J/A+A/696/A11 ALMA-IMF XVII (Valeille-Manet+, 2025)
ALMA-IMF. XVII.
Census and lifetime of high-mass prestellar cores in 14 massive protoclusters.
Valeille-Manet M., Bontemps S., Csengeri T., Nony T., Motte F., Stutz A.M.,
Gusdorf A., Ginsburg A., Galvan-Madrid R., Sanhueza P., Bonfand M.,
Brouillet N., Dell'Ova P., Louvet F., Cunningham N., Fernandez-Lopez M.,
Herpin F., Wyrowski F., Alvarez-Gutierrez R.H., Armante M., Guzman A.E.,
Kessler N., Koley A., Salinas J., Yoo T., Bronfman L., Le Nestour N.
<Astron. Astrophys. 696, A11 (2025)>
=2025A&A...696A..11V 2025A&A...696A..11V (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region ; Infrared sources ; Interstellar medium ;
YSOs; Stars, masses
Keywords: stars: formation - stars: massive - stars: protostellar -
ISM: clouds - ISM: jest and outflows
Abstract:
High-mass prestellar cores are extremely rare. Until recently, the
search for such objects has been hampered by small sample sizes,
leading to large ambiguities in their lifetimes and hence the
conditions in the cores in which high-mass stars (>8M☉) form.
Here we leverage the large sample (∼580 cores) detected in the
ALMA-IMF survey to identify both protostellar and prestellar cores to
estimate their relative lifetimes. We used CO and SiO outflows to
identify protostellar cores. We present a new automated method based
on aperture line emission and background subtraction to systematically
detect outflows associated with each of the 141 most massive cores.
Massive cores that are not driving an outflow in either tracer are
identified as prestellar. After careful scrutiny of the sample, we
derived statistical lifetime estimates for the prestellar phase. Our
automated method allows the efficient detection of CO and SiO outflows
and has a performance efficiency similar to that of more cumbersome
classical techniques. We identified 30 likely prestellar cores with
M>8M☉, of which 12 have core masses M>16M☉. The latter
group contains the best candidates for high-mass star precursors.
Moreover, most of these 12 high-mass prestellar cores are located
inside the crowded central regions of the protoclusters, where most
high-mass stars are expected to form. Using the relative ratios of
prestellar to protostellar cores, and assuming a high-mass
protostellar lifetime of 300kyr, we derive a prestellar core lifetime
of 120kyr to 240kyr for cores with masses 8M☉<M<16M☉. For
30M☉<M<55M☉, the lifetimes range from 50kyr to 100kyr. The
spread in timescales reflects different assumptions for scenarios for
the mass reservoir evolution. These timescales are remarkably long
compared to the 4kyr to 15kyr free-fall time of the cores. Hence, we
suggest that high- mass cores live ∼10 to 30 free-fall times, with a
tentative trend of a slight decrease with core mass. Such high ratios
suggest that the collapse of massive cores is slowed down by
non-thermal support of turbulent, magnetic or rotational origin at or
below the observed scale.
Description:
Table A.1 presents the complete sample of PSC candidates, including
their host region, number, coordinates (J2000), mass, size, density,
corresponding free-fall time, and location status (clustered or
isolated).
