%0 Generic %1 bordoloi2016formation %A Bordoloi, Rongmon %A Heckman, Timothy M. %A Norman, Colin A. %D 2016 %K cooling gas high ionisation %T The formation and physical origin of highly ionized cooling gas %U http://arxiv.org/abs/1605.07187 %X We present a physically clear cooling flow theory that explains the origin of warm diffuse gas seen primarily as highly ionized absorption line systems in the spectra of background sources. We predict the observed column densities of several highly ionized transitions such as O VI, O VII, Ne VIII, N V, and Mg X; and present a unified comparison of the model predictions with absorption lines seen in the Milky Way disk, Milky Way halo, starburst galaxies, the circumgalactic medium and the intergalactic medium at low and high redshifts. We show that diffuse gas seen in such diverse environments can be simultaneously explained by a simple model of radiatively cooling gas. We show that most of such absorption line systems are consistent with being collisionally ionized, and estimate the maximum likelihood temperature of the gas in each observation. This model satisfactorily explains why O VI is regularly observed around star-forming low-z L* galaxies, and why N V is rarely seen around the same galaxies. We predict that the typical O VI column densities seen around these galaxies would be an order of magnitude higher than the associated N V column densities. We further present some consequences of this model in quantifying the dynamics of the cooling gas around galaxies and predict the shock velocities associated with such flows. Useful formulae for both observers and simulators are presented.

@misc{bordoloi2016formation, abstract = {We present a physically clear cooling flow theory that explains the origin of warm diffuse gas seen primarily as highly ionized absorption line systems in the spectra of background sources. We predict the observed column densities of several highly ionized transitions such as O VI, O VII, Ne VIII, N V, and Mg X; and present a unified comparison of the model predictions with absorption lines seen in the Milky Way disk, Milky Way halo, starburst galaxies, the circumgalactic medium and the intergalactic medium at low and high redshifts. We show that diffuse gas seen in such diverse environments can be simultaneously explained by a simple model of radiatively cooling gas. We show that most of such absorption line systems are consistent with being collisionally ionized, and estimate the maximum likelihood temperature of the gas in each observation. This model satisfactorily explains why O VI is regularly observed around star-forming low-z L* galaxies, and why N V is rarely seen around the same galaxies. We predict that the typical O VI column densities seen around these galaxies would be an order of magnitude higher than the associated N V column densities. We further present some consequences of this model in quantifying the dynamics of the cooling gas around galaxies and predict the shock velocities associated with such flows. Useful formulae for both observers and simulators are presented.}, added-at = {2016-05-25T12:27:21.000+0200}, author = {Bordoloi, Rongmon and Heckman, Timothy M. and Norman, Colin A.}, biburl = {https://www.bibsonomy.org/bibtex/23713ac37641ebb8535409d65189bba87/miki}, description = {[1605.07187] The formation and physical origin of highly ionized cooling gas}, interhash = {663631e0f6068b90b84cb863b9c361ca}, intrahash = {3713ac37641ebb8535409d65189bba87}, keywords = {cooling gas high ionisation}, note = {cite arxiv:1605.07187Comment: 13 pages, 9 figures, submitted to ApJ, Comments welcome}, timestamp = {2016-05-25T12:27:21.000+0200}, title = {The formation and physical origin of highly ionized cooling gas}, url = {http://arxiv.org/abs/1605.07187}, year = 2016 }