J/MNRAS/453/645 Massive molecular outflows distance-limited sample (Maud+, 2015)
A distance-limited sample of massive molecular outflows.
Maud L.T., Moore T.J.T., Lumsden S.L., Mottram J.C., Urquhart J.S.,
Hoare M.G.
<Mon. Not. R. Astron. Soc., 453, 645-665 (2015)>
=2015MNRAS.453..645M 2015MNRAS.453..645M (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; H II regions; Carbon monoxide
Keywords: stars: abundances - stars: formation - stars: massive -
stars: protostars - stars: winds, outflows
Abstract:
We have observed 99 mid-infrared-bright, massive young stellar objects
and compact HII regions drawn from the Red MSX source survey in the
J=3-2 transition of 12CO and 13CO, using the James Clerk
Maxwell Telescope. 89 targets are within 6kpc of the Sun, covering a
representative range of luminosities and core masses. These constitute
a relatively unbiased sample of bipolar molecular outflows associated
with massive star formation. Of these, 59, 17 and 13 sources (66, 19
and 15 percent) are found to have outflows, show some evidence of
outflow, and have no evidence of outflow, respectively. The
time-dependent parameters of the high-velocity molecular flows are
calculated using a spatially variable dynamic time-scale. The
canonical correlations between the outflow parameters and source
luminosity are recovered and shown to scale with those of low-mass
sources. For coeval star formation, we find the scaling is consistent
with all the protostars in an embedded cluster providing the outflow
force, with massive stars up to ∼30M☉ generating outflows.
Taken at face value, the results support the model of a scaled-up
version of the accretion-related outflow-generation mechanism
associated with discs and jets in low-mass objects with time-averaged
accretion rates of ∼ 10-3M☉/yr on to the cores. However, we
also suggest an alternative model, in which the molecular outflow
dynamics are dominated by the entrained mass and are unrelated to the
details of the acceleration mechanism. We find no evidence that
outflows contribute significantly to the turbulent kinetic energy of
the surrounding dense cores.
Description:
The observations were undertaken using the JCMT in 2007 and 2008 as
part of projects 07AU08, 07BU16, 08AU19 and 08BU18. The full-width
half-maximum (FWHM) beam size at ∼345GHz for the 12CO (J=3-2)
transition is ∼14.5arcsec.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 108 99 Source parameters for all objects in the sample,
taken from the RMS survey online archive
table2.dat 77 99 Outflow-detection parameters for all objects
in the sample
table3.dat 81 77 Mass, momentum and energy calculated for all
sources (including those where D>6kpc) with
outflows or with evidence of outflows where
apertures could be defined
table4.dat 86 77 Dynamic timescale and tdyn-dependent parameters
calculated for all sources (including those
where D>6 kpc) with outflows or with evidence
of outflows, where apertures could be defined
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See also:
V/114 : MSX6C Infrared Point Source Catalog (Egan+ 2003)
J/A+A/461/11 : Radio observations of MYSO candidates (Urquhart+, 2007)
J/A+A/474/891 : 13CO observations of YSOs in South Gal. plane (Urquhart+, 2007
J/A+A/487/253 : The RMS survey: 13CO observations of YSOs (Urquhart+ 2008)
J/A+A/501/539 : RMS survey. 6cm observations of YSOs (Urquhart+, 2009)
J/ApJS/208/11 : The Red MSX Source Survey: massive protostars (Lumsden+, 2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- MSX MSX source name (GLLL.llll+BB.bbbb)
19- 20 I2 h RAh Right ascension (J2000)
22- 23 I2 min RAm Right ascension (J2000)
25- 26 I2 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 36 I2 arcsec DEs Declination (J2000)
38- 44 A7 --- Type Type of the source
47- 51 F5.1 km/s Vlsr LSR velocity
53- 56 F4.1 kpc Dist Distance
58- 63 I6 Lsun L Luminosity
65- 75 A11 --- IRAS Associated IRAS source name
77- 78 I2 arcsec Off ? Offset of IRAS source to MSX source
80-108 A29 --- ONames Other names of associated source(s)
