Is Wind-AE the right tool for me?

Wind-AE is well-suited for users interested in quickly estimating mass loss rates or outflow structure. Outflow structure includes bulk temperature and per-species ionization fractions as a function of radius, so can be easily translated into approximating and predicting observables and transits, including metastable helium (He 10830:math:AA) transits, though a He transit module is not yet included. Precise modeling of lower atmosphere (\(\lesssim 100\) microbar) is considered necessary for highly accurate transit models, but Wind-AE can be easily coupled to lower atmosphere photochemistry models whose outputs (e.g., radius, temperature, abundances, ionization fractions, etc. at 1 microbar) can be fed into Wind-AE as inputs.

Note

If you are interested in outflow structure: Past the Coriolis turning radius (a few planetary radii) 3D physics dominates, so Wind-AE does not integrate past that point. Wind-AE also makes simplifying assumptions about the region below the wind-launch radius (~10 nanobars).

Because Wind-AE runs on the order of seconds to minutes, it can be (and has been) used to model planet evolution.

Wind-AE can model:

  • Multiple atomic species

  • X-ray physics (secondary ionizations and K-shell ionization cross-sections for relevant metals)

  • Both low and high stellar XUV flux

  • Heating & Cooling: Ionization heating, bolometric heating & cooling (negligible in wind), PdV cooling (work done due to expansion of gas), radiative / atomic line cooling (Lyman-alpha, OI, OII, OIII, CI, CII), recombination cooling

Wind-AE does not (currently) include:

  • Magnetic fields

  • Time dependence

  • Diffusion/drag - the atomic species set by the user are assumed to be entrained in the outflow and in thermal equilibrium. This is an appropriate assumption for species below the crossover mass and a warning will be raised.

  • Heating & Cooling:

    • Conduction (warning raised if relevant, planned)

    • H3+ line cooling (not planned)

    • Fe & Ca line cooling (relevant at high Z only, planned)

    • Free-free cooling (warning raised if relevant, not planned)

  • Multiple ionization states of the same species (planned)

See Broome et al. (submitted) for more details.

Other tools and models:

  • Want a rapid H/He model with power-law approximated XUV spectra? Check out ATES (Caldiroli et al. 2021)

  • Do you want to set the mass loss rate (\(\dot{M}\)) yourself or want an EUV isothermal Parker wind outflow model that runs in nanoseconds? Check out p-winds (Dos Santos et al. 2022)

  • Do you want to use p-winds and get transit models for metals via Cloudy? Check out Sunbather (Linssen et al. 2024)

  • Want to leverage Cloudy and the hydrodynamic code PLUTO for more thorough XUV-irradiated, but slightly more expensive calculations? Check out TPCI (Salz et al. 2015)

  • That sound great, but you prefer to code in Python over C/C++? Check out pyTPCI (Riley, Zhang, & Bean 2025 <https://ui.adsabs.harvard.edu/abs/2025ApJ…980…34R/abstract>)

  • Do you care about diffusion throughout the wind? Check out AIOLIS (Schulik & Booth, 2022 <https://ui.adsabs.harvard.edu/abs/2023MNRAS.523..286S/abstract>)

  • Want to model the lower atmosphere in more detail? Check out CETIMB (Koskinen et al. 2022)

  • Just want a grid of mass loss rates for pure-Hydrogen, low-flux-EUV-irradiated planets? See Kubyshkina & Fossati

  • Want a grid of mass loss rates for pure-Hydrogen, high-flux-XUV-irradiated planets? See Owen & Jackson (2012)

Note

Want your model added to this list or to update the short bio? Email mabroome@ucsc.edu