A hydrodynamical study of outflows in starburst galaxies with different driving mechanisms

Abstract

Outflows from starburst galaxies can be driven by thermal pressure, radiation and cosmic rays. We present an analytic phenomenological model that accounts for these contributions simultaneously to investigate their effects on the hydrodynamical properties of outflows. We assess the impact of energy injection, wind opacity, magnetic field strength and the mass of the host galaxy on flow velocity, temperature, density and pressure profiles. For an M82-like wind, a thermally-dominated driving mechanism is found to deliver the fastest and hottest wind. Radiation-driven winds in typical starburst-galaxy configurations are unable to attain the higher flow velocities and temperatures associated with thermal and cosmic ray-driven systems, leading to higher wind densities which would be more susceptible to cooling and fragmentation at lower altitudes. High opacity winds are more sensitive to radiative driving, but terminal flow velocities are still lower than those achieved by other driving mechanisms at realistic opacities. We demonstrate that variations in the outflow magnetic field can influence its coupling with cosmic rays, where stronger fields enable greater streaming but less driving near the base of the flow, instead with cosmic rays redirecting their driving impact to higher altitudes. The gravitational potential is less important in M82-like wind configurations, and substantial variations in the flow profiles only emerge at high altitude in massive haloes. This model offers a more generalised approach to examine the large scale hydrodynamical properties for a wide variety of starburst galaxies.

16 pages, 9 figures, 3 tables, accepted for publication in MNRAS

References in corpus (13)

• Global cosmic-ray related luminosity and energy budget of the Milky Way
• Ionized gas outflows and global kinematics of low-z luminous star forming galaxies
• Dynamics of Dusty Radiation Pressure Driven Shells and Clouds: Fast Outflows from Galaxies, Star Clusters, Massive Stars, and AGN
• Measuring the cosmic ray acceleration efficiency of a supernova remnant
• The dependence of cosmic ray driven galactic winds on halo mass
• Lyman Alpha Driven Outflows Around Star Forming Galaxies
• Constraints on the dynamical evolution of the galaxy group M81
• Super stellar clusters with a bimodal hydrodynamic solution: an Approximate Analytic Approach
• Winds from clu\sters with non-uniform stellar distributions
• Starburst and post-starburst high-redshift protogalaxies: The feedback impact of high energy cosmic rays
• Covariant polarized radiative transfer on cosmological scales for investigating large-scale magnetic field structures
• Hadronic Interactions of Energetic Charged Particles in Protogalactic Outflow Environments and Implications for the Early Evolution of Galaxies
• Missing Halo Baryons and Galactic Outflows

Cited by in corpus (10)

• CHANG-ES XXIII: Influence of a galactic wind in NGC 5775
• The radio continuum perspective on cosmic-ray transport in external galaxies
• Characterising the signatures of star-forming galaxies in the extra-galactic $\gamma$-ray background
• The extragalactic $\gamma$-ray background: imprints from the physical properties and evolution of star-forming galaxy populations
• Outflows in the presence of cosmic rays and waves
• Outflows in the presence of cosmic rays and waves with cooling
• Dynamics of hot galactic winds launched from spherically-stratified starburst cores
• Massive Galaxies Impede Massive Outflows
• Mass-Loading and Non-Spherical Divergence in Hot Galactic Winds: Implications for X-ray Observations
• Outflows from starburst galaxies with various driving mechanisms and their X-ray properties