J/A+A/627/A27 M16 CO maps (Xu+, 2019)
The effects of ionization feedback on star formation:
A case study of the M16 H II region.
Xu J.-L., Zavagno A., Yu N., Liu X.-L., Xu Y., Yuan J., Zhang C.-P.,
Zhang S.-J., Zhang G.-Y., Ning C.-C., Ju B.-G.
<Astron. Astrophys. 627, A27 (2019)>
=2019A&A...627A..27X 2019A&A...627A..27X (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Carbon monoxide
Keywords: H II regions - ISM: clouds - stars: formation -
Abstract:
We aim to investigate the impact of the ionized radiation from the M16
HII region on the surrounding molecular cloud and on its hosted star
formation.
To present comprehensive multi-wavelength observations towards the M16
HII region, we used new CO data and existing infrared, optical, and
submillimeter data. The 12CO J=1-0, 13CO J=1-0, and C18O J=1-0
data were obtained with the Purple Mountain Observatory (PMO) 13.7m
radio telescope. To trace massive clumps and extract young stellar
objects (YSOs) associated with the M16 HII region, we used the
ATLASGAL and GLIMPSE I catalogs, respectively.
From CO data, we discern a large-scale filament with three velocity
components. Because these three components overlap with each other in
both velocity and space, the filament may be made of three layers. The
M16 ionized gas interacts with the largescale filament and has
reshaped its structure. In the large-scale filament, we find 51
compact cores from the ATLASGAL catalog, 20 of them being quiescent.
The mean excitation temperature of these cores is 22.5K, while this
is 22.2K for the quiescent cores. This high temperature observed for
the quiescent cores suggests that the cores may be heated by M16 and
do not experience internal heating from sources in the cores. Through
the relationship between the mass and radius of these cores, we obtain
that 45% of all the cores are massive enough to potentially form
massive stars. Compared with the thermal motion, the turbulence
created by the nonthermal motion is responsible for the core
formation. For the pillars observed towards M16, the H II region may
give rise to the strong turbulence.
Description:
CO data are observed by using the PMO 13.7m radio telescope.
We map a 45'x45' region centered at l=17.023°, b=0.871° in the
transitions of 12CO J=1-0 (115.271GHz), 13CO J=1-0 (110.201GHz),
and C18O J=1-0 (109.782GHz) lines.
Objects:
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RA (2000) DE Designation(s)
-----------------------------------------
18 18 48 -13 48.4 M16 = NGC 6611
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 87 3 List of fits maps
fits/* . 3 Individual fits maps
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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 A1 --- --- [G]
2- 10 F9.5 deg GLON Galactic longitude of center (J2000)
11- 19 F9.5 deg GLAT Galactic latitude of center (J2000)
21- 22 I2 --- Nx Number of pixels along X-axis
24- 25 I2 --- Ny Number of pixels along Y-axis
27- 29 I3 --- Nz Number of slices
31- 38 F8.1 m/s bVRAD Lower value of VRAD interval
40- 46 F7.1 m/s BVRAD Upper value of VRAD interval
48- 54 F7.3 m/s dVRAD VRAD resolution
56- 59 I4 Kibyte size Size of FITS file
61- 72 A12 --- FileName Name of FITS file, in subdirectory fits
74- 87 A14 --- Title Title of the FITS file
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Acknowledgements:
Jin-Long Xu, xujl(at)bao.ac.cn
(End) Patricia Vannier [CDS] 06-Jun-2019