J/A+A/499/175 12CO(2-1) map of NGC 2264-C (Maury+, 2009)
Probing the role of protostellar feedback in clustered star formation.
Mapping outflows in the collapsing protocluster NGC 2264-C.
Maury A. J., Andre P., Li Z.-Y.
<Astron. Astrophys. 499, 175 (2009)>
=2009A&A...499..175M 2009A&A...499..175M
ADC_Keywords: Associations, stellar ; Millimetric/submm sources ; Radio lines
Keywords: stars: formation : circumstellar matter -
ISM : individual objects : NGC 2264-C -
ISM : kinematics and dynamics - ISM : outflows
Abstract:
The role played by protostellar feedback in clustered star formation
is still a matter of debate. In particular, protostellar outflows have
been proposed as a source of turbulence in cluster-forming clumps,
which may provide support against global collapse for several
free-fall times. Here, we seek to test the above hypothesis in the
case of the well-documented NGC 2264-C protocluster, by quantifying
the amount of turbulence and support injected in the surrounding
medium by protostellar outflows.
Using the HERA heterodyne array on the IRAM 30m telescope, we carried
out an extensive mapping of NGC 2264-C in the three molecular line
transitions 12CO(2-1), 13CO(2-1), and C18O(2-1). We found
widespread high-velocity 12 CO emission, testifying to the presence
of eleven outflow lobes, closely linked to the compact millimeter
continuum sources previously detected in the protocluster. We carried
out a detailed analysis of the dynamical parameters of these outflows,
including a quantitative evaluation of the overall momentum flux
injected in the cluster-forming clump. These dynamical parameters were
compared to the gravitational and turbulent properties of the clump.
We show that the population of protostellar outflows identified in NGC
2264-C is likely to contribute a significant fraction of the observed
turbulence but cannot efficiently support the protocluster against
global collapse. Gravity appears to largely dominate the dynamics of
the NGC 2264-C clump at the present time ; however it is possible that
an increase in the star formation rate during the later evolution of
the protocluster will trigger enough outflows to finally halt the
contraction of the cloud.
Description:
12CO(2-1) data cube of the map obtained with the IRAM 30m telescope
towards the NGC 2264-C protocluster. The map is 6'x6' wide, and was
taken in the "on-the-fly" mode with the HERA array which allowed a 4"
sampling. The angular resolution was ∼11" and the spectral resolution
was 0.84km/s. The (0,0) of the map is located at the position of the
millimetric compact core CMM3 in NGC2264-C, which coordinates are
given in ngc2264c.dat.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
ngc2264c.dat 63 1 Information on the map
ngc2264c.fit 2880 2071 12CO(2-1) data cube FITS file
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Byte-by-byte Description of file: ngc2264c.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Name
11- 12 I2 h RAh Right ascension (J2000)
14- 15 I2 min RAm Right ascension (J2000)
17- 22 F6.3 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 35 F5.2 arcsec DEs Declination (J2000)
37- 39 F3.1 km/s LSR Mean LSR velocity of the cloud
41- 50 F10.3 GHz Freq Central frequency of the mapping
52- 63 A12 --- FileName Name of the FITS data cube file
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Acknowledgements:
Anaelle Maury, anaelle.maury(at)cea.fr
(End) Anaelle Maury [CEA-SAp, France], Patricia Vannier [CDS] 25-May-2009