J/A+A/621/A62 4 LMC SFRs velocity profile maps (Okada+, 2019)
Velocity profiles of [CII], [CI], CO, and [OI] and physical conditions in four
star-forming regions in the Large Magellanic Cloud.
Okada Y., Guesten R., Requena-Torres M.A., Roellig M., Stutzki J.,
Graf U.U., Hughes A.
<Astron. Astrophys. 621, A62 (2019)>
=2019A&A...621A..62O 2019A&A...621A..62O (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Interstellar medium ; Star Forming Region ;
Line Profiles
Keywords: ISM: lines and bands - Magellanic Clouds - photon-dominated region -
ISM: kinematics and dynamics
Abstract:
The aim of our study is to investigate the physical properties of the
star-forming interstellar medium (ISM) in the Large Magellanic Cloud
(LMC) by separating the origin of the emission lines spatially and
spectrally. The LMC provides a unique local template to bridge studies
in the Galaxy and high redshift galaxies because of its low metallicity
and proximity, enabling us to study the detailed physics of the ISM in
spatially resolved individual star-forming regions. Following Okada et al.
(2015A&A...580A..54O 2015A&A...580A..54O), we investigate different phases of the ISM traced
by carbon-bearing species in four star-forming regions in the LMC, and
model the physical properties using the KOSMA-τ PDR model.
We mapped 3-13 arcmin2 areas in 30 Dor, N158, N160, and N159 along
the molecular ridge of the LMC in [C II] 158 µm with GREAT on board
SOFIA. We also observed the same area with CO(2-1) to (6-5), 13CO(2-1)
and (3-2), [C I] 3P1-3P0 and 3P2-3P1 with APEX.
For selected positions in N159 and 30 Dor, we observed [O I] 145 µm
and [O I] 63 µm with upGREAT. All spectra are velocity resolved.
In all four star-forming regions, the line profiles of CO, 13CO, and
[C I] emission are similar, being reproduced by a combination of Gaussian
profiles defined by CO(3-2), whereas [C II] typically shows wider line
profiles or an additional velocity component. At several positions in
N159 and 30 Dor, we observed the velocity-resolved [O I] 145 and 63 µm
lines for the first time. At some positions, the [O I] line profiles
match those of CO, at other positions they are more similar to the [C II]
profiles. We interpret the different line profiles of CO, [C II] and
[O I] as contributions from spatially separated clouds and/or clouds
in different physical phases, which give different line ratios depending
on their physical properties. We modeled the emission from the CO,
[C I], [C II], and [O I] lines and the far-infrared continuum emission
using the latest KOSMA-τ PDR model, which treats the dust-related
physics consistently and computes the dust continuum SED together with
the line emission of the chemical species. We find that the line and
continuum emissions are not well-reproduced by a single clump ensemble.
Toward the CO peak at N159 W, we propose a scenario that the CO, [C II],
and [O I] 63 µm emission are weaker than expected because of mutual
shielding among clumps.
Description:
This paper presents velocity-resolved line maps of [CII], [CI], and CO
emission over 3-13 arcmin2 areas in the star-forming regions N159,
N160, 30Dor, and N158 in the Large Magellanic Cloud (LMC). They were
observed with GREAT onboard SOFIA and APEX. As used in the paper, we
provide maps with 30 arcsec resolution and 16 arcsec resolution (the
latter is only for lines with the original resolution of less than
16 arcsec).
Objects:
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RA (2000) DE Designation(s)
----------------------------------------------------
05 39 51.10 -69 45 12.9 N159 = LHA 120-N159
05 39 03.00 -69 07 36.0 30Dor = 30 Dor region
05 39 40.30 -69 39 01.1 N160 = LHA 120-N160
05 39 10.00 -69 30 20.0 NGC2074 = LHA 120-N158C
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 131 49 List of fits datacubes
fits/* . 49 Individual fits datacubes
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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- 24 F5.2 arcsec/pix scale Scale of the image
26- 27 I2 --- Nx Number of pixels along X-axis
29- 30 I2 --- Ny Number of pixels along Y-axis
32- 34 I3 --- Nz Number of slices
36- 41 I6 m/s Vlsr LSR velocity
43- 46 I4 m/s bVel Lower value of relative velocity interval
48- 50 I3 m/s BVel Upper value of relative velocity interval
52 I1 m/s dVel Velocity resolution
54- 57 I4 Kibyte size Size of FITS file
59- 82 A24 --- FileName Name of FITS file, in subdirectory fits
84-131 A48 --- Title Title of the FITS file
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Acknowledgements:
Yoko Okada, okada(at)ph1.uni-koeln.de
(End) Yoko Okada [Univ. Koeln, Germany], Patricia Vannier [CDS] 02-Oct-2018