TRAFICANTE, ALESSIOALESSIOTRAFICANTEDuarte-Cabral, A.A.Duarte-CabralELIA, Davide QuintinoDavide QuintinoELIAFuller, G. A.G. A.FullerMerello, M.M.MerelloMOLINARI, SergioSergioMOLINARIPeretto, N.N.PerettoSCHISANO, EUGENIOEUGENIOSCHISANODI GIORGIO, Anna MariaAnna MariaDI GIORGIO2021-04-212021-04-2120180035-8711http://hdl.handle.net/20.500.12386/30830We tested the validity of the three Larson relations in a sample of 213 massive clumps selected from the Herschel infrared Galactic Plane (Hi-GAL) survey, also using data from the Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey of 3-mm emission lines. The clumps are divided into five evolutionary stages so that we can also discuss the Larson relations as a function of evolution. We show that this ensemble does not follow the three Larson relations, regardless of the clump's evolutionary phase. A consequence of this breakdown is that the dependence of the virial parameter α<SUB>vir</SUB> on mass (and radius) is only a function of the gravitational energy, independent of the kinetic energy of the system; thus, α<SUB>vir</SUB> is not a good descriptor of clump dynamics. Our results suggest that clumps with clear signatures of infall motions are statistically indistinguishable from clumps with no such signatures. The observed non-thermal motions are not necessarily ascribed to turbulence acting to sustain the gravity, but they might be a result of the gravitational collapse at the clump scales. This seems to be particularly true for the most massive (M ≥ 1000 M<SUB>☉</SUB>) clumps in the sample, where exceptionally high magnetic fields might not be enough to stabilize the collapse.STAMPAenArticle10.1093/mnras/sty7982-s2.0-85047124375https://academic.oup.com/mnras/article/477/2/2220/49907192018MNRAS.477.2220TFIS/05 - ASTRONOMIA E ASTROFISICA