activity
20242026
collaborators

11 papers

astro-ph.GA2026

Tailored mass estimators for Milky Way dwarf Spheroidals

Sofia L. Splawska, Raphaël Errani, Jorge Peñarrubia +1

Assuming spherical symmetry and dynamical equilibrium within a given gravitational potential, a dwarf spheroidal (dSph) galaxy's globally averaged stellar velocity dispersion depen…

astro-ph.GA2026

HSTPROMO Internal Proper Motion Kinematics of Dwarf Spheroidal Galaxies: II. Velocity Anisotropy and Dark Matter Cusp Slope of Sculptor

Eduardo Vitral, Roeland P. van der Marel, Sangmo Tony Sohn +8

We analyze three epochs of HST imaging over 20 years for the Sculptor dwarf spheroidal galaxy, measuring precise proper motions for 119 stars and combining them with 1760 existing…

astro-ph.GA2026

Signatures of dark subhalos in dwarf spheroidal galaxies: I. Fluctuations in surface density

Eduardo Vitral, Jorge Peñarrubia, Matthew G. Walker

Dark matter (DM) subhalos offer critical tests of cosmological models through their abundance and properties, yet most remain undetectable due to their lack of stars. We investigat…

astro-ph.GA2025

: Tidal Disruption in Crater 2 and Formation of Diffuse Dwarf Galaxies in the Local Group

Guilherme Limberg, Alexander P. Ji, Ting S. Li +19

We present results of a spectroscopic campaign around the diffuse dwarf galaxy Crater 2 (Cra2) and its tidal tails as part of the Southern Stellar Stream Spectroscopic Survey ($S^5…

astro-ph.GA2025

Stellar Mass Segregation in Dark Matter Halos

Raphaël Errani, Jorge Peñarrubia, Matthew G. Walker

We study the effect of stellar mass segregation driven by collisional relaxation within the potential well of a smooth dark matter halo. This effect is of particular relevance for…

astro-ph.GA2025

Gravothermal expansion of dwarf spheroidal galaxies heated by dark subhaloes

Jorge Peñarrubia, Raphaël Errani, Eduardo Vitral +1

We use analytical and -body methods to study the evolution of dwarf spheroidal galaxies (dSphs) embedded in dark matter (DM) haloes that host a sizeable subhalo population. Dark…