On the Origin of Exponential Radial Profiles in Galaxy Disks
Abstract
Exponential radial profiles are ubiquitous in galaxy disks with radial extents sometimes reaching 10 scale lengths or more. Proposed origins include stellar scattering off of bars and spirals, but unbarred, spiral-free dwarf irregular galaxies have exponential profiles too. We propose that the origin of this structure is related to stellar scattering off of interstellar structures, such as clouds and holes. We show 3D simulations and analytical derivations of this effect. The key seems to be the prevalence of random stellar scattering with an average inward bias. The scale length is derived in terms of this bias and the mean free path for scattering. Connections between the theory and observations will be discussed.
- Publication:
-
American Astronomical Society Meeting Abstracts #229
- Pub Date:
- January 2017
- Bibcode:
- 2017AAS...22911404E