J/A+A/608/A102 APEX CO and HI observations of Lupus I (Gaczkowski+, 2017)
Squeezed between shells? On the origin of the Lupus I molecular cloud.
II. APEX CO and GASS HI observations.
Gaczkowski B., Roccatagliata V., Flaischlen S., Kroell D., Krause M.G.H.
Burkert A., Diehl R., Fierlinger K., Ngoumou J., Preibisch T.
<Astron. Astrophys. 608, A102 (2017)>
=2017A&A...608A.102G 2017A&A...608A.102G (SIMBAD/NED BibCode)
ADC_Keywords: Carbon monoxide ; H II regions ; Infrared sources ;
Interstellar medium
Keywords: ISM: bubbles - ISM: clouds - ISM: kinematics and dynamics -
ISM: structure - ISM: molecules - radio lines: ISM
Abstract:
Lupus I cloud is found between the Upper Scorpius (USco) and Upper
Centaurus-Lupus (UCL) subgroups of the Scorpius-Centaurus OB
association, where the expanding USco HI shell appears to interact
with a bubble currently driven by the winds of the remaining B stars
of UCL. Aims. We investigate whether the Lupus I molecular could have
formed in a colliding flow, and in particular, how the kinematics of
the cloud might have been influenced by the larger scale gas dynamics.
We performed APEX 13CO(2-1)and C18O(2-1) line observations of
three distinct parts of Lupus I that provide kinematic information on
the cloud at high angular and spectral resolution. We compare those
results to the atomic hydrogen data from the GASS HI survey and our
dust emission results presented in the previous paper. Based on the
velocity information, we present a geometric model for the interaction
zone between the USco shell and the UCL wind bubble.
We present evidence that the molecular gas of Lupus Iis tightly linked
to the atomic material of the USco shell. The CO emission in Lupus Iis
found mainly at velocities between vLSR=3-6km/s, which is in
the same range as the HI velocities. Thus, the molecular cloud is
co-moving with the expanding USco atomic HI shell. The gas in the
cloud shows a complex kinematic structure with several line-of-sight
components that overlay each other. The nonthermal velocity dispersion
is in the transonic regime in all parts of the cloud and could be
injected by external compression. Our observations and the derived
geometric model agree with a scenario in which Lupus Iis located in
the interaction zone between the USco shell and the UCL wind bubble.
The kinematics observations are consistent with a scenario in which
the Lupus Icloud formed via shell instabilities. The particular
location of Lupus I between USco and UCL suggests that counterpressure
from the UCL wind bubble and pre-existing density enhancements,
perhaps left over from the gas stream that formed the stellar
subgroups, may have played a role in its formation.
Description:
The FITS files contain the data cubes corresponding to the 13CO(3-2)
and C18O(3-2) lines. They were taken using the Atacama Pathfinder
EXperiment (APEX) telescope, with an angular resolution of 30" and a
velocity resolution of 0.1km/s.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
15 40 05.35 -33 36 44.4 Cut A (center)
15 42 49.80 -34 08 37.8 Cut B (center)
15 44 57.60 -34 17 13.3 Cut C (center)
-----------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 114 6 List of FITS datacubes
fits/* . 6 Individual fits data cubes
--------------------------------------------------------------------------------
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- 21 I2 arcsec/pix Scale Scale of the image
23- 25 I3 --- Nx Number of pixels along X-axis
27- 29 I3 --- Ny Number of pixels along Y-axis
31- 34 I4 --- Nz Number of slides
36- 40 F5.1 km/s bVLSR Lower value of velocity interval
42- 46 F5.1 km/s BVLSR Upper value of velocity interval
48- 50 F3.1 km/s dVLSR Velocity resolution
52- 56 I5 Kibyte size Size of FITS file
58- 61 A4 --- Mol Molecule name
63- 92 A30 --- FileName Name of FITS file, in subdirectory fits
94-114 A21 --- Title Title of the file
--------------------------------------------------------------------------------
Acknowledgements:
Veronica Roccatagliata, roccatagliata(at)arcetri.astro.it
References:
Gaczkowski et al., Paper I 2015A&A...584A..36G 2015A&A...584A..36G
(End) Patricia Vannier [CDS] 14-Dec-2017