GMC Lifecycle Model Explorer

Six free parameters in physical time. Unlike the simplified model, shape is not something you set here — it emerges from the ratios β = τ_fb/τ_acc and j₀ = Ṁ_D,0/D_∞, shown live below.

Ṁ_D(t) = Ṁ_D,0 + D_∞[1 − e^−t/τfb] · Ṁ_F(t) = a (M(t)/10⁵)^γ e^−t/τacc

Parameters

Controls

Plot against phase s instead of time Overlay stacked AREPO data for the nearest mass bin

Pin a reference, then raise γ and lower τ_acc. The curve returns almost exactly to the reference — that is the degeneracy that makes these two parameters hard to measure separately. Hover either plot to read off t and s along the model track.

—

β = τfb/τacc—

j₀ = Ṁ_D,0/D∞—

β·j₀—

u_turn—

t_cross—

rms vs data—

Ṁ and cloud mass against time

Ṁ_F model Ṁ_D model cloud mass (data, right axis) stacked data pinned reference

Trajectory through the Ṁ_F–Ṁ_D plane

model track pinned reference stacked data Ṁ_F = Ṁ_D ◯ t = 0 ★ crossing

Ṁ_F is driven by the measured mass history M(t) of the selected bin, so the mass curve is data, not a prediction. The best fits loaded by the button vary wildly between bins (τ_fb from 3 to 108 Myr across the eight) — that instability is real, and is why the simplified model fixes the shape constants instead.

Parameters

Controls

Ṁ and cloud mass against time

Trajectory through the ṀF–ṀD plane

Trajectory through the Ṁ_F–Ṁ_D plane