%0 Generic %1 liang2018model %A Liang, Cameron J. %A Remming, Ian S. %D 2018 %K cgm cloud simulations small %T On the model of the circumgalactic mist: the implications of cloud sizes in galactic winds and halos %U http://arxiv.org/abs/1806.10688 %X Ubiquitous detections of cold/warm gas around galaxies indicate that the circumgalactic medium (CGM) is multiphase and dynamic. Recent state-of-the-art cosmological galaxy simulations have generally underproduced the column density of cold halo gas. We argue that this may be due to a mismatch of spatial resolution in the circumgalactic space and the relevant physical scales at which the cold gas operates. Using semi-analytic calculations and a set of magnetohydrodynamic (MHD) simulations, we present a multiphase model of the gaseous halos around galaxies, the circumgalactic mist (CGm). The CGm model is based on the idea that the observed cold halo gas may be a composite of cold, dense and small cloudlets embedded in a hot diffuse halo, resembling terrestrial clouds and mist. We show that the resulting cold gas from thermal instabilities conforms to a characteristic column density of $N_H\approx 10^17cm^-2$ as predicted by the $c_s t_cool$ ansatz. The model implies a large number of cold clumps in the inner galactic halo with a small volume filling factor but large covering fraction. The model also naturally gives rise to spatial extents and differential covering fractions of cold, warm and hot gas. To self-consistently model the co-evolution of the CGM and star formation within galaxies, future simulations must address the mismatch of the spatial resolution and characteristic scale of cold gas.

@misc{liang2018model, abstract = {Ubiquitous detections of cold/warm gas around galaxies indicate that the circumgalactic medium (CGM) is multiphase and dynamic. Recent state-of-the-art cosmological galaxy simulations have generally underproduced the column density of cold halo gas. We argue that this may be due to a mismatch of spatial resolution in the circumgalactic space and the relevant physical scales at which the cold gas operates. Using semi-analytic calculations and a set of magnetohydrodynamic (MHD) simulations, we present a multiphase model of the gaseous halos around galaxies, the circumgalactic mist (CGm). The CGm model is based on the idea that the observed cold halo gas may be a composite of cold, dense and small cloudlets embedded in a hot diffuse halo, resembling terrestrial clouds and mist. We show that the resulting cold gas from thermal instabilities conforms to a characteristic column density of $N_{\rm H}\approx 10^{17}\rm{cm^{-2}}$ as predicted by the $c_s t_{\rm cool}$ ansatz. The model implies a large number of cold clumps in the inner galactic halo with a small volume filling factor but large covering fraction. The model also naturally gives rise to spatial extents and differential covering fractions of cold, warm and hot gas. To self-consistently model the co-evolution of the CGM and star formation within galaxies, future simulations must address the mismatch of the spatial resolution and characteristic scale of cold gas.}, added-at = {2018-06-29T12:47:09.000+0200}, author = {Liang, Cameron J. and Remming, Ian S.}, biburl = {https://www.bibsonomy.org/bibtex/2c48eaf2d8a4531e8a84bba5e8908bfd8/miki}, description = {[1806.10688] On the model of the circumgalactic mist: the implications of cloud sizes in galactic winds and halos}, interhash = {485a61a61f97a9675c9915a8ada57cf1}, intrahash = {c48eaf2d8a4531e8a84bba5e8908bfd8}, keywords = {cgm cloud simulations small}, note = {cite arxiv:1806.10688Comment: Submitted to MNRAS, comments welcome}, timestamp = {2018-06-29T12:47:09.000+0200}, title = {On the model of the circumgalactic mist: the implications of cloud sizes in galactic winds and halos}, url = {http://arxiv.org/abs/1806.10688}, year = 2018 }