J/ApJS/254/14 Planck Cold Clumps in the lambda Orionis complex. III. (Yi+, 2021)
Planck Cold Clumps in the λ Orionis complex.
III. A chemical probe of stellar feedback on cores in the λ Orionis
cloud.
Yi H.-W., Lee J.-E., Kim K.-T., Liu T., Lim B., Tatematsu K.
<Astrophys. J. Suppl. ser., 254, 14 (2021)>
=2021ApJS..254...14Y 2021ApJS..254...14Y
ADC_Keywords: Molecular clouds; Interstellar medium; Star Forming Region;
YSOs; Radio lines; Millimetric/submm sources; Molecular data
Keywords: Star formation; Stellar feedback; Interstellar medium;
Molecular clouds; Photodissociation regions; H II regions;
Chemical abundances
Abstract:
Massive stars have a strong impact on their local environments.
However, how stellar feedback regulates star formation is still under
debate. In this context, we studied the chemical properties of
80 dense cores in the Orion molecular cloud complex composed of the
Orion A (39 cores), B (26 cores), and λ Orionis (15 cores)
clouds using multiple molecular line data taken with the Korean Very
Long Baseline Interferometry Network 21m telescopes. The
λ Orionis cloud has an HII bubble surrounding the O-type star
λ Ori, and hence it is exposed to the ultraviolet (UV)
radiation field of the massive star. The abundances of C2H and HCN,
which are sensitive to UV radiation, appear to be higher in the cores
in the λ Orionis cloud than in those in the Orion A and B
clouds, while the HDCO to H2CO abundance ratios show the opposite
trend, indicating warmer conditions in the λ Orionis cloud. The
detection rates of dense gas tracers such as the N2H+, HCO+, and
H13CO+ lines are also lower in the λ Orionis cloud. These
chemical properties imply that the cores in the λ Orionis cloud
are heated by UV photons from λ Ori. Furthermore, the cores in
the λ Orionis cloud do not show any statistically significant
excess in the infall signature of HCO+ (1-0), unlike those in the
Orion A and B clouds. Our results support the idea that feedback from
massive stars impacts star formation in a negative way by heating and
evaporating dense materials, as in the λ Orionis cloud.
Description:
We carried out single-dish observations with the Korean Very Long
Baseline Interferometry Network (KVN) 21m telescopes at the Yonsei,
Ulsan, and Tamna stations. A multifrequency receiving system is
attached to each telescope with the 22, 44, 86, and 129GHz bands. The
observations toward 80 cores in the λ Orionis, Orion A, and B
clouds were made from 2016 August to 2017 March using several
receivers simultaneously.
The J=1-0 transitions of five molecules (N2H+, HCO+, H13CO+,
C2H, and HCN), including an SiO thermal line (v=0, J=1-0), two
masers (CH3OH 70->61 A+ and H2O 616->523), and H2CO
(21,2->11,1), H213CO (21,2->11,1), and HDCO
(20,2->10,1) lines were observed.
From the Submillimetre Common-User Bolometer Array 2 (SCUBA-2)
Continuum Observations of Pre-protostellar Evolution (SCOPE) project,
we obtained the 850um dust continuum emission maps to estimate column
densities of H2 molecules toward the 80 cores in our sample.
See Section 2.3.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 96 80 Properties of H13CO+, C2H, HCN, and HCO+
lines
table3.dat 80 80 Properties of N2H+, HDCO, and H2CO Lines
table10.dat 72 80 Spectral line velocities, line asymmetry, and
infall rate
table12.dat 95 80 Column densities of seven molecules and H2
toward three molecular clouds
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See also:
II/328 : AllWISE Data Release (Cutri+ 2013)
J/AJ/118/2409 : VRI photometry of λ Ori PMS stars (Dolan+, 1999)
J/A+A/357/1001 : The λ-Orionis ring in CO (Lang+ 2000)
J/AJ/123/387 : VRI phot. of λ Ori star-forming region (Dolan+, 2002)
J/ApJS/155/149 : CH3OH 70-61 A+ maser sources (Kurtz+, 2004)
J/AJ/128/805 : Low-mass stars in Cepheus OB2 region (Sicilia-Aguilar+ 2004)
J/A+A/426/503 : Cat. of high velocity molecular outflows (Update) (Wu+ 2004)
J/ApJ/665/1194 : Dense cores in the Orion A cloud survey (Ikeda+, 2007)
J/ApJ/688/1142 : Star formation in W5: Spitzer observations (Koenig+, 2008)
J/ApJ/702/1615 : CH3OH maser survey of EGOs (Cyganowski+, 2009)
J/ApJ/722/1226 : IR photometry in λ Orionis cluster (Hernandez+, 2010)
J/MNRAS/426/2917 : X-rays sources in Trumpler 37 (Getman+, 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 cat. (Megeath+, 2012)
J/ApJ/756/60 : A 3mm line survey in 37 IR dark clouds (Sanhueza+, 2012)
J/A+A/560/A73 : Horsehead H2CO and CH3OH 30m and PdBI maps (Guzman+, 2013)
