J/ApJS/236/51 PGCCs in lambda Orionis complex. II. Cores at 850um (Yi+, 2018)
Planck Cold Clumps in the λ Orionis complex.
II. Environmental effects on core formation.
Yi H.-W., Lee J.-E., Liu T., Kim K.-T., Choi M., Eden D., Evans II N.J.,
Di Francesco J., Fuller G., Hirano N., Juvela M., Kang S.-J., Kim G.,
Koch P.M., Lee C.W., Li Di, Liu H.-Y.B., Liu H.-L., Liu S.-Y.,
Rawlings M.G., Ristorcelli I., Sanhueza P., Soam A., Tatematsu K.,
Thompson M., Toth L.V., Wang Ke, White G.J., Wu Y., Yang Y.-L.
(The JCMT Large Program "SCOPE" Collaboration)
(The TRAO Key Science Program "TOP" Collaboration)
<Astrophys. J. Suppl. Ser., 236, 51 (2018)>
=2018ApJS..236...51Y 2018ApJS..236...51Y
ADC_Keywords: Molecular clouds; Interstellar medium; Star Forming Region;
YSOs; Photometry, millimetric/submm; Stars, masses
Keywords: ISM: clouds ; stars: formation ; submillimeter: ISM
Abstract:
Based on the 850µm 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 HII region. PGCCs in the
λ Orionis cloud have higher dust temperatures
(Td=16.13±0.15K) and lower values of dust emissivity spectral
index (β=1.65±0.02) than PGCCs in the Orion A
(Td=13.79±0.21K, β=2.07±0.03) and Orion B
(Td=13.82±0.19K, 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=0.08pc, column density
N(H2)=(9.5±1.2)x1022cm-2, number density
n(H2)=(2.9±0.4)x105cm-3, and mass Mcore=1.0±0.3M☉
compared to the cores in the Orion A [R=0.11pc,
N(H2)=(2.3±0.3)x1023cm-2, n(H2)=(3.8±0.5)x105cm-3, and
Mcore=2.4±0.3M☉] and Orion B [R=0.16pc,
N(H2)=(3.8±0.4)x1023cm-2, n(H2)=(15.6±1.8)x105cm-3,
and Mcore=2.7±0.3M☉] 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.
Description:
As part of the legacy survey, "SCUBA-2 Continuum Observations of
Pre-protostellar Evolution" (SCOPE; Liu+ 2018ApJS..234...28L 2018ApJS..234...28L and
Eden+ 2019MNRAS.485.2895E 2019MNRAS.485.2895E ; proposal code: M16AL003), we observed
58 Planck Galactic Cold Clumps (PGCCs) in the "CV Daisy" mapping mode,
which is suitable for small and compact sources with sizes of less
than 3' at 450 and 850um with the Submillimetre Common-User Bolometer
Array 2 (SCUBA-2) at the 15m James Clerk Maxwell Telescope (JCMT).
We also included archival data of 38 PGCCs located in the Orion A and
B clouds from the JCMT Science Archive hosted by the Canadian
Astronomical Data Centre (CADC).
Table 1 lists information about the 96 PGCCs.
We also included data from the Wide-Field Infrared Survey Explorer
(WISE) AllWISE catalog (Wright+ 2010, see II/328).
Finally, we obtained 119 cores within the 40 detected PGCCs in the
Orion complex. In the λ Orionis cloud, there are 8 detected
PGCCs, from which 15 cores are identified. The Orion A cloud has
74 cores in 23 PGCCs, and the Orion B cloud has 30 cores in 9 PGCCs.
