Probing Velocity Structures of Protostellar Envelopes: Infalling and Rotating Envelopes within Turbulent Dense Cores

Abstract We have observed the three low-mass protostars, IRAS 15398−3359, L1527 IRS, and TMC-1A, with ALMA 12 m array, ACA 7 IRAM-30 APEX telescopes in C 18 O J = 2–1 emission. Overall, emission shows clear velocity gradients at radii of ∼100–1000 au, which likely originate from rotation envelopes, while are less structures more perturbed on scales ∼1000–10,000 au. 15398−3359 IRS show a break ∼1200 ∼1700 au radial profile peak velocity, respectively. The is proportional to r −1.38 or −1.7 within radius, can be interpreted as indicating rotational motion envelope degree contamination by gas motions larger spatial scales. follows v ∝ 0.68 0.46 outside similar / M – R relation dense cores. TMC-1A exhibits that not consistent nor relation. origin investigated examining correlations deviation ( δ ) scale τ two sources. obtained correlations, ∼0.6 , scaling law predicted turbulence models, may suggest large-scale turbulence.