk - White profile and assuming a Salpeter initial mass function (IMF) to estimate stellar masses, we find that the column density ${\cal{S}}$ and the Newtonian acceleration within the halo characteristic radius $r_s$ and effective radius $R_{eff}$ are not universal quantities, but correlate with the luminosity $L_V$, the stellar mass $M_{\star}$ and the halo mass $M_{200}$, contrary to recent claims in the literature. We finally discuss a tight correlation among the DM mass $M_{DM}(R_{eff})$ within the effective radius $R_{eff}$, the stellar mass $M_{\star}(R_{eff})$ and $R_{eff}$ itself. The slopes of the scaling relations discussed here strongly depend, however, on the DM halo model and the IMF adopted so that these ingredients have to be better constrained in order to draw definitive conclusions on the DM scaling relations for ETGs.Comment: 8 pages, 1 figure, 4 tables, MNRAS submitted version (including corrections after the referee report

On the surface density of dark matter haloes

“…Del found a correlation of the surface density with M200, in agreement with Napolitano et al (2010), Cardone & Tortora (2010), and Boyarsky et al (2009), but with a smaller scatter, and they also found a correlation between baryon column density and mass.…”

“…Cardone & Tortora (2010), based on central velocity dispersion of local galaxies and strong lensing at intermediate redshift, have shown that the Newtonian acceleration and column density correlate with different quantities: the visual luminosity LV , the effective radius re, the stellar mass M * and the halo mass M200 in agreement with Boyarsky et al (2009) and in disagreement with the results of D09 and G09. Napolitano et al (2010) calculated < ρDM > re, which is proportional to the column density S, for a large sample of elliptical galaxies.…”

Secondary infall model and dark matter scaling relations in intermediate-redshift early-type galaxies

“…gravitational lensing (see, e.g. Cardone & Tortora 2010; Treu et al 2010) and studies of the central DM fraction in local ETGs (Napolitano et al 2011) suggest that observations are consistent more with a Salpeter rather than a Chabrier IMF for ETGs (unless some strong AC is considered). Moreover, it has also been suggested that the IMF might vary with luminosity (Renzini & Ciotti 1993; Tortora et al 2009) with a Salpeter one being generally preferred for brighter systems (as probed by the SLACS lenses).…”

The last 6 Gyr of dark matter assembly in massive galaxies from the Kilo Degree Survey

“…The claimed correlation with mass seems almost insensitive to the adopted galaxy mass profile or initial mass function, IMF (e.g., Cardone et al 2009;Cardone & Tortora 2010;Cardone et al 2011), but it can become uncertain in case a non-ΛCDM scenario, with mass following the (non-homologous) light distribution, is adopted (e.g., Trujillo et al 2004;Tortora et al 2009Tortora et al , 2012. The scenario is even more complicated if one takes into account the effect of a non universal IMF (van Dokkum & Conroy 2010;Treu et al 2010;Thomas et al 2011;Conroy & van Dokkum 2012;Cappellari et al 2012Cappellari et al , 2013Spiniello et al 2012;Wegner et al 2012;Barnabè et al 2013;Dutton et al 2013;Ferreras et al 2013;Goudfrooij & Kruijssen 2013;La Barbera et al 2013;Tortora et al 2013;Weidner et al 2013;Goudfrooij & Kruijssen 2014;Shu et al 2015;McDermid et al 2014;Tortora et al 2014a,c;Martín-Navarro et al 2015;Spiniello et al 2015;Lyubenova et al 2016;Tortora et al 2016;Corsini et al 2017;Li et al 2017;Sonnenfeld et al 2017;Tortora et al 2017).…”