Table C.1 presents the 100 cores above 4M☉ classified as
protostellar listed with their host region, number, coordinates
(J2000), mass, temperature and size.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 79 42 List of the 42 prestellar core candidates
tablec1.dat 58 100 List of the 100 protostellar core candidates
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See also:
J/A+A/662/A9 : 15 dense molecular cloud regions ALMA images (Ginsburg+, 2022)
J/A+A/664/A26 : W43-MM2+MM3 ministarburst ALMA data (Pouteau+, 2022)
J/A+A/674/A75 : W43-MM1 and W43-MM2+MM3 ALMA datacubes (Nony+, 2023)
J/A+A/687/A217 : 15 massive protoclusters point-process mapping
(Dell'Ova+, 2024)
J/A+A/690/A33 : Core mass function in high-mass star formation (Louvet+, 2024)
J/A+A/694/A24 : ALMA-IMF XVI (Motte+, 2025)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Region Protocluster name in the ALMA-IMF sample
10- 11 A2 --- ID Identification number of the source within
the region
13- 23 F11.7 deg RAdeg Right Ascension of the source (J2000)
25- 35 F11.7 deg DEdeg Declination of the source (J2000)
37- 40 F4.1 Msun Mass Mass of the source (1)
42- 45 F4.1 Msun b_Mass Mass lower limit (1)
47- 50 F4.1 Msun B_Mass Mass upper limit (1)
52- 57 F6.1 au Size Deconvolved FWHM of the source
59- 63 F5.1 10+6cm-3 Dens Volume density of the source
65- 68 F4.1 10+6cm-3 e_Dens Uncertainty on the density
70- 73 F4.1 kyr tff Free-fall time of the source
75- 77 F3.1 kyr e_tff Uncertainty on the free-fall time
79 A1 --- Loc [CI] Location of the source (2)
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Note (1): Mean masses of the candidates with their range using the
non-corrected PPMAP dust temperature (see Dell'Ova et al.,
2024A&A...687A.217D 2024A&A...687A.217D) and 20K as upper and lower limits in temperature.
Note (2): Location of the source with C meaning clustered and
I meaning isolated, based on the criteria described in Sect. 4.5 of the paper.
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Region Protocluster name in the ALMA-IMF sample
10- 11 A2 --- ID Identification number of the source within the
region
13- 23 F11.7 deg RAdeg Right Ascension of the source (J2000)
25- 35 F11.7 deg DEdeg Declination of the source (J2000)
37- 41 F5.1 Msun Mass Mass of the source (1)
43- 45 F3.1 Msun e_Mass Uncertainty on the mass (1)
47- 51 F5.1 K Temp Temperature of the source (2)
53- 58 F6.1 au Size Deconvolved FWHM of the source
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Note (1): Mass of the protostellar core candidates obtained with the PPMAP
70um corrected dust temperatures (see Dell'Ova et al., 2024A&A...687A.217D 2024A&A...687A.217D)
Note (2): PPMAP 70um corrected dust temperatures (see Dell'Ova et al.,
2024A&A...687A.217D 2024A&A...687A.217D)
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Acknowledgements:
Maxime Valeille-Manet, maxime.valeille-manet(at)univ-grenoble-alpes.fr
References:
Motte et al., Paper I 2022A&A...662A...8M 2022A&A...662A...8M
Ginsburg et al., Paper II 2022A&A...662A...9G 2022A&A...662A...9G, Cat. J/A+A/662/A9
Pouteau et al., Paper III 2022A&A...664A..26P 2022A&A...664A..26P, Cat. J/A+A/664/A26
Brouillet et al., Paper IV 2022A&A...665A.140B 2022A&A...665A.140B
Nony et al., Paper V 2023A&A...674A..75N 2023A&A...674A..75N, Cat. J/A+A/674/A75
Pouteau et al., Paper VI 2023A&A...674A..76P 2023A&A...674A..76P
Cunningham et al., Paper VII 2023A&A...678A.194C 2023A&A...678A.194C
Diaz-Gonzalez et al., Paper VIII 2023ApJS..269...55D 2023ApJS..269...55D
Towner et al., Paper IX 2024ApJ...960...48T 2024ApJ...960...48T
Armante et al., Paper X 2024A&A...686A.122A 2024A&A...686A.122A
Bonfand et al., Paper XI 2024A&A...687A.163B 2024A&A...687A.163B
Dell'Ova et al., Paper XII 2024A&A...687A.217D 2024A&A...687A.217D,Cat. J/A+A/687/A217
Alvarez-Gutierrez et al., Paper XIII 2024A&A...689A..74A 2024A&A...689A..74A
Galvan-Madrid et al., Paper XIV 2024ApJS..274...15G 2024ApJS..274...15G
Louvet et al., Paper XV 2024A&A...690A..33L 2024A&A...690A..33L, Cat. J/A+A/690/A33
Motte et al., Paper XVI 2025A&A...694A..24M 2025A&A...694A..24M, Cat. J/A+A/694/A24
(End) Patricia Vannier [CDS] 06-Mar-2025