J/ApJ/867/94 ALMA 1.3mm continuum flux measurement of C1-S core (Kong+, 2018)
Zooming in to massive star birth.
Kong S., Tan J.C., Caselli P., Fontani F., Wang K., Butler M.J.
<Astrophys. J., 867, 94 (2018)>
=2018ApJ...867...94K 2018ApJ...867...94K
ADC_Keywords: Interstellar medium; Millimetric/submm sources
Keywords: ISM: jets and outflows ; ISM: kinematics and dynamics ;
ISM: magnetic fields ; stars: formation ; stars: massive ;
stars: protostars
Abstract:
We present high-resolution (0.2", 1000au) 1.3mm ALMA observations of
the massive infrared dark cloud clump, G028.37+00.07-C1, thought to
harbor the early stages of massive star formation. Using N2D+(3-2),
we resolve the previously identified C1-S core, separating the bulk of
its emission from two nearby protostellar sources. C1-S is thus
identified as a massive (∼50M☉), compact (∼0.1pc diameter)
starless core, e.g., with no signs of outflow activity. Being highly
deuterated, this is a promising candidate for a pre-stellar core on
the verge of collapse. An analysis of its dynamical state indicates a
sub-virial velocity dispersion compared to a trans-Alfvenic turbulent
core model. However, virial equilibrium could be achieved with sub-
Alfvenic conditions involving magnetic field strengths of ∼2mG.
Description:
The observations were carried out during ALMA Cycle 2, under the
project 2013.1.00248.S (PI: Tan) using two configurations of the 12m
array. The observation in the compact configuration (C34-1) was
performed on 2015 April 5 (UTC) with 34 12m antennas and a total
on-source integration time of 2087s. The angular resolution obtained
from this observation is about 1.5".
The data in the extended configuration (C34-6) were taken on 2015 July
3 (UTC) with 43 12m antennas and a total on-source integration time of
4174s. The angular resolution obtained from this observation is about
0.25".
Both observations targeted RAJ2000=18:42:46.585634,DEJ2000=-04:04:12.36111,
which is in between C1-N and C1-S. The observations were carried out
in ALMA band 6.
The Karl G. Jansky Very Large Array (VLA) of NRAO was pointed toward
C1-S in its D configuration on 2014 August 12 and September 11, with
the same correlator setup to observe NH3(J,K)=(1,1) and (2,2) lines.
Objects:
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RA (ICRS) DE Designation(s)
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18 42 46.50 -04 04 16.0 C1-S = [TKB2013] C1-S
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 41 15 Continuum flux measurement data for Figures 4 and 5
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See also:
J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)
J/ApJ/641/389 : Millimetric observations of IRDC cores (Rathborne+, 2006)
J/ApJS/175/509 : Ammonia spectral atlas in Perseus (Rosolowsky+, 2008)
J/A+A/570/A51 : Molecular lines in 4 IRCS clumps (Shipman+, 2014)
J/A+A/592/A21 : Are infrared dark clouds really quiescent? (Feng+, 2016)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 AU RC1-sa [588/4193]? Projected radius for C1-Sa annuli
6- 9 I4 MJy/sr FC1-sa [231/2266]? C1-Sa annulus 1.3mm continuum flux
density
11- 12 I2 MJy/sr e_FC1-sa [10/25]? Uncertainty in FC1-Sa
14- 19 F6.1 AU RC1-So [554/8954] Projected radius for C1-S outer annuli
21- 25 F5.1 MJy/sr FC1-So [79/152] C1-S outer annulus 1.3mm continuum
flux density
27- 30 F4.1 MJy/sr e_FC1-So [7/27] Uncertainty in FC1-So
32- 36 F5.1 MJy/sr FC1-Sos [46/118] C1-S outer with envelope subtraction
annulus 1.3 mm continuum flux density
38- 41 F4.1 MJy/sr e_FC1-Sos [25/37] Uncertainty in FC1-Sos
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Oct-2019