J/A+A/651/A36 Probing the ISF in Orion A with ArTeMiS (Schuller+, 2021)
Probing the structure of a massive filament:
ArTeMiS 350 and 450 um mapping of the integral-shaped filament in Orion A.
Schuller F., Andre P., Shimajiri Y., Zavagno A., Peretto N., Arzoumanian D.,
Csengeri T., Koenyves V., Palmeirim P., Pezzuto S., Rigby A., Roussel H.,
Ajeddig H., Dumaye L., Gallais P., Le Pennec J., Martignac J., Mattern M.,
Reveret V., Rodriguez L., Talvard M.
<Astron. Astrophys. 651, A36 (2021)>
=2021A&A...651A..36S 2021A&A...651A..36S (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Molecular clouds
Keywords: stars: formation - stars: massive - ISM: structure -
submillimeter: ISM - ISM: individual objects: Orion A
Abstract:
The Orion molecular cloud is the closest region of high-mass star
formation. It is an ideal target for investigating the detailed
structure of massive star-forming filaments at high resolution and the
relevance of the filament paradigm for the earliest stages of
intermediate- to high-mass star formation. Within the Orion A
molecular cloud, the integral-shaped filament (ISF) is a prominent,
degree-long structure of dense gas and dust with clear signs of recent
and ongoing high-mass star formation. Our aim is to characterise the
structure of this massive filament at moderately high angular
resolution (8" or ∼0.016pc) in order to measure the intrinsic width
of the main filament, down to scales well below 0.1pc, which has been
identified as the characteristic width of filaments. We used the
ArTeMiS bolometer camera at APEX to map a ∼0.6x0.2deg2 region
covering OMC-1, OMC-2, and OMC-3 at 350 and 450um. We combined these
data with Herschel- SPIRE maps to recover extended emission. The
combined Herschel-ArTeMiS maps provide details on the distribution of
dense cold material, with a high spatial dynamic range, from our 8"
resolution up to the transverse angular size of the map, ∼10-15'. By
combining Herschel and ArTeMiS data at 160, 250, 350, and 450um, we
constructed high-resolution temperature and H2 column density maps.
We extracted radial intensity profiles from the column density map in
several representative portions of the ISF, which we fitted with
Gaussian and Plummer models to derive their intrinsic widths. We also
compared the distribution of material traced by ArTeMiS with that seen
in the higher-density tracer N2H+(1-0) that was recently observed
with the ALMA interferometer. All the radial profiles that we
extracted show a clear deviation from a Gaussian, with evidence for an
inner plateau that had not previously been seen clearly using
Herschel-only data. We measure intrinsic half-power widths in the
range 0.06 to 0.11pc. This is significantly larger than the Gaussian
widths measured for fibres seen in N2H+, which probably only
traces the dense innermost regions of the large-scale filament. These
half-power widths are within a factor of two of the value of ∼0.1 pc
found for a large sample of nearby filaments in various low-mass
star-forming regions, which tends to indicate that the physical
conditions governing the fragmentation of pre-stellar cores within
transcritical or supercritical filaments are the same over a large
range of masses per unit length.
Description:
The high-resolution temperature and H2 column density maps that we
constructed from the combined ArTeMiS + Herschel data are made
available. The resolution of the temperature map is limited by that of
the Herschel-SPIRE 250um data (18.2arcsec). The column density map
has a resolution of 8arcsec.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 139 2 List of fits maps
fits/* . 2 Individual fits maps
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See also:
J/A+A/600/A141 : Orion A integral shaped filament image (Kainulainen+, 2017)
J/A+A/610/A77 : Orion Integral Filament ALMA+IRAM30m N2H+(1-0) data
(Hacar+, 2018)
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- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 34 I5 Kibyte size Size of FITS file
36- 65 A30 --- FileName Name of FITS file, in subdirectory fits
67-139 A73 --- Title Title of the FITS file
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Acknowledgements:
Frederic Schuller, fschuller(at)aip.de
(End) Patricia Vannier [CDS] 27-May-2021