J/A+A/618/A46 W3(H2O/OH) continuum & line data cubes at 1.3mm (Ahmadi+, 2018)
Core fragmentation and Toomre stability analysis of W3(H2O).
A case study of the IRAM NOEMA large program CORE.
Ahmadi A., Beuther H., Mottram J. C., Bosco F., Linz H., Henning T.,
Winters J. M., Kuiper R., Pudritz R., Sanchez-Monge A., Keto E., Beltran M.,
Bontemps S., Cesaroni R., Csengeri T., Feng S., Galvan-Madrid R.,
Johnston K. G., Klaassen P., Leurini S., Longmore S. N., Lumsden S.,
Maud L. T., Menten K. M., Moscadelli L., Motte F., Palau A., Peters T.,
Ragan S. E., Schilke P., Urquhart J. S., Wyrowski F., Zinnecker H.
<Astron. Astrophys. 618, A46 (2018)>
=2018A&A...618A..46A 2018A&A...618A..46A (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Millimetric/submm sources
Keywords: stars: formation - stars: massive - stars: early-type -
stars: kinematics and dynamics -
stars: individual: W3(H2O), W3(OH) - techniques: interferometric
Abstract:
The fragmentation mode of high-mass molecular clumps and the
properties of the central rotating structures surrounding the most
luminous objects have yet to be comprehensively characterised. We
study the fragmentation and kinematics of the high-mass star-forming
region W3(H2O), as part of the IRAM NOrthern Extended Millimeter
Array (NOEMA) large programme CORE. Using the IRAM NOEMA and the IRAM
30m telescope, the CORE survey has obtained high-resolution
observations of 20 well-known highly luminous star-forming regions in
the 1.37 mm wavelength regime in both line and dust continuum
emission. We present the spectral line set-up of the CORE survey and a
case study for W3(H2O). At ∼0.35" (700AU at 2.0kpc) resolution, the
W3(H2O) clump fragments into two cores (west and east), separated by
∼2300AU. Velocity shifts of a few km/s are observed in the
dense-gas tracer, CH3CN, across both cores, consistent with rotation
and perpendicular to the directions of two bipolar outflows, one
emanating from each core. The kinematics of the rotating structure
about W3(H2O) W shows signs of differential rotation of material,
possibly in a disk-like object. The observed rotational signature
around W3(H2O) E may be due to a disk-like object, an unresolved
binary (or multiple) system, or a combination of both. We fit the
emission of CH3CN (12K-11K) K=4-6 and derive a gas
temperature map with a median temperature of ∼165K across W3(H2O).
We create a Toomre Q map to study the stability of the rotating
structures against gravitational instability. The rotating structures
appear to be Toomre unstable close to their outer boundaries, with a
possibility of further fragmentation in the differentially rotating
core, W3(H2O) W. Rapid cooling in the Toomre unstable regions
supports the fragmentation scenario. Combining millimetre dust
continuum and spectral line data toward the famous high-mass
star-forming region W3(H2O), we identify core fragmentation on large
scales, and indications for possible disk fragmentation on smaller
spatial scales.
Description:
Interferometric observations carried out between 2014-2016 with the
NOrthern Extended Millimeter Array (NOEMA) towards the high-mass star
forming regions W3(H2O) and W3(OH). The FITS files include the
continuum emission at 1.37mm (220GHz), and data cubes of the lines
observed with the Narrowband and WideX receivers with ∼0.4km/s and
∼2.7km/s resolution, respectively. The data cube of 30-m line
observations of 13CO is also included, as well as the merged NOEMA
and 30-m observations of 13CO as presented in the paper.
Objects:
----------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------
02 27 03.87 +61 52 24.5 W3(H2O) = W3H2O
----------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
map.dat 254 14 Description of FITS files
fits/* . 14 Individual FITS files
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Byte-by-byte Description of file: map.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 F5.3 arcsec/pix Scale [0.074/5.581] Scale of the image
26- 29 I4 --- Nx [18/1024] Number of pixels along X-axis
31- 34 I4 --- Ny [18/1024] Number of pixels along Y-axis
36- 39 I4 --- Nz [30/1843]? Number of slices for datacubes
41- 48 F8.2 km/s RVmin [-1698/-48]? Lower value of radial
velocity interval for data cubes
50- 56 F7.2 km/s RVmax [-22/3215]? Upper value of radial
velocity interval for data cubes
58- 61 F4.2 km/s dRV [0.4/2.7]? Velocity resolution
63- 69 F7.3 GHz Freq [218/231]? Frequency of line observed
71- 77 I7 Kibyte size [45/75489336] Size of FITS file
79-114 A36 --- FileName Name of FITS file in subdirectory fits
116-254 A139 --- Title Title of the file
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Acknowledgements:
Aida Ahmadi, ahmadi(at)mpia.de,
Max Planck Institute for Astronomy, Germany
(End) A. Ahmadi [Max Planck Inst. for Astronomy], P. Vannier [CDS] 11-Sep-2018