J/MNRAS/473/2222 1.1mm dust continuum emission along Gal. plane (Heyer+, 2018)
Early science with the large millimetre telescope:
fragmentation of molecular clumps in the galaxy.
Heyer M., Wilson G.W., Gutermuth R., Lizano S., Gomez-Ruiz A., Kurtz S.,
Luna A., Serrano Bernal E.O., Schloerb F.P.
<Mon. Not. R. Astron. Soc., 473, 2222-2233 (2018)>
=2018MNRAS.473.2222H 2018MNRAS.473.2222H (SIMBAD/NED BibCode)
ADC_Keywords: Galactic plane ; Interstellar medium ; Millimetric/submm sources ;
Molecular clouds
Keywords: stars: formation - ISM: clouds - ISM: molecules - ISM: structure -
submillimetre: ISM
Abstract:
Sensitive, imaging observations of the λ1.1mm dust continuum
emission from a 1deg2 area collected with the AzTEC bolometer
camera on the Large Millimeter Telescope are presented. A catalogue of
1545 compact sources is constructed based on a Wiener-optimization
filter. These sources are linked to larger clump structures identified
in the Bolocam Galactic Plane Survey. Hydrogen column densities are
calculated for all sources and mass and mean volume densities are
derived for the subset of sources for which kinematic distances can be
assigned. The AzTEC sources are localized, high-density peaks within
the massive clumps of molecular clouds and comprise
5-15 per cent of the clump mass. We examine the role of the
gravitational instability in generating these fragments by comparing
the mass of embedded AzTEC sources to the Jeans mass of the parent
BGPS object. For sources with distances less than 6kpc the fragment
masses are comparable to the clump Jeans mass, despite having
isothermal Mach numbers between 1.6 and 7.2. AzTEC sources linked to
ultra compact HII regions have mass surface densities greater than
the critical value implied by the mass-size relationship of infrared
dark clouds with high-mass star formation, while AzTEC sources
associated with Class II methanol masers have mass surface densities
greater than 0.7gcm-2 that approaches the proposed threshold
required to form massive stars.
Description:
Sensitive, imaging observations with 8.5arcsec angular resolution of
the 1.1mm dust continuum emission along the Galactic plane have been
used to examine the properties of high-density fragments and
subfragments within molecular clouds. The identified objects are
embedded within larger clumps of molecular clouds as measured by the
BGPS.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 78 1545 Identified AzTEC sources
table2.dat 42 632 AzTEC Sources linked to BGPS objects
table3.dat 36 1545 AzTEC 13CO velocities and dust column densities
table4.dat 55 437 AzTEC masses and mean volume densities
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See also:
J/ApJ/799/29 : BGPS. XII. DR2 distance catalog (Ellsworth-Bowers+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- AzTEC AzTEC ID
5- 24 A20 --- Name Source name, LMT_LLL.lll+BBB.bbb
27- 33 F7.4 deg GLON Source position Galactic longitude
36- 42 F7.4 deg GLAT Source position Galactic latitude
44- 51 F8.4 deg RAdeg Source position Right Ascension (J2000)
54- 60 F7.4 deg DEdeg Source position Declination (J2000)
62- 66 F5.3 Jy S1.1mm 1.1mm Flux density
68- 72 F5.3 Jy e_S1.1mm 1.1mm flux density uncertainty
74- 78 F5.2 [-] logPJ Logarithm of Joint probability that source
is a false detection
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- AzTEC AzTEC ID
6- 9 I4 --- BGPS BGPS V2.1 Catalog Number, [ERG2015] NNNN in Simbad
12- 17 F6.1 km/s VLSR ?=-999 Dense gas velocity (km/s)
19- 24 F6.1 kpc Dist ?=-999 Distance to source (kpc)
26- 31 F6.1 kpc e_Dist ?=-999 Negative tail 1 sigma distance uncertainty
33- 38 F6.1 kpc E_Dist ?=-999 Positive tail 1 sigma distance uncertainty
40 A1 --- Kdar [FNTU] Kinematic distance ambiguity resolution
flag (1)
42 I1 --- Ref [0/5] Citation or method to distance estimate (2)
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Note (1): Kinematic distance ambiguity resolution flag as follows:
F = far
N = near
T = tangent
U = unknown
Note (2): Reference as follows:
0 = unknown
1 = Ellsworth et al. (2015ApJ...799...29E 2015ApJ...799...29E, Cat. J/ApJ/799/29
2015ApJ...805..157E 2015ApJ...805..157E, Cat. J/ApJ/805/157)
2 = Svoboda et al. (2016ApJ...822...59S 2016ApJ...822...59S, Cat. J/ApJ/822/59)
3 = proximity to BGPS source with known distance
4 = Roman-Duval et al. (2010ApJ...723..492R 2010ApJ...723..492R. Cat. J/ApJ/723/492)
5 = other
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- AzTEC AzTEC ID
8- 12 F5.1 km/s V13CO 13CO velocity
14- 17 F4.1 --- Cv Contrast value = ratio of antenna temperatures
at the peak 13CO intensity to second
brightest peak
19- 24 F6.2 10+22cm-2 NH Hydrogen column density
26- 30 F5.2 10+22cm-2 e_NH Negative tail 1 sigma uncertainty of
hydrogen column density
32- 36 F5.2 10+22cm-2 E_NH Positive tail 1 sigma uncertainty of
hydrogen column density
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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2- 5 I4 --- AzTEC AzTEC ID
8- 13 F6.1 Msun Mass Mass
16- 20 F5.1 Msun e_Mass Negative tail 1 sigma uncertainty of mass
23- 27 F5.1 Msun E_Mass Postive tail 1 sigma uncertainty of mass
29- 37 F9.1 cm-3 n Mean volume density
39- 46 F8.1 cm-3 e_n Negative tail 1 sigma uncertainty of
Mean volume density
48- 55 F8.1 cm-3 E_n Postive tail 1 sigma uncertainty of
Mean volume density
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 21-Nov-2020