J/A+A/645/A94 NGC 2264 clumps column densities (Nony+, 2021)
Mass segregation and sequential star formation in NGC 2264 revealed by Herschel.
Nony T., Robitaille J.-F., Motte F., Gonzalez M., Joncour I., Moraux E.,
Men'shchikov A., Didelon P., Louvet F., Buckner A.S.M., Schneider N.,
Lumsden S.L., Bontemps S., Pouteau Y., Cunningham N., Fiorellino E.,
Oudmaijer R., Andre P., Thomasson B.
<Astron. Astrophys. 645, A94 (2021)>
=2021A&A...645A..94N 2021A&A...645A..94N (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Millimetric/submm sources
Keywords: ISM: structure - stars: formation - methods: statistical -
open clusters and associations: individual: NGC 2264 - ISM: clouds
Abstract:
The mass segregation of stellar clusters could be primordial rather
than dynamical. Despite the abundance of studies of mass segregation
for stellar clusters, those for stellar progenitors are still scarce,
so the question on the origin and evolution of mass segregation is
still open. Our goal is to characterize the structure of the NGC 2264
molecular cloud and compare the populations of clumps and young
stellar objects (YSOs) in this region whose rich YSO population has
shown evidence of sequential star formation. We separated the Herschel
column density map of NGC 2264 in three subregions and compared their
cloud power spectra using a multiscale segmentation technique. We
identified in the whole NGC 2264 cloud a population of 256 clumps with
typical sizes of ∼0.1pc and masses ranging from 0.08M☉ to
53M☉. Although clumps have been detected all over the cloud, the
central subregion of NGC 2264 concentrates most of the massive, bound
clumps. The local surface density and the mass segregation ratio
indeed indicate a strong degree of mass segregation for the 15 most
massive clumps, with a median Sigma6 three time that of the whole
clumps population and LambdaMSR about 8. We showed that this cluster
of massive clumps is forming within a high-density cloud ridge, itself
formed and probably still fed by the high concentration of gas
observed on larger scales in the central subregion. The time sequence
obtained from the combined study of the clump and YSO populations in
NGC 2264 suggests that the star formation started in the northern
subregion, that it is now actively developing at the center and will
soon start in the southern subregion. Taken together, the cloud
structure and the clump and YSO populations in NGC 2264 argue for a
dynamical scenario of star formation.
Description:
Column density and informations for the 256 clumps found in NGC 2264.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 137 256 Column density and informations for the 256
clumps found in NGC 2264
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/256] GETSF sequential number
5- 15 F11.7 deg RAdeg Right ascension (J2000)
17- 26 F10.7 deg DEdeg Declination (J2000)
28- 31 F4.1 arcsec AFWHM FWHM major axis
33- 36 F4.1 arcsec BFWHM FWHM minor axis
38- 42 F5.1 deg PA Position angle
44- 48 F5.1 --- Signi Detection Significance
50- 56 E7.1 10+21cm-2 NH2peak Peak column density
58- 64 E7.1 10+21cm-2 e_NH2peak Peak column density uncertainty
66- 72 E7.1 10+21cm-2 NH2int Integrated column density
74- 80 E7.1 10+21cm-2 e_NH2int Integrated column density uncertainty
82- 88 E7.1 pc FWHMdec FWHM size deconvolved from the 18.2 arcsec
beam
90- 93 F4.1 K Temp Temperature
95- 97 F3.1 K e_Temp Temperature uncertainty
99-105 E7.1 solMass Mass Mass calculated from integrated column
density
107-113 E7.1 solMass e_Mass Mass uncertainty
115-121 E7.1 --- Bo Bonnor-Ebert ratio, FWHMdec/Rbe
123-129 E7.1 10+21cm-2 NH2back Background column density
131-137 E7.1 10+21cm-2 e_NH2back Background column density uncertainty
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Acknowledgements:
Thomas Nony, t.nony(at)irya.unam.mx
(End) Patricia Vannier [CDS] 16-Nov-2020