Systematic trends in total mass profiles from dynamical models of early-type galaxies

Adriano Poci*, Michele Cappellari, Richard M. McDermid

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)


We study trends in the slope of the total mass profiles and dark matter fractions within the central half-light radius of 258 early-type galaxies, using data from the volume-limited ATLAS3D survey.We use three distinct sets of dynamical models, which vary in their assumptions and also allow for spatial variations in the stellarmass-to-light ratio, to test the robustness of our results. We confirm that the slopes of the total mass profiles are approximately isothermal, and investigate how the total mass slope depends on various galactic properties. The most statistically significant correlations we find are a function of either surface density, Σe, or velocity dispersion, σe. However there is evidence for a break in the latter relation, with a nearly universal logarithmic slope above log10e/(km s-1)] ~ 2.1 and a steeper trend below this value. For the 142 galaxies above that critical σe value, the total mass-density logarithmic slopes have a mean value 〈γ'〉 = -2.193 ± 0.016 (1σ error) with an observed rms scatter of only σγ' = 0.168 ± 0.015. Considering the observational errors, we estimate an intrinsic scatter of σγ' intr ≈ 0.15. These values are broadly consistent with those found by strong lensing studies at similar radii and agree, within the tight errors, with values recently found at much larger radii via stellar dynamics or H I rotation curves (using significantly smaller samples than this work).

Original languageEnglish
Pages (from-to)1397-1413
Number of pages17
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
Publication statusPublished - 2017


  • galaxies: elliptical and lenticular, cD
  • galaxies: kinematics and dynamics
  • galaxies: stellar content
  • galaxies: structure
  • dark matter


Dive into the research topics of 'Systematic trends in total mass profiles from dynamical models of early-type galaxies'. Together they form a unique fingerprint.

Cite this