J/MNRAS/477/2220 Larson relations in massive clumps (Traficante+, 2018)
Testing the Larson relations in massive clumps.
Traficante A., Duarte-Cabral A., Elia D., Fuller G.A., Merello M.,
Molinari S., Peretto N., Schisano E., Di Giorgio A.
<Mon. Not. R. Astron. Soc., 477, 2220-2242 (2018)>
=2018MNRAS.477.2220T 2018MNRAS.477.2220T (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar
Keywords: surveys - stars: formation - stars: kinematics and dynamics -
stars: massive - stars: statistics - infrared: stars
Abstract:
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 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 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≥1000M☉) clumps in the sample, where exceptionally
high magnetic fields might not be enough to stabilize the collapse.
Description:
We have discussed the validity of the three Larson relations and the
implications of the results for a large sample of 213 massive clumps
at different evolutionary stages. These clumps have been obtained by
combining the Hi-GAL catalogue (Elia et al., 2017, Cat.
J/MNRAS/471/100) with the MALT90 survey of 3-mm emission lines
(Jackson et al., 2013PASA...30...57J 2013PASA...30...57J ). They have been selected to be
a sample of sources with well-known distances, dust emission
properties and N2H+ (1-0) emission, the latter used to extract the
gas kinematics. The sample has been divided into five evolutionary
stages, and we have obtained 14 starless, 12 protostar MIR dark, 106
protostar MIR bright, 25 YSOs and 56 HII regions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 82 213 Properties of the 213 clumps analysed in this work
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See also:
J/MNRAS/471/100 : Hi-GAL compact source catalog. -71.0<l<67.0 (Elia+, 2017)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Clump name (GLLL.lll+BB.bbb)
17- 23 F7.3 deg GLON Galactic longitude
25- 31 F7.3 deg GLAT Galactic latitude
33- 36 F4.2 pc Rad Clump radius defined by the Cutex fit at 250um
38- 41 F4.1 K T Clump temperature (1)
43- 47 I5 Msun Mass Clump mass (1)
49- 54 I6 Lsun L Clump luminosity (1)
56- 59 F4.2 g/cm2 Sigma Clump surface density
61- 63 F3.1 km/s sigma Clump velocity dispersion (2)
65- 68 F4.1 --- alphavir Virial parameter
70- 82 A13 --- Evol Evolution phase (3)
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Note (1): The clump temperature, mass and luminosity are obtained from
the SED fitting.
Note (2): velocity dispersion obtained from the N2H+ (1-0) emission.
Note (3): The determination of the clump evolutionary phase is discussed in
Section 3.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-Jun-2021