Ionized absorbers as evidence for supernova-driven cooling of the lower Galactic corona
Abstract
We show that the ultraviolet absorption features, newly discovered in HST spectra, are consistent with being formed in a layer that extends a few kpc above the disk of the Milky Way. In this interface between the disk and the Galactic corona, high-metallicity gas ejected from the disk by supernova feedback can mix efficiently with the virial-temperature coronal material. The mixing process triggers the cooling of the lower corona down to temperatures encompassing the characteristic range of the observed absorption features, producing a net supernova-driven gas accretion onto the disk at a rate of a few Msun/yr. We speculate that this mechanism explains how the hot-mode of cosmological accretion feeds star formation in galactic disks.
Cite
@article{arxiv.1301.4998,
title = {Ionized absorbers as evidence for supernova-driven cooling of the lower Galactic corona},
author = {Filippo Fraternali and Antonino Marasco and Federico Marinacci and James Binney},
journal= {arXiv preprint arXiv:1301.4998},
year = {2015}
}
Comments
15 pages, 4 figures, accepted for publication in ApJ Letters