The list of cores in each cloud is found in Tables 2-4.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 71 96 Planck Galactic Cold Clumps (PGCCs) observed
with SCUBA-2 in the Orion complex
table2.dat 139 15 Properties of cores detected at 850um and
associated YSOs in the λ Orionis cloud
table3.dat 139 74 Properties of cores detected at 850um and
associated YSOs in the Orion A cloud
table4.dat 139 30 Properties of cores detected at 850um and
associated YSOs in the Orion B cloud
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See also:
B/jcmt : Jame Clerk Maxwell Telescope Science Archive (CADC, 2003)
II/328 : AllWISE Data Release (Cutri+ 2013)
J/ApJ/428/693 : Rosette Nebula and Maddalena Cloud structures (Williams+ 1994)
J/A+A/357/1001 : The λ-Orionis ring in CO (Lang+ 2000)
J/AJ/121/2124 : λ Ori pre-main-sequence stars photometry (Dolan+, 2001)
J/AJ/123/387 : VRI phot. of λ Ori star-forming region (Dolan+, 2002)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/AJ/144/31 : Spitzer+2MASS phot. of protostar candidates (Kryukova+, 2012)
J/ApJS/202/4 : Planck cold clumps survey in the Orion complex (Liu+, 2012)
J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)
J/ApJ/767/36 : APEX observations of HOPS protostars (Stutz+, 2013)
J/A+A/584/A94 : Galactic cold cores. VI. Herschel fields (Juvela+, 2015)
J/ApJS/224/5 : Herschel Orion Protostar Survey (HOPS): SEDs (Furlan+, 2016)
J/A+A/594/A28 : Planck Catalog of Galactic cold clumps (PGCC) (Planck+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Cloud Cloud name
15- 27 A13 --- PGCC PGCC identifier (GLLL.ll+BB.bbAN)
28 A1 --- m_PGCC Component on PGCC
30- 31 I2 h RAh [5] Hour of right ascension (J2000)
33- 34 I2 min RAm [10/57] Minute of right ascension (J2000)
36- 40 F5.2 s RAs Second of right ascension (J2000)
42 A1 --- DE- Sign of declination (J2000)
43- 44 I2 deg DEd Degree of declination (J2000)
46- 47 I2 arcmin DEm Arcminute of declination (J2000)
49- 53 F5.2 arcsec DEs Arcsecond of declination (J2000)
55- 61 A7 --- Obs Observation source
63- 65 A3 --- Det Detection
67- 71 F5.2 mJy/beam rms [6.6/64.2] Root mean square
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Byte-by-byte Description of file: table[234].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- PGCC PGCC identifier (GLLL.ll+BB.bbAN),
as in Table 1
16- 17 A2 --- ID Core identifier (1)
24- 35 A12 --- OT Object type (starless or protostellar)
37- 38 I2 h RAh [5] Hour of right ascension (J2000)
40- 41 I2 min RAm [18/56] Minute of right ascension (J2000)
43- 47 F5.2 s RAs Second of right ascension (J2000)
49 A1 --- DE- Sign of declination (J2000)
50- 51 I2 deg DEd Degree of declination (J2000)
53- 54 I2 arcmin DEm Arcminute of declination (J2000)
56- 60 F5.2 arcsec DEs Arcsecond of declination (J2000)
62- 65 F4.2 pc Size [0.01/2.3] Core size
67- 71 F5.1 10+22cm-2 NH2 [2.5/116.6] H2 column density N(H2)
73- 76 F4.1 10+22cm-2 e_NH2 [0.1/19.8] NH2 uncertainty
78- 81 F4.1 10+5cm-3 nH2 [0.5/40.8] Beam-averaged hydrogen column
density (2)
83- 85 F3.1 10+5cm-3 e_nH2 [0.1/4.7] nH2 uncertainty
87- 91 F5.2 Msun Mass [0.07/12.25] Core mass
93- 96 F4.2 Msun e_Mass [0.01/3.2] Mass uncertainty
98-101 F4.2 Msun MJ [0.01/3.29]? Jeans mass
103-106 F4.2 Msun e_MJ [0.01/1.6]? MJ uncertainty
108-112 F5.2 Lsun Lbol [0.13/41.62]? Bolometric luminosity
of associated YSOs
114-117 F4.2 Lsun e_Lbol [0.01/7.7]? Lbol uncertainty
119-123 F5.1 K Tbol [19.7/699.6]? Bolometric temperature
of associated YSOs
125-128 F4.1 K e_Tbol [0.1/21.7]? Tbol uncertainty
130-134 F5.2 --- alpha [-0.28/2.67]? 3.6-22um spectral index
α3.6-22 of associated YSOs
136-139 A4 --- Class Object class of associated YSOs
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Note (1): M=Middle; names as given in Paper III (Yi+, 2021, J/ApJS/254/14);
note added by CDS.
Note (2): The mean density of the core was calculated using the beam-averaged
hydrogen column density nH2=N(H2)/R (Equation 2) where the core
diameter R is defined as R=(a.b)0.5 where a and b are the major and
minor axes (full width at half maximum, FWHM) of the fitting in Section 3.2.
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History:
From electronic version of the journal
References:
Liu et al. Paper I. 2016ApJS..222....7L 2016ApJS..222....7L
Yi et al. Paper III. 2021ApJS..254...14Y 2021ApJS..254...14Y Cat. J/ApJS/254/14
(End) Emmanuelle Perret [CDS] 03-Feb-2021