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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- 17 A17 --- MSX MSX source name (GLLL.llll+BB.bbbb)
19 A1 --- Flow [YMN] Nature of outfolw (1)
21- 23 F3.1 K Spec.Noise Spectral noise (σTmb)
25- 29 F5.1 km/s b_Dvb1 ? Lower value of raw velocity range extend
of the blue-shifted lobe with respect
to the observed velocities
30 A1 --- --- [,]
31- 35 F5.1 km/s B_Dvb2 ? Upper value of of raw velocity range
extend of the blue-shifted lobe with
respect to the observed velocities
37- 41 F5.1 km/s b_Dvr1 ? Lower value of raw velocity range extend
of the red-shifted lobe with respect to
the observed velocities
42 A1 --- --- [,]
43- 47 F5.1 km/s B_Dvr2 ? Upper value of raw velocity range extend
of the red-shifted lobe with respect to
the observed velocities
49- 52 F4.1 K.km/s BM ? Blue-shifted map medium noise
54- 56 F3.1 K.km/s e_BM ? rms uncertainty on BM
58- 61 F4.1 K.km/s RM ? red-shifted map medium noise
63- 65 F3.1 K.km/s e_RM ? rms uncertainty on RM
67- 70 F4.1 km/s vmaxb ? Maximum velocity offset from the vLSR
for the blue-shifted lobe
72- 75 F4.1 km/s vmaxr ? Maximum velocity offset from the vLSR
for the red-shifted lobe
77 A1 --- Aper [YNS] Aperture flag (2)
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Note (1): Outflow flag as follows:
Y = source has an outflow
M = shows some evidence of an outflow (maybe)
N = no outflow at all
Note (2): Aperture flag as follows:
Y = good aperture
S = manually `selected' aperture
N = no aperture
Sources without outflows have no aperture, but also some M sources have no
aperture due to complex diffuse emission.
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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- 17 A17 --- MSX MSX Source Name
19- 23 F5.1 Msun Massb Blue-shifted lobe mass (1)
25- 29 F5.1 Msun Massr Red-shifted lobe mass (1)
31- 36 F6.1 Msun Masstot Total mass (1)
38- 43 F6.1 Msun.km/s Pb Blue-shifted lobe momentum (1)
45- 50 F6.1 Msun.km/s Pr Red-shifted lobe momentum (1)
52- 57 F6.1 Msun.km/s Ptot Total momentum (1)
59- 65 F7.1 10+35W Eb Blue-shifted lobe energy (1)
67- 73 F7.1 10+35W Er Red-shifted lobe energy (1)
75- 81 F7.1 10+35W Etot Total energy (1)
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Note (1): Uncertainties calculated from adoption a different integrated velocity
range (±0.4km/s at the upper and the lower velocity boundary) are ,36, 26
and 23 percent for mass, momentum and energy respectively.
Note, errors in source distance, and more importantly outflow inclination
angle could have a much more significant effect. Cabrit & Bertout
(1990ApJ...348..530C 1990ApJ...348..530C) suggest uncertainties up to an order of magnitude for
energy values if the outflows have large inclination angles (>70°).
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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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1- 17 A17 --- MSX MSX Source Name
19- 22 F4.1 10+4yr Tdynb Blue-shifted lobe dynamic timescale (1)
24- 27 F4.1 10+4yr Tdynr Red-shifted lobe dynamic timescale (1)
29- 32 F4.1 10+4yr Tdynave Average (of both lobes) dynamic
timescale (1)
34- 37 F4.1 10-4Msun/yr dM/dtb Blue-shifted lobe mass flow rate (1)
39- 42 F4.1 10-4Msun/yr dM/dtr Red-shifted lobe mass flow rate (1)
44- 48 F5.1 10-4Msun/yr dM/dttot Total mass flow rate (1)
50- 53 F4.1 10-3Msun.km/s/yr dP/dtb Blue-shifted lobe force (1)
55- 58 F4.1 10-3Msun.km/s/yr dP/dtr Red-shifted lobe force (1)
60- 64 F5.1 10-3Msun.km/s/yr dP/dttot Total force (1)
66- 71 F6.3 Lsun dE/dtb Blue-shifted lobe power (1)
74- 79 F6.3 Lsun dE/dtr Red-shifted lobe power (1)
81- 86 F6.3 Lsun dE/dttot Total power (1)
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Note (1): Uncertainties as in Figure 5 are 50 percent for dM/dt, dP/dt and
dE/dt, as discussed in the text, uncertainty in how t_dyn- is calculated and
also due to inclination correction can make these easily an order of magnitude.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Feb-2016