J/A+A/594/A58 Hi-GAL l=224deg region CO(1-0) data cubes (Olmi+, 2016)
The segregation of starless and protostellar clumps in the Hi-GAL l=224deg
region
Olmi L., Cunningham M., Elia D., Jones P.
<Astron. Astrophys. 594, A58 (2016)>
=2016A&A...594A..58O 2016A&A...594A..58O (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Millimetric/submm sources ; Radio lines
Keywords: stars: formation - ISM: clouds - ISM: molecules
Abstract:
Stars form in dense, dusty structures, which are embedded in larger
clumps of molecular clouds often showing a clear filamentary structure
on large scales (>1pc). The origin (e.g., turbulence or gravitational
instabilities) and evolution of these filaments, as well as their
relation to clump and core formation, are not yet fully understood. A
large sample of both starless and protostellar clumps can now be found
in the Herschel Hi-GAL (Herschel Infrared GALactic Plane Survey) key
project, which also provides striking images of the filamentary
structure of the parent molecular clouds. Recent results indicate that
populations of clumps on and off filaments may differ. One of the best
studied regions in the Hi-GAL survey can be observed toward the
l=224° field. Here, a filamentary region has been studied and it
has been found that protostellar clumps are mostly located along the
main filament, whereas starless clumps are detected off this filament
and are instead found on secondary, less prominent filaments. We want
to investigate this segregation effect and how it may affect the
clumps properties. We mapped the 12CO(1-0) line and its main three
isotopologues toward the two most prominent filaments observed toward
the l=224° field using the Mopra radio telescope, in order to set
observational constraints on the dynamics of these structures and the
associated starless and protostellar clumps. Compared to the starless
clumps, the protostellar clumps are more luminous, more turbulent and
lie in regions where the filamentary ambient gas shows larger
linewidths. We see evidence of gas flowing along the main filament,
but we do not find any signs of accretion flow from the filament onto
the Hi-GAL clumps. We analyze the radial column density profile of the
filaments and their gravitational stability. The more massive and
highly fragmented main filament appears to be thermally supercritical
and gravitationally bound, assuming that all of the non-thermal motion
is contributing thermal-like support, suggesting a later stage of
evolution compared to the secondary filament. The status and
evolutionary phase of the Hi-GAL clumps would then appear to correlate
with that of the host filament.
Description:
The files are the Mopra telescope data cubes used to produce the
channel maps shown in Appendix A. Intensity units are Ta*[K]. Data
cubes are not (baseline) reduced. Noise in the maps is not uniform.
Frequency resolution is 33.7kHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 109 4 *List of data cubes
fits/* . 4 Individual data cubes (intensity units are Ta*[K])
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Note on list.dat: resolution is 12arcsec (spatial) and 33.7kHz (frequency).
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Byte-by-byte Description of file: list.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- 22 I3 --- Nx Number of pixels along X-axis
24- 25 I2 --- Ny Number of pixels along Y-axis
27- 29 I3 --- Nz Number of pixels along Z-axis
31- 39 F9.2 m/s bVlsr Lower value of VELO-LSR interval
41- 47 F7.1 m/s BVlsr Upper value of VELO-LSR interval
49- 55 F7.4 m/s dVlsr VELO-LSR resolution
57- 66 F10.6 GHz RestFreq Rest frequency
68- 72 I5 Kibyte size Size of FITS file
74- 86 A13 --- FileName Name of FITS file, in subdirectory fits
88-109 A22 --- Title Title of the FITS file
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Acknowledgements:
Luca Olmi, olmi(at)arcetri.astro.it
(End) Patricia Vannier [CDS] 03-Aug-2016