Particle tracers

Over the course of the simulation, the gas, sink and star particles record some information about their evolution. These are updated for a given particle every time it is active. The GEAR tracers module is located in the directory src/tracers/GEAR/. To enable GEAR tracers, add --with-tracers=GEAR to your configuration options.

Currently, GEAR tracers are only implemented for sink particles.

Sink tracers

The tracers track the long-term evolution of the sinks’ accretion rates and SFR between different time slices. These tracers are used to capture the high-frequency variability of the the accretion rate and SFR that might be lost between snapshots.

The time slices are specified by Snapshots:recording_triggers_sink. By default, the number of recording time slices is 3. You can change this value in src/tracers_triggers.h and then recompile the code. These outputs are arrays of length num_snapshot_triggers_sink.

Name

Description

Units

Comments

AveragedAccretionRates

Accretion rates averaged over the
snapshot trigger intervals

[U_M U_T^{-1}]

Averaged over the period set by the
first N snapshot triggers.

AveragedStarFormationRates

Star formation rates averaged over the
snapshot trigger intervals

[U_M U_T^{-1}]

Averaged over the period set by the
first N snapshot triggers.