J/MNRAS/500/3064 The SEDIGISM survey: First Data Release (Schuller+, 2021)
The SEDIGISM survey: First Data Release and overview of the Galactic structure.
Schuller F., Urquhart J.S., Csengeri T., Colombo D., Duarte-Cabral A.,
Mattern M., Ginsburg A., Pettitt A.R., Wyrowski F., Anderson L., Azagra F.,
Barnes P., Beltran M., Beuther H., Billington S., Bronfman L., Cesaroni R.,
Dobbs C., Eden D., Lee M.-Y., Medina S.-N.X., Menten K.M., Moore T.,
Montenegro-Montes F.M., Ragan S., Rigby A., Riener M., Russeil D.,
Schisano E., Sanchez-Monge A., Traficante A., Zavagno A., Agurto C.,
Bontemps S., Finger R., Giannetti A., Gonzalez E., Hernandez A.K.,
Henning T., Kainulainen J., Kauffmann J., Leurini S., Lopez S.,
Mac-Auliffe F., Mazumdar P., Molinari S., Motte F., Muller E.,
Nguyen-Luong Q., Parra R., Perez-Beaupuits J.-P., Schilke P., Schneider N.,
Suri S., Testi L., Torstensson K., Veena V.S., Venegas P., Wang K.,
Wienen M.
<Mon. Not. R. Astron. Soc., 500, 3064-3082 (2021)>
=2021MNRAS.500.3064S 2021MNRAS.500.3064S (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Interstellar medium ; Milky Way ; Radio lines
Keywords: surveys - ISM: structure - Galaxy: kinematics and dynamics -
radio lines: ISM
Abstract:
The SEDIGISM (Structure, Excitation and Dynamics of the Inner Galactic
Interstellar Medium) survey used the APEX telescope to map 84deg2 of
the Galactic plane between l=-60° and +31° in several
molecular transitions, including 13CO(2-1) and C18O(2-1), thus
probing the moderately dense (∼103cm-3) component of the
interstellar medium. With an angular resolution of 30arcsec and a
typical 1σ sensitivity of 0.8-1.0K at 0.25km/s velocity
resolution, it gives access to a wide range of structures, from
individual star-forming clumps to giant molecular clouds and
complexes. The coverage includes a good fraction of the first and
fourth Galactic quadrants, allowing us to constrain the large-scale
distribution of cold molecular gas in the inner Galaxy. In this paper,
we provide an updated overview of the full survey and the data
reduction procedures used. We also assess the quality of these data
and describe the data products that are being made publicly available
as part of this First Data Release (DR1). We present integrated maps
and position-velocity maps of the molecular gas and use these to
investigate the correlation between the molecular gas and the
large-scale structural features of the Milky Way such as the spiral
arms, Galactic bar and Galactic Centre. We find that approximately 60
per cent of the molecular gas is associated with the spiral arms and
these appear as strong intensity peaks in the derived Galactocentric
distribution. We also find strong peaks in intensity at specific
longitudes that correspond to the Galactic Centre and well-known
star-forming complexes, revealing that the 13CO emission is
concentrated in a small number of complexes rather than evenly
distributed along spiral arms.
Description:
Observations were done with the 12-m diameter Atacama Pathfinder
Experiment telescope (APEX; Gusten et al. 2006A&A...454L..13G 2006A&A...454L..13G),
located at 5100-m altitude on Llano de Chajnantor, in Chile. The