Effects of mass models on dynamical mass estimate: the case of ultra diffuse galaxy NGC1052-DF2

Abstract

NGC1052-DF2 was recently discovered as the dark-matter deficient galaxy claimed by van Dokkum et al. (2018a, vD18). However, large uncertainties on its dynamical mass estimate have been pointed out, concerning the paucity of sample, statistical methods and distance measurements. In this work, we discuss the effects of the difference in modeling of the tracer profile of this galaxy on the dynamical mass estimate. To do this, we assume that the tracer densities are modeled with power-law and Sérsic profiles, and then we solve the spherical Jeans equation to estimate the dynamical mass. Applying these models to kinematic data of globular clusters in NGC1052-DF2, we compare 90 per cent upper limits of dynamical mass-to-light ratios estimated between from this analysis and from vD18. We find that the upper limit obtained by the power-law is virtually the same as the result from vD18, whilst this limit estimated by the Sérsic is significantly greater than that from vD18, thereby suggesting that NGC1052-DF2 can still be a dark-matter dominated system. Consequently, we propose that dynamical mass estimate of a galaxy is largely affected by not only small kinematic sample but the choice of tracer distributions, and thus the estimated mass still remains quite uncertain.

5 pages, 3 figures and 2 tables, Accepted for publication in MNRAS Letters

References in corpus (13)

• Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster
• A galaxy lacking dark matter
• NIHAO XI: Formation of Ultra-Diffuse Galaxies by outflows
• A High Stellar Velocity Dispersion and ~100 Globular Clusters for the Ultra Diffuse Galaxy Dragonfly 44
• A distance of 13 Mpc resolves the claimed anomalies of the galaxy lacking dark matter
• The abundance of ultra-diffuse galaxies from groups to clusters: UDGs are relatively more common in more massive haloes
• Systematics in virial mass estimators for pressure-supported systems
• Tidal stripping as a possible origin of the ultra diffuse galaxy lacking dark matter
• An enigmatic population of luminous globular clusters in a galaxy lacking dark matter
• The nearest ultra diffuse galaxy: UGC2162
• Cores and Cusps in the Dwarf Spheroidals
• Current velocity data on dwarf galaxy NGC1052-DF2 do not constrain it to lack dark matter
• Reconciling mass-estimates of ultra-diffuse galaxies

Cited by in corpus (18)

• A second galaxy missing dark matter in the NGC1052 group
• A distance of 13 Mpc resolves the claimed anomalies of the galaxy lacking dark matter
• The ultra-diffuse galaxy NGC 1052-DF2 with MUSE: I. Kinematics of the stellar body
• A spectroscopic study of MATLAS-2019 with MUSE: an ultra-diffuse galaxy with an excess of old globular clusters
• Self-Interacting Dark Matter and the Origin of Ultra-Diffuse Galaxies NGC1052-DF2 and -DF4
• Globular clusters as tracers of the dark matter content of dwarfs in galaxy clusters
• On the Orbital Decay of Globular Clusters in NGC1052-DF2: Testing a Baryon-Only Mass Model
• Probing the radial acceleration relation and the strong equivalence principle with the Coma cluster ultra-diffuse galaxies
• The Globular Cluster Population of NGC 1052-DF2: Evidence for Rotation
• A Dearth of Atomic Hydrogen in NGC1052-DF2
• Towards a higher mass for NGC1052-DF2: an analysis based on full distribution functions
• On the Evolution of the Globular Cluster System in NGC 1052-DF2: Dynamical Friction, Globular-Globular Interactions and Galactic Tides
• Evolution of subhalo orbits in a smoothly-growing host halo potential
• Frequency of the dark matter subhalo collisions and bifurcation sequence arising formation of dwarf galaxies
• Challenges in modeling the dark matter halo of NGC 1052-DF2: Cored versus cuspy halo models
• Refracting into Ultra Diffuse Galaxy NGC 1052-DF2 by Passing near the Center of NGC 1052
• On the Tidal Formation of Dark Matter Deficient Galaxies
• DHOST gravity in Ultra-diffuse galaxies -- Part I: the case of NGC1052-DF2