J/A+A/628/A96 12CO J=3-2 datacube toward N11 (Celis Pena+, 2019)
12CO and 13CO J=3-2 observations toward N11 in the Large Magellanic Cloud.
Celis Pena M., Paron S., Rubio M., Herrera C.N., Ortega M.E.
<Astron. Astrophys. 628, A96 (2019)>
=2019A&A...628A..96C 2019A&A...628A..96C (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; H II regions ; Carbon monoxide
Keywords: galaxies: ISM - Magellanic Clouds - HII regions -
ISM: individual objects: N11
Abstract:
After 30 Doradus, N11 is the second largest and brightest nebula in
the Large Magellanic Cloud (LMC). This large nebula has several OB
associations with bright nebulae at its surroundings. N11 was
previously mapped at the lowest rotational transitions of 12CO
(J=1-0 and 2-1), and in some particular regions, pointings of the
13 CO J=1-0 and 2-1 lines were also performed. Observationsof higher
CO rotational transitions are needed to map gas with higher critical
densities, which are useful to study the physical conditions of the
gas component and its relation with the UV radiation more accurately.
Using the Atacama Submillimeter Telescope Experiment, we mapped the
whole extension of the N11 nebula in the 12CO J=3-2 line and three
subregions in the 13CO J=3-2 line. The regions mapped in the
13CO J=3-2 were selected with the criterion that they were to be
exposed to the radiation in different ways: a region lying across the
nebula, which is related to the OB association LH10 (N11B), another
region that it is associated with the southern part of the nebula,
which is related to the OB association LH13 (N11D), and finally an
area farther away in the southwest without any embedded OB association
(N11I)
We found that the morphology of the molecular clouds lying in each
region shows some signatures that could be explained by the expansion
of the nebulae and the action of the radiation. Fragmentation
generated in a molecular shell due to the expansion of the N11 nebula
is suggested. The integrated line ratios 12CO/13CO show evidence
of selective photodissociation of the 13CO, and probably other
mechanisms such as chemical fractionation. The values found for the
integrated line ratios 12CO J=3-2/1-0 are in agreement with values
that were assumed in previous works, and the CO contribution to the
continuum at 870um was derived directly. The distribution of the
integrated line ratios 12CO J=3-2/2-1 show indications of stellar
feedback in N11B and N11D. The ratio between the virial and local
thermal equilibrium (LTE) mass (Mvir/MLTE) is higher than unity in
all analyzed molecular clumps, which suggests that the clumps are not
gravitationally bounded and may be supported by external pressure. A
non-LTE analysis suggests that we map gas with densities of about a
few 103cm-3. The molecular clump at N11B, the unique molecular
feature with direct evidence of ongoing star formation, is the densest
of the clumps we analyzed.
Description:
The observations of the 12 CO J=3-2 emission line that mapped the
entire N11 region were performed during November and December 2014
with the 10m Atacama Submillimeter Telescope Experiment(ASTE).
Objects:
-------------------------------------------
RA (2000) DE Designation(s)
-------------------------------------------
04 56 51.4 -66 24 24 N11 = LHA 120-N 11
-------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 111 1 Information of fits datacube
fits/* . 1 fits datacube
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 30 I3 --- Nz Number of slices
32- 41 A10 "date" Obs.date Observation date
43- 48 I6 m/s bVELO-LSR Lower value of VELO_LSR interval
50- 55 I6 m/s BVELO-LSR Upper value of VELO_LSR interval
57- 59 I3 m/s dVELO-LSR VELO_LSR resolution
61- 65 I5 Kibyte size Size of FITS file
67- 77 A11 --- FileName Name of FITS file, in subdirectory fits
79-111 A33 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Mariela Celis Pena, mariela.celis.p(at)gmail.com
(End) Patricia Vannier [CDS] 09-Aug-2019