NIHAO XV: the environmental impact of the host galaxy on galactic satellite and field dwarf galaxies

• DOI: 10.1093/mnras/sty2913
• Publication Date: 2018-10-26T19:44:55Z
• Authors: Tobias Buck; Andrea V Macciò; Aaron A Dutton; Aura Obreja; Jonas Frings
• Keywords: Satellite galaxy; Dwarf galaxy problem; Dwarf spheroidal galaxy

We study the impact of host on dwarf galaxy properties using four new Milky Way-like, ultra high-resolution simulations, ($N_{\rm part} >10^7$) from NIHAO project. split our sample in satellite ($R<R_{200}$), nearby ($1<R/R_{200}<2.5$), and field ($R>2.5 R_{\rm 200}$) galaxies. Simulated galaxies all three groups are excellent agreement with Local Group terms of: stellar mass-velocity dispersion, mass-metallicity relation, star formation histories, mass functions. Satellites show lower velocity dispersions gas fractions compared to While follow global abundance matching relations, satellites deviate them, showing dark matter masses for given mass. The reason this deficit is substantial loss experienced by $\sim80$\% galaxies, while orbiting inside $R_{200}$ at earlier times. However, both objects fall back onto relation if we use maximum their virial instead present-day value. This allows us provide estimates peak observed Finally, radial velocities, distances, dispersion-stellar derive a metric distinguish between harassed central object unaffected ones. Applying find that even far away like Eri II ($D\approx$ 370 kpc) have strong probability ($\approx 83$\%) having been affected Way past. naturally explains lack recent seen II.