The SLUGGS Survey: Multi-population dynamical modelling of the elliptical galaxy NGC 1407 from stars and globular clusters

Abstract

We perform in-depth dynamical modelling of the luminous and dark matter (DM) content of the elliptical galaxy NGC 1407. Our strategy consists of solving the spherical Jeans equations for three independent dynamical tracers: stars, blue GCs and red GCs in a self-consistent manner. We adopt a maximum-likelihood Markov-Chain Monte Carlo fitting technique in the attempt to constrain the inner slope of the DM density profile (the cusp/core problem), and the stellar initial mass function (IMF) of the galaxy. We find the inner logarithmic slope of the DM density profiles to be $\gamma =0.6\pm 0.4$, which is consistent with either a DM cusp ($\gamma =1$) or with a DM core $(\gamma =0)$. Our findings are consistent with a Salpeter IMF, and marginally consistent with a Kroupa IMF. We infer tangential orbits for the blue GCs, and radial anisotropy for red GCs and stars. The modelling results are consistent with the virial mass--concentration relation predicted by $\Lambda$CDM simulations. The virial mass of NGC 1407 is $\log$ $M_{\mathrm{vir}}=13.3\pm 0.2M_{\odot }$, whereas the stellar mass is $\log M_{\ast }=11.8\pm 0.1M_{\odot }$. The overall uncertainties on the mass of NGC 1407 are only 5 per cent at the projected stellar effective radius. We attribute the disagreement between our results and previous X-ray results to the gas not being in hydrostatic equilibrium in the central regions of the galaxy. The halo of NGC 1407 is found be DM dominated, with a dynamical mass-to-light ratio of $M/L=260_{-100}^{+174}{M}_{\odot }/L_{\odot ,B}$. However, this value can be larger up to a factor of 3 depending on the assumed prior on the DM scale radius.

15 pages, 10 figures, accepted for publication to MNRAS

References in corpus (20)

• A systematic variation of the stellar initial mass function in early-type galaxies
• The kinematic status and mass content of the Sculptor dwarf spheroidal galaxy
• On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution
• Galaxies as simple dynamical systems: observational data disfavor dark matter and stochastic star formation
• The SAGES Legacy Unifying Globulars and GalaxieS Survey (SLUGGS): Sample definition, methods, and initial results
• Kinematics of the stellar halo and the mass distribution of the Milky Way using BHB stars
• Probing the Dark Matter and Gas Fraction in Relaxed Galaxy Groups with X-ray observations from Chandra and XMM
• The PN.S Elliptical Galaxy Survey: the dark matter in NGC 4494
• Dwarf Galaxy Dark Matter Density Profiles Inferred from Stellar and Gas Kinematics
• Dark matter content and internal dynamics of NGC 4697: NMAGIC particle models from slit data and planetary nebulae velocities
• The Next Generation Virgo Cluster Survey. VI. The Kinematics of Ultra-compact Dwarfs and Globular Clusters in M87
• Eridanus - A Supergroup in the Local Universe?
• Systematic variations of central mass density slopes in early-type galaxies
• Dwarf galaxies in the Dynamically Evolved NGC 1407 Group
• The early-type galaxies NGC 1407 and NGC 1400 - I: spatially resolved radial kinematics and surface photometry
• Joint XMM-Newton and Chandra Observations of the NGC 1407/1400 Complex: a Tail of an Early-Type Galaxy and a Tale of a Nearby Merging Group
• Probing the Mass Distributions in NGC 1407 and Its Associated Group with the X-ray Imaging Spectroscopic and Optical Photometric and Line-strength Indices Data
• The Effect of Substructure on Mass Estimates of Galaxies
• Dark Matter Deprivation in Field Elliptical Galaxy NGC 7507
• Hollow cores in Warm Dark Matter halos from the Vlasov-Poisson equation

Cited by in corpus (9)

• The MASSIVE Survey - VIII. Stellar Velocity Dispersion Profiles and Environmental Dependence of Early-Type Galaxies
• The SLUGGS Survey: stellar masses and effective radii of early-type galaxies from Spitzer Space Telescope 3.6$\mu$m imaging
• A discrete chemo-dynamical model of the giant elliptical galaxy NGC 5846: dark matter fraction, internal rotation and velocity anisotropy out to six effective radii
• Dark matter concentrations in galactic nuclei according to polytropic models
• Tracing the Assembly History of NGC 1395 through its Globular Cluster System
• A discrete chemo-dynamical model of M87's globular clusters: Kinematics extending to ~ 400 kpc
• Spatially-resolved stellar populations and kinematics with KCWI: probing the assembly history of the massive early-type galaxy NGC 1407
• Total mass slopes and enclosed mass constrained by globular cluster system dynamics
• Refracted Gravity Solutions from Small to Large Scales