Planck Cold Clumps in the λ Orionis Complex. II. Environmental Effects on Core Formation - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles The Astrophysical Journal Supplement Series Year : 2018

Planck Cold Clumps in the λ Orionis Complex. II. Environmental Effects on Core Formation

Hee-Weon Yi
  • Function : Author
Jeong-Eun Lee
  • Function : Author
Tie Liu
  • Function : Author
Kee-Tae Kim
Minho Choi
  • Function : Author
David Eden
  • Function : Author
Neal J. Evans
  • Function : Author
James Di Francesco
Gary Fuller
  • Function : Author
N. Hirano
  • Function : Author
Mika Juvela
  • Function : Author
Sung-Ju Kang
  • Function : Author
Gwanjeong Kim
  • Function : Author
Patrick M. Koch
  • Function : Author
Chang Won Lee
  • Function : Author
Di Li
  • Function : Author
H. -Y. B. Liu
  • Function : Author
Hong-Li Liu
  • Function : Author
Sheng-Yuan Liu
  • Function : Author
Mark G. Rawlings
  • Function : Author
Patrico Sanhueza
  • Function : Author
Archana Soam
  • Function : Author
Ken'Ichi Tatematsu
  • Function : Author
Mark Thompson
  • Function : Author
L. V. Toth
  • Function : Author
Ke Wang
Glenn J. White
  • Function : Author
Yuefang Wu
  • Function : Author
Yao-Lun Yang
  • Function : Author

Abstract

Based on the 850 μm dust continuum data from SCUBA-2 at James Clerk Maxwell Telescope (JCMT), we compare overall properties of Planck Galactic Cold Clumps (PGCCs) in the λ Orionis cloud to those of PGCCs in the Orion A and B clouds. The Orion A and B clouds are well-known active star-forming regions, while the λ Orionis cloud has a different environment as a consequence of the interaction with a prominent OB association and a giant H II region. PGCCs in the λ Orionis cloud have higher dust temperatures (T d = 16.13 ± 0.15 K) and lower values of dust emissivity spectral index (β = 1.65 ± 0.02) than PGCCs in the Orion A (T d = 13.79 ± 0.21 K, β = 2.07 ± 0.03) and Orion B (T d = 13.82 ± 0.19 K, β = 1.96 ± 0.02) clouds. We find 119 substructures within the 40 detected PGCCs and identify them as cores. Out of a total of 119 cores, 15 cores are discovered in the λ Orionis cloud, while 74 and 30 cores are found in the Orion A and B clouds, respectively. The cores in the λ Orionis cloud show much lower mean values of size R = 0.08 pc, column density N(H2) = (9.5 ± 1.2) × 1022 cm-2, number density n(H2) = (2.9 ± 0.4) × 105 cm-3, and mass M core = 1.0 ± 0.3 M compared to the cores in the Orion A [R = 0.11 pc, N(H2) = (2.3 ± 0.3) × 1023 cm-2, n(H2) = (3.8 ± 0.5) × 105 cm-3, and M core = 2.4 ± 0.3 M ] and Orion B [R = 0.16 pc, N(H2) = (3.8 ± 0.4) × 1023 cm-2, n(H2) = (15.6 ± 1.8) × 105 cm-3, and M core = 2.7 ± 0.3 M ] clouds. These core properties in the λ Orionis cloud can be attributed to the photodissociation and external heating by the nearby H II region, which may prevent the PGCCs from forming gravitationally bound structures and eventually disperse them. These results support the idea of negative stellar feedback on core formation.

Dates and versions

insu-03678200 , version 1 (25-05-2022)

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Hee-Weon Yi, Jeong-Eun Lee, Tie Liu, Kee-Tae Kim, Minho Choi, et al.. Planck Cold Clumps in the λ Orionis Complex. II. Environmental Effects on Core Formation. The Astrophysical Journal Supplement Series, 2018, 236, ⟨10.3847/1538-4365/aac2e0⟩. ⟨insu-03678200⟩
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