J/ApJ/774/73 ALMA CO observations of 30 Dor (Indebetouw+, 2013)
ALMA resolves 30 Doradus: sub-parsec molecular cloud structure near the
closest super star cluster.
Indebetouw R., Brogan C., Chen C.-H.R., Leroy A., Johnson K., Muller E.,
Madden S., Cormier D., Galliano F., Hughes A., Hunter T., Kawamura A.,
Kepley A., Lebouteiller V., Meixner M., Oliveira J.M., Onishi T.,
Vasyunina T.
<Astrophys. J., 774, 73 (2013)>
=2013ApJ...774...73I 2013ApJ...774...73I
ADC_Keywords: Molecular clouds ; Radio lines ; Velocity dispersion ;
Millimetric/submm sources
Keywords: ISM: clouds; ISM: individual: 30 Doradus nebula;
ISM: structure; Magellanic Clouds; radio lines: ISM; stars: protostars
Abstract:
We present Atacama Large (sub)Millimeter Array observations of 30
Doradus - the highest resolution view of molecular gas in an
extragalactic star formation region to date (∼0.4pcx0.6pc). The
30Dor-10 cloud north of R136 was mapped in 12CO 2-1, 13CO 2-1,
C18O 2-1, 1.3mm continuum, the H30α recombination line, and
two H2CO 3-2 transitions. Most 12CO emission is associated with
small filaments and clumps (≲1pc, ∼103M☉ at the current
resolution). Some clumps are associated with protostars, including
"pillars of creation" photoablated by intense radiation from R136.
Emission from molecular clouds is often analyzed by decomposition into
approximately beam-sized clumps. Such clumps in 30 Doradus follow
similar trends in size, linewidth, and surface density to Milky Way
clumps. The 30 Doradus clumps have somewhat larger linewidths for a
given size than predicted by Larson's scaling relation, consistent
with pressure confinement. They extend to a higher surface density at
a given size and linewidth compared to clouds studied at 10 pc
resolution. These trends are also true of clumps in Galactic
infrared-dark clouds; higher resolution observations of both
environments are required. Consistency of clump masses calculated from
dust continuum, CO, and the virial theorem reveals that the CO
abundance in 30 Doradus clumps is not significantly different from the
Large Magellanic Cloud mean, but the dust abundance may be reduced by
∼2. There are no strong trends in clump properties with distance from
R136; dense clumps are not strongly affected by the external radiation
field, but there is a modest trend toward lower dense clump filling
fraction deeper in the cloud.
Description:
The GMC 30Dor-10, north of R136 in 30 Doradus, was observed with ALMA,
in 2011 Dec 31 and 2012 Jan 11, during Early Science Cycle 0, using
the 1.3mm Band 6 receivers. The spectral setup included 12CO 2-1
(230.538GHz rest frequency), 13CO 2-1 (220.399GHz), the H30α
radio recombination line (RRL; 231.90093GHz) and C18O 2-1
(219.560GHz).
Our single-dish observations were made on 2011 October 21-27, 29, 30
and December 3, 4, 12, and 13 with the 12m APEX telescope.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 126 103 Clump properties
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See also:
II/187 : 30 Doradus OB Associations (Parker 1992)
J/ApJS/197/16 : CO observations of LMC molecular clouds (MAGMA). (Wong+, 2011)
J/ApJS/196/18 : CO survey of galactic molecular clouds. II. (Bieging+, 2011)
J/ApJS/191/160 : 3D spectroscopy in 30 Dor (Pellegrini+, 2010)
J/ApJ/723/492 : GRS molecular clouds physical properties (Roman-Duval+, 2010)
J/ApJS/184/172 : High- and intermediate-mass YSOs in the LMC (Gruendl+, 2009)
J/ApJ/703/736 : Clump properties in the LMC 30 Dor region (Pineda+, 2009)
J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)
J/ApJ/686/948 : CO in extragalactic giant molecular clouds (Bolatto+, 2008)
J/ApJS/178/56 : CO observations of LMC Giant Molecular clouds (Fukui+, 2008)
J/AJ/136/18 : LMC SAGE. New candidate YSOs (Whitney+, 2008)
J/A+A/471/103 : SIMBA observations of SMC (Bot+, 2007)
J/ApJ/551/852 : FCRAO CO survey of the outer Galaxy (Heyer+, 2001)
J/PASJ/53/971 : CO catalog of LMC molecular clouds (Mizuno+, 2001)
J/A+A/341/98 : The ionizing cluster of 30 Doradus. I. (Selman+ 1999)
J/A+AS/120/77 : Radio continuum study of the MC (Filipovic+, 1996)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/103] Running sequence number
5 I1 h RAh [5] Hour of right ascension (J2000)
7- 8 I2 min RAm [38] Minute of right ascension (J2000)
10- 14 F5.2 s RAs [40/55] Second of right ascension (J2000)
16 A1 --- DE- [-] Sign of declination (J2000)
17- 18 I2 deg DEd [69] Degree of declination (J2000)
20- 21 I2 arcmin DEm [4/5] Arcminute of declination (J2000)
23- 26 F4.1 arcsec DEs Arcsecond of declination (J2000)
28- 32 F5.1 km/s Vel [234.5/264.5] CO velocity
34- 37 F4.2 pc Rad [0.07/0.7] Radius
39- 42 F4.2 pc e_Rad [0.01/0.2] Rad uncertainty
44- 47 F4.2 km/s sigma [0.4/3.2] Velocity dispersion (σv)
49- 52 F4.2 km/s e_sigma [0/0.9] sigma uncertainty
54- 57 F4.1 K 13COpk [0.6/24] 13CO(2-1) brightness temperature
59- 62 F4.1 K.km/s.pc2 F13CO [0.2/86.1] 13CO(2-1) flux
64- 66 F3.1 K.km/s.pc2 e_F13CO [0.1/2] F13CO uncertainty
68- 71 F4.1 K 12COpk [2.1/62] 12CO(2-1) brightness temperature
73- 77 F5.1 K.km/s.pc2 F12CO [0.5/410] 12CO(2-1) flux
79- 81 F3.1 K.km/s.pc2 e_F12CO [0/0.8] F12CO uncertainty
83- 86 I4 Msun Mmol [14/8528] Molecular mass
88- 90 I3 Msun e_Mmol [4/167] Mmol uncertainty
92- 95 I4 Msun Mvir [21/4262] Virial mass
97-100 I4 Msun e_Mvir [7/1816] Mvir uncertainty
102-126 A25 --- Comm Comment
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 02-Mar-2015