Correlation between non-thermal motions (σ_NT) and the mass-per-unit-length (m_lin) in the NGC 1333 fibers (red squares). The blue dashed line denotes the critical m_lin for a filament in hydrostatic equilibrium, , with , separating the subcritical (i.e., m_lin ≤ m_crit and supercritical regimes (i.e., m_lin>m_crit). The vertical error bars correspond to the 1σ variations for the observed σ_NT in each fiber.