Evolution of M82-like starburst winds revisited: 3D radiative cooling hydrodynamical simulations

Abstract

In this study we present three-dimensional radiative cooling hydrodynamical simulations of galactic winds generated particularly in M82-like starburst galaxies. We have considered intermittent winds induced by SNe explosions within super star clusters randomly distributed (in space and time) in the central region of the galaxy (within a radius R = 150 pc) and were able to reproduce the observed M82 wind conditions with its complex morphological outflow structure. We have found that the environmental conditions in the disk in nearly recent past are crucial to determine whether the wind will develop a large scale rich filamentary structure, as in M82 wind, or not. If a sufficiently large number of super stellar clusters is build up in a starburst mainly over a period of a few million years, then the simulations reproduce the multi-phase gas observed in M82-like winds, i.e., with filaments of sizes about 20 to 300 pc, velocities of ∼ 200 -500 km/s, densities in the range of 10 −1 -10 cm −3 , embedded in a hot low density gas with a density smaller than 10 −2 cm −3 and a velocity of ∼ 2000 km s −1 . Otherwise, a "superbubble-like" wind develops, with very poor or no cold filamentary structures. Also, the numerical evolution of the SN ejecta have allowed us to obtain the abundance distribution over the first ∼ 3 kpc extension of the wind and we have found that the SNe explosions change significantly the metallicity only of the hot, low-density wind component for which we obtained abundances ∼ 5 to 10 Z ⊙ in fair consistency with the observations. Moreover, we have found that the SN-driven wind transports to outside the disk large amounts of energy, momentum and gas, but the more massive high-density component reaches only intermediate altitudes smaller than 1.5 kpc. Therefore, no significant amounts of gas mass are lost to the IGM and the mass evolution of the galaxy is not much affected by the starburst events occurring in the nuclear region.

Charge-exchange emission and cold clumps in multiphase galactic outflows

“…the model of bubble buoyancy in Cen A, Saxton et al 2001), while others may be heated and evaporated as they traverse up the outflow zone. Galactic outflows are evidently complex, multi-component, multi-phase fluids (see Ohyama et al 2002;Strickland et al 2002;Melioli et al 2013;Martín-Fernández et al 2016), where hot ionised gases, warm partially ionised gases and cool neutral material intermingle as well as segregate.…”

Filament formation in wind–cloud interactions– II. Clouds with turbulent density, velocity, and magnetic fields

“…Investigating the dynamics and longevity of wind-swept interstellar clouds is essential to understanding stellar-and supernova-driven, multi-phase winds and outflows, as well as the formation and evolution of filaments embedded in them. Wind-swept clouds and filaments have been observed and studied at various scales in the interstellar medium (ISM), such as in the shells of supernova remnants (e.g., see Hester et al 1996;Koo et al 2007;Shinn et al 2009;Patnaude & Fesen 2009;McEntaffer et al 2013;Nynka et al 2015 for observations;and Stone & Norman 1992;Melioli, de Gouveia dal Pino & Raga 2005;Melioli et al 2006;Orlando et al Tully 1988;Shopbell & Bland-Hawthorn 1998;Cecil, Bland-Hawthorn & Veilleux 2002;Crawford et al 2005;Matsubayashi et al 2009;McClure-Griffiths et al 2012Tombesi et al 2015;Veilleux et al 2017 for observations;and Strickland & Stevens 2000;Melioli et al 2008Melioli et al , 2009Cooper et al 2008Cooper et al , 2009Melioli, de Gouveia Dal Pino & Geraissate 2013;Scannapieco 2017 for models), and also in ram-pressure-stripped galaxies (e.g., see Abramson & Kenney 2014;Kenney, Abramson & Bravo-Alfaro 2015 for observations;and Marcolini, Brighenti & D'Ercole 2003;Kronberger et al 2008;Pfrommer & Dursi 2010;Vijayaraghavan & Ricker 2015 for models).…”

Comment on “Calorimetric Dark Matter Detection with Galactic Center Gas Clouds”

“…The HVNO clouds are in the hot, high-velocity wind (10 6−7 K, 330 km/s) emanating from the Galactic Center. This extreme environment causes shocks and other destructive effects, likely making the clouds transient objects [3][4][5][6][7][8][9][10]. However deriving DM bounds based on heat transport requires the system to be in a steady state at the current temperature over the long timescales associated with its purported radiative cooling rate, invalidating the use of a system for which the required stability is doubtful.…”