Shell galaxies: kinematical signature of shells, satellite galaxy disruption and dynamical friction

Abstract

Stellar shells observed in many giant elliptical and lenticular as well as a few spiral and dwarf galaxies presumably result from radial minor mergers of galaxies. We show that the line-of-sight velocity distribution of the shells has a quadruple-peaked shape. We found simple analytical expressions that connect the positions of the four peaks of the line profile with the mass distribution of the galaxy, namely, the circular velocity at the given shell radius and the propagation velocity of the shell. The analytical expressions were applied to a test-particle simulation of a radial minor merger, and the potential of the simulated host galaxy was successfully recovered. Shell kinematics can thus become an independent tool to determine the content and distribution of dark matter in shell galaxies up to ~100 kpc from the center of the host galaxy. Moreover we investigate the dynamical friction and gradual disruption of the cannibalized galaxy during the shell formation in the framework of a simulation with test particles. The coupling of both effects can considerably redistribute positions and luminosities of shells. Neglecting them can lead to significant errors in attempts to date the merger in observed shell galaxies.

PhD thesis, the thesis pulls videos at: https://pc048b.fzu.cz/~ivana/shells/phd/

References in corpus (9)

• The Structure & Dynamics of Massive Early-type Galaxies: On Homology, Isothermality and Isotropy inside one Effective Radius
• Measuring the non-thermal pressure in early type galaxy atmospheres: A comparison of X-ray and optical potential profiles in M87 and NGC1399
• Investigating the Andromeda Stream: III. A Young Shell System in M31
• The shape of the dark matter halo in the early-type galaxy NGC 2974
• Was the Andromeda Stream Produced by a Disk Galaxy?
• Galaxy Mergers at z>1 in the HUDF: Evidence for a Peak in the Major Merger Rate of Massive Galaxies
• The GALEX UV emission in shell galaxies: tracing galaxy "rejuvenation" episodes
• HST/ACS observations of shell galaxies: inner shells, shell colours and dust
• XMM-Newton X-ray and Optical Monitor far UV observations of NGC 7070A and ESO 2400100 shell galaxies

Cited by in corpus (6)

• The Origin of Faint Tidal Features Around Galaxies in the RESOLVE Survey
• NGC 4993, the shell galaxy host of GW170817: constraints on the recent galactic merger
• The Impact of Merging on The Origin of Kinematically Misaligned and Counter-rotating Galaxies in MaNGA
• MOND implications for spectral line profiles of shell galaxies: shell formation history and mass-velocity scaling relations
• The nature of the Eastern Extent in the outer halo of M31
• Origin of the spectacular tidal shells of galaxy NGC474