J/A+A/581/A71 Orion-KL substructure at 1.3mm (Feng+, 2015)
Resolving the chemical substructure of Orion-KL.
Feng S., Beuther H., Henning T., Semenov D., Palau A., Mills E.A.C.
<Astron. Astrophys. 581, A71 (2015)>
=2015A&A...581A..71F 2015A&A...581A..71F
ADC_Keywords: Radio continuum ; Radio lines ; Abundances
Keywords: stars: formation - ISM: abundance - stars: massive -
ISM: lines and bands - ISM: molecules - submillimeter: ISM
Abstract:
The Kleinmann-Low nebula in Orion (Orion-KL) is the nearest example of
a high-mass star-forming environment. For the first time, we
complemented 1.3mm Submillimeter Array (SMA) interferometric line
survey with IRAM 30m single-dish observations of the Orion-KL region.
Covering a 4GHz bandwidth in total, this survey contains over 160
emission lines from 20 species (25 isotopologues), including 10
complex organic molecules (COMs).
At a spatial resolution of 1200AU, the continuum substructures are
resolved. Extracting the spectra from individual substructures and
providing the intensity-integrated distribution map for each species,
we studied the small-scale chemical variations in this region.
Our main results are: (1) We identify lines from the low-abundance
COMs CH3COCH3 and CH3CH2OH, as well as tentatively detect CH3CHO and
long carbon-chains C6H and HC7N. (2) We find that while most COMs are
segregated by type, peaking either towards the hot core (e.g.,
N-bearing species) or the compact ridge (e.g., O-bearing species like
HCOOCH3, CH3OCH3, the distributions of others do not follow this
segregated structure (e.g., CH3CH2OH, CH3OH, CH3COCH3). (3) We find a
second velocity component of HNCO, 34SO2, and SO lines, which may be
associated with a strong shock event in the low-velocity outflow. (4)
Temperatures and molecular abundances show large gradients between
central condensations and the outflow regions, illustrating a
transition between hot molecular core and shock-chemistry dominated
regimes.
Our observations of spatially resolved chemical variations in Orion-KL
provide the nearest reference source for hot molecular core and
outflow chemistry, which will be an important example for interpreting
the chemistry of more distant HMSFRs.
Description:
At an angular resolution of 3", 8 substructures are resolved in
Orion-KL from the 1.3 mm continuum map. From the
interferometric-single dish (SMA+30m) complemented data, more than 160
emission lines from 20 species (25 isotopologues) are identified. We
imaged the spatial distribution for all the identified lines from the
SMA+30m complemented data and provided the datacube (with a spectral
resolution of 1.2km/s).
Objects:
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RA (2000) DE Designation(s)
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05 35 14.16 -05 22 21.5 Orion-KL = NAME ORION-KL
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 220 3 List of fits files
fits/* . 3 Individual fits files
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See also:
J/ApJS/156/127 : 350µm molecular line survey of Orion KL (Comito+, 2005)
J/A+A/532/A32 : HCOOCH3 map of Orion-KL (Favre+, 2011)
J/A+A/559/A51 : HC3N in Orion KL (Esplugues+, 2013)
J/ApJ/769/48 : Water maser in Orion-KL with Herschel (Neufeld+, 2013)
J/ApJ/777/120 : cm to submm spectra of H2C=CH-CH2NC (Haykal+, 2013)
J/A+A/568/A65 : NGC 7129 FIRS 2 interferometric 1-D spectrum (Fuente+, 2014)
J/A+A/572/A44 : Vibrationally excited vinyl cyanide in Orion-KL (Lopez+, 2014)
J/ApJ/779/119 : HCOOCH2D detection in Orion KL (Coudert+, 2013)
J/ApJS/215/25 : Methyl formate (HCOOCH3) observations (Favre+, 2014)
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 image center (J2000)
10- 18 F9.5 deg DEdeg Declination of image center (J2000)
20- 22 F3.1 arcsec/pix Scale [0.4] Scale of the image
24- 26 I3 --- Nx [256] Number of pixel along X-axis
28- 30 I3 --- Ny [256] Number of pixel along Y-axis
32- 35 I4 --- Nz [2300/2600]? Number of slices for data cubes
37- 55 A19 "datime" Date Observation date (YYYY-MM-DDThh:mm:ss.s)
59- 66 F8.2 km/s V.min Lower value of LSR velocity for datacubes
or LSR velocity for image
70- 76 F7.1 km/s V.max ? Upper value of LSR velocity for datacubes
82- 85 F4.2 km/s dV [1.2]? Velocity resolution for datacubes
87- 92 I6 Kibyte size Size of FITS file
94-118 A25 --- FileName Name of the fits file in subdirectory fits
120-220 A101 --- Title Title of the file
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Acknowledgements:
Siyi Feng, syfeng(at)mpia.de and syfeng(at)mpe.mpg.de
(End) Siyi Feng [MPE, Germany], Patricia Vannier [CDS] 20-May-2015