The Power Spectrum of Turbulence in NGC 1333: Outflows or Large-Scale Driving?

TL;DR

This study analyzes the turbulence in NGC 1333 using the VCS method, finding a power-law energy spectrum that suggests large-scale processes, rather than stellar outflows, primarily drive the turbulence.

Contribution

The paper applies the VCS method to observational data and demonstrates that turbulence in NGC 1333 is not mainly driven by stellar outflows, challenging previous assumptions.

Findings

Turbulent energy spectrum follows a power law with slope 1.85.

No spectral flattening observed at the outflow injection scale.

Turbulence appears driven by large-scale processes, not outflows.

Abstract

Is the turbulence in cluster-forming regions internally driven by stellar outflows or the consequence of a large-scale turbulent cascade? We address this question by studying the turbulent energy spectrum in NGC 1333. Using synthetic 13CO maps computed with a snapshot of a supersonic turbulence simulation, we show that the VCS method of Lazarian and Pogosyan provides an accurate estimate of the turbulent energy spectrum. We then apply this method to the 13CO map of NGC 1333 from the COMPLETE database. We find the turbulent energy spectrum is a power law, E(k) k^-beta, in the range of scales 0.06 pc < ell < 1.5 pc, with slope beta=1.85\pm 0.04. The estimated energy injection scale of stellar outflows in NGC 1333 is ell_inj 0.3 pc, well resolved by the observations. There is no evidence of the flattening of the energy spectrum above the scale ell_inj predicted by outflow-driven simulations and analytical models. The power spectrum of integrated intensity is also a nearly perfect power law in the range of scales 0.16 pc < ell < 7.9 pc, with no feature above ell_inj. We conclude that the observed turbulence in NGC 1333 does not appear to be driven primarily by stellar outflows.