Open AccessTurbulence in Class 0 and I protostellar envelopes
Author(s) -
WardThompson D.,
Hartmann L.,
Nutter D. J.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.08680.x
Subject(s) - protostar , physics , astrophysics , turbulence , class (philosophy) , line (geometry) , star formation , stars , astronomy , meteorology , geometry , mathematics , artificial intelligence , computer science
We estimate the levels of turbulence in the envelopes of class 0 and I protostars using a model based on measurements of the peak separation of double‐peaked asymmetric line profiles. We use observations of 20 protostars of both class 0 and I taken in the HCO + (J = 3 → 2) line that show the classic double‐peaked profile. We find that some class 0 sources show high levels of turbulence, whilst others demonstrate much lower levels. In class I protostars, we find predominantly low levels of turbulence. The observations are consistent with a scenario in which class 0 protostars form in a variety of environments and subsequently evolve into class I protostars. The data do not appear to be consistent with a recently proposed scenario in which class 0 protostars can only form in extreme environments.