J/ApJ/767/36 : APEX observations of HOPS protostars (Stutz+, 2013)
J/MNRAS/443/454 : UBVIHα photometry in NGC 1893 (Lim+, 2014)
J/MNRAS/439/2584 : Southern methanol masers at 36 and 44GHz (Voronkov+, 2014)
J/A+A/575/A87 : Deuteration in massive star formation (Fontani+, 2015)
J/MNRAS/450/1926 : Infall motions in massive star-forming regions (He+, 2015)
J/ApJS/224/5 : Herschel Orion Protostar Survey (HOPS): SEDs (Furlan+, 2016)
J/A+A/594/A28 : Planck Cat. of Galactic cold clumps (PGCC) (Planck+, 2016)
J/ApJ/820/37 : HCO+ & HCN obs. toward PGCCs (Yuan+, 2016)
J/ApJ/834/142 : Gould's Belt Distances Survey. II. OMC (Kounkel+, 2017)
J/AJ/156/84 : APOGEE-2 survey of Orion Complex. II. (Kounkel+, 2018)
J/MNRAS/477/1993 : NGC 1893 stars LSR velocities (Lim+, 2018)
J/ApJS/236/51 : PGCCs in lambda Orionis. II. Cores at 850um (Yi+, 2018)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Cloud Cloud identifier
18- 32 A15 --- Core Core identifier
34- 37 F4.2 K Tpeak1 [0.15/1.63]? The H13CO+ peak temperature
39- 43 F5.2 km/s VLSR1 [1.3/13.5]? The H13CO+ Local Standard
of Rest velocity
45- 48 F4.2 km/s FWHM1 [0.3/2.4]? The H13CO+ Full-Width at Half
Maximum
50- 53 F4.2 K Tpeak2 [0.09/1.1]? The C2H peak temperature
55- 59 F5.2 km/s VLSR2 [1.5/13.7]? The C2H Local Standard of Rest
velocity
61- 64 F4.2 km/s FWHM2 [0.04/2.2]? The C2H Full-Width at Half Maximum
66- 69 F4.2 K Tpeak3 [0.1/7.7]? The HCN peak temperature
71- 75 F5.2 km/s VLSR3 [1.6/13.8]? The HCN Local Standard of Rest
velocity
77- 80 F4.2 km/s FWHM3 [0.3/4.1]? The HCN Full-Width at Half Maximum
82- 85 F4.2 K Tpeak4 [0.26/4.9]? The HCO+ peak temperature
87- 91 F5.2 km/s VLSR4 [1.2/14.4]? The HCO+ Local Standard of
Rest velocity
93- 96 F4.2 km/s FWHM4 [0.19/4]? The HCO+ Full-Width at Half Maximum
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Cloud Cloud identifier
18- 32 A15 --- Core Core identifier
34- 37 F4.2 K Tpeak5 [0.1/2.91]? The N2H+ peak temperature
39- 43 F5.2 km/s VLSR5 [0.3/12.5]? The N2H+ Local Standard of
Rest velocity
45- 48 F4.2 km/s FWHM5 [0.2/1.4]? The N2H+ Full-Width at Half
Maximum
50- 53 F4.2 K Tpeak6 [0.08/0.6]? The HDCO peak temperature
55- 59 F5.2 km/s VLSR6 [1.4/14.4]? The HDCO Local Standard of
Rest velocity
61- 64 F4.2 km/s FWHM6 [0.27/1.5]? The HDCO Full-Width at Half Maximum
66- 69 F4.2 K Tpeak7 [0.13/2.1]? The H2CO peak temperature
71- 75 F5.2 km/s VLSR7 [1.3/13.9]? The H2CO Local Standard of
Rest velocity
77- 80 F4.2 km/s FWHM7 [0.4/2.92]? The H2CO Full-Width at Half Maximum
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Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Cloud Cloud identifier
18- 32 A15 --- Core Core identifier
34- 38 F5.2 km/s Vthick [1.2/14.4]? Peak velocity of an optically
thick line
40- 44 F5.2 km/s Vthin [1.3/13.5]? Peak velocity of an optically
thin line
46- 49 F4.2 km/s DelVthin [0.3/2.4]? Line width of the optically
thin line
51- 57 F7.2 --- deltav [-22/1.1]? The (Vthick-Vthin)/DelVthin
value
59- 65 A7 --- Profile Profile line asymmetry type
67- 72 F6.2 10-6Msun/yr dM/dt [2.9/139]? Infall rate
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Byte-by-byte Description of file: table12.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Cloud Cloud identifier
18- 32 A15 --- Core Core identifier
34- 40 A7 --- YSO Associated YSO
42- 46 F5.2 10+12/cm2 N2H+ [0.37/34.3]? N2H+ column density
48- 53 F6.2 10+12/cm2 HCO+ [0.4/165.2]? HCO+ column density
55- 58 F4.2 10+12/cm2 H13CO+ [0.2/7.9]? H13CO+ column density
60- 65 F6.2 10+12/cm2 HCN [2.6/109.5]? HCN column density
67- 71 F5.2 10+14/cm2 C2H [0.8/31.1]? C2H column density
73- 77 F5.2 10+13/cm2 H2CO [0.28/28.8]? H2CO column density
79- 83 F5.2 10+12/cm2 HDCO [0.38/11.6]? HDCO column density
85- 89 F5.2 10+22/cm2 H230 [0.2/28.4] H2 column density over 30 arcsec (1)
91- 95 F5.2 10+22/cm2 H220 [1.2/51.8] H2 column density over 20 arcsec (2)
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Note (1): The 850 micron dust continuum maps were smoothed to calculate the
abundance ratios of N2H+, HCO+, H13CO+, HCN, and C2H
molecules.
Note (2): The 850 micron dust continuum maps were smoothed to calculate the
abundance ratios of H2CO and HDCO molecules.
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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 II. 2018ApJS..236...51Y 2018ApJS..236...51Y Cat. J/ApJS/236/51
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Jul-2021