What can transonic wind solutions tell us about mass loading across galaxy masses?

A steady wind model connects stellar feedback, galactic gravity and observed outflow velocities.

Transonic galactic wind model including stellar Feedbacks and application to outflows in high/low-z galaxies

Transonic galactic wind model including stellar Feedbacks and application to outflows in high/low-z galaxies. Igarashi, Asuka; Mori, Masao; Nitta, Shin-ya, Publications of the Astronomical Society of Japan, 75, 1214-1245 (2023).

arXiv:2310.02780 Publication · DOI

Approach

Spherically symmetric flow equations include distributed supernova mass and energy injection and the potentials of stars and dark matter. Observed speeds constrain mass fluxes.

Main result

The inferred mass loading decreases with galaxy mass and star formation rate. Lower-mass galaxies can eject interstellar gas more efficiently in this framework.

Scientific implications

The model links wind acceleration to the removal of baryons and provides a physical interpretation of mass-loading trends.

Scope and limitations

Steady spherical solutions simplify time-dependent, multiphase winds; mass-flux estimates inherit uncertainties in both the model and measured velocities.