Testing the Larson relations in massive clumps

A. Traficante, A. Duarte-Cabral, D. Elia, G. A. Fuller, M. Merello, S. Molinari, N. Peretto, E. Schisano, A. Di Giorgio

    Research output: Contribution to journalArticlepeer-review

    81 Downloads (Pure)


    We 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 showthat this ensemble does not followthe three Larson relations, regardless of the clump's evolutionary phase. A consequence of this breakdown is that the dependence of the virial parameter αvir on mass (and radius) is only a function of the gravitational energy, independent of the kinetic energy of the system; thus, αvir 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) clumps in the sample, where exceptionally high magnetic fields might not be enough to stabilize the collapse.

    Original languageEnglish
    Pages (from-to)2220-2242
    Number of pages23
    JournalMonthly Notices of the Royal Astronomical Society
    Issue number2
    Early online date1 May 2018
    Publication statusPublished - 21 May 2018


    • Infrared: Stars
    • Stars: Formation
    • Stars: Kinematics and dynamics
    • Stars: Massive
    • Stars: Statistics
    • Surveys


    Dive into the research topics of 'Testing the Larson relations in massive clumps'. Together they form a unique fingerprint.

    Cite this