J/A+A/627/A162 L1489 starless core carbon-chain-producing region (Wu+, 2019)
A particular carbon-chain-producing region: L1489 starless core.
Wu Y., Lin L., Liu X., Chen X., Liu T., Zhang C., Ju B., Yuan J., Wang J.,
Shen Z., Kim K.-T., Qin S.-L., Li J., Liu H., Zhang T., Xu Y., Liu Q.
<Astron. Astrophys. 627, A162 (2019)>
=2019A&A...627A.162W 2019A&A...627A.162W (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Interstellar medium ; Radio lines ;
Spectroscopy
Keywords: ISM: molecules - ISM: abundances - stars: formation -
ISM: jets and outflows
Abstract:
We present the results of a study of a particular
carbon-chain-producing region, L1489 starless core (L1489 EMC), which
is located at 1-arcmin east of L1489 IRS.
We detected carbon-chain molecules (CCMs) HC2n+1N (n=1-3) and C3S
in Ku band as well as high-energy excitation lines including C4H
N=9-8, J=17/2-15/2, 19/2-17/2, and CH3CCH J=5-4, K=2 in the 3mm band
toward a starless core called the eastern molecular core (EMC) of
L1489 IRS. Maps of all the observed lines were also obtained.
Comparisons with a number of early starless cores and WCCC source
L1527 show that the column densities of C4H and CH3CCH are close
to those of L1527, and the CH3CCH column densities of the EMC and
L1527 are slightly higher than those of TMC-1. The EMC and L1527 have
similar C3S column densities, but they are much lower than those of
all the starless cores, with only 6.5% and 10% of the TMC-1 value,
respectively. The emissions of the N-bearing species of the EMC and
L1527 are at the medium level of the starless cores. These comparisons
show that the CCM emissions in the EMC are similar to those of L1527,
though L1527 contains a protostar. Although dark and quiescent, the
EMC is warmer and at a later evolutionary stage than classical
carbon-chain-producing regions in the cold, dark, quiescent early
phase. The PACS, SPIRE, and SCUBA maps evidently show that the L1489
IRS seems to be the heating source of the EMC. Although it is located
at the margins of the EMC, its bolometric luminosity and bolometric
temperature are relatively high. Above all, the EMC is a rather
particular carbon-chain-producing region and is quite significant for
CCM science.
Description:
The Ku band lines with TMRT 65m and 3mm band lines with PMO 13.7m
towards L1489 EMC are presented.
The Ku band otf cubes for transitions HC3N J=2-1, HC5N J=6-5,
HC7N J=14-13 C3S J=3-2; the 3mm band otf cubes for transitions
C4H N=9-8, J=19/2-17/2 17/2-15/2, CH3CCH J=5-4, K=0 c-HCCCH
2(1,2)-1(0,1), HC3N J=10-9.
There are also single lines towards opacity center point (O point,
J2000 04:04:47.5 +26:19:42) of the Ku transitions listed above as well
as CH3CCH J=5-4, K=1,2, HC7N J=15-14 16-15.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
04 04 47.5 +26 19 42 L1489 = LDN 1489
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 149 16 List of fits files
fits/* . 16 Individual fits files
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See also:
J/A+A/475/915 : L1489IRS observed by the submillimeter array (Brinch+, 2007)
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- 26 I2 --- Ny ? Number of pixels along Y-axis
for the datacubes
28- 30 I3 --- Nz ? Number of pixels along Z-axis
for the datacubes
32- 54 A23 "datime" Obs.date Observation date
56- 67 E12.6 m/s bVRAD Lower value of VRAD interval
69- 80 E12.6 m/s BVRAD Upper value of VRAD interval
82- 91 F10.4 m/s dVRAD VRAD resolution
93- 95 I3 Kibyte size Size of FITS file
97-108 A12 --- FileName Name of FITS file, in subdirectory fits
110-149 A40 --- Title Title of the FITS file
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Acknowledgements:
Yuefang Wu, ywu(at)pku.edu.cn
(End) Yuefang Wu [PKU, China], Patricia Vannier [CDS] 27-May-2019