We infer the absolute time dependence of kinematic gas temperature along a proposed orbit of molecular clouds in the Central Molecular Zone (CMZ) of the Galactic Center (GC). Ammonia gas temperature maps are one of the results of the "Survey of Water and Ammonia in the Galactic Center" (SWAG, PI: J. Ott); the dynamical model of molecular clouds in the CMZ was taken from Kruijssen et al. (2015). We find that gas temperatures increase as a function of time in both regimes before and after the cloud passes pericenter on its orbit in the GC potential. This is consistent with the recent proposal that pericenter passage triggers gravitational collapse. Other investigated quantities (line width, column density, opacity) show no strong sign of time dependence but are likely dominated by cloud-to-cloud variations.
@article{arxiv.1610.01615,
title = {Temperature Evolution of Molecular Clouds in the Central Molecular Zone},
author = {Nico Krieger and Jürgen Ott and Fabian Walter and J. M. Diederik Kruijssen and Henrik Beuther and the SWAG team},
journal= {arXiv preprint arXiv:1610.01615},
year = {2017}
}
Comments
2 pages, 2 figures, to appear in Proceedings of IAU Symposium 322, The Multi-Messenger Astrophysics of the Galactic Centre, Steve Longmore, Geoff Bicknell and Roland Crocker, eds