Control Parameters

Output to screen

verbose

Print lots of output to screen regarding status of calculation?

Default: True

progress_bar

Use python progress-bar (if installed)?

Default: True

Starting and stopping calculations

initial_redshift

Initial redshift of calculation, i.e., the redshift at which we switch from cosmological initial conditions to the ARES solver.

Default: 60

final_redshift

Calculation stops at this redshift.

Default: 5

track_extrema

Track 21-cm extrema in real-time. These are referred to as turning points B (first stars), C (first black holes), and D (beginning of Epoch of Reionization) in works such as Burns et al. (2012), Harker et al. (2012), and Mirocha et al. (2013).

Default: False

stop

If track_extrema==True, set stop to 'B', 'C', or 'D' to terminate the calculation once the given turning point is reached.

Default: None

stop_xavg

You can also stop a calculation once a given mean ionized fraction is reached. For instance, if you’d like to terminate once the IGM is half ionized, set stop_xavg=0.5.

Default: 0.99999

Time-stepping and data storage

time_units

Internal units for time.

Default: \(3.15576 \times 10^{13} \ \text{s}\) (i.e., 1 Myr)

initial_timestep

Time-step at initial_redshift.

Default: 0.01 [time_units]

max_dt

Maximum allowed time-step.

Default: 1 [time_units]

max_dz

Maximum allowed redshift-step.

Default: None

dtDataDump

Save all physical quantities at this time cadence.

Default: 1 [time_units]

dzDataDump

Save all physical quantities at this redshift cadence.

Default: None

epsilon_dt

Maximum fractional change in quantities of interest in a single time-step. Quantities of interest are listed in restricted_timestep (see below).

Default: 0.01

restricted_timestep

A list containing quantities use to restrict the time-step via epsilon_dt. Options:

  • 'ions': restrict time-step based on rate of change in ion fractions.

  • 'neutrals': restrict time-step based on rate of change in neutral fractions.

  • 'electrons': restrict time-step based on rate of change in electron density.

  • 'temperature': restrict time-step based on rate of change in temperature.

  • 'hubble': restrict time-step based on Hubble expansion.

Default: ['ions', 'electrons', 'temperature']

Lookup tables

tau_redshift_bins

Number of points to use when discretizing the IGM optical depth in redshift.

Default: None

tau_prefix

Path to directory on disk where optical depth tables are stored. Set this if you keep optical depth tables stored in a place other than the $ARES environment variable!

Default: None

load_sed

Same as tau_prefix, but refers to lookup tables for complex spectral energy distributions (such as SIMPL) which are expensive to calculate.

Default: False

sed_prefix

Location of SED tables

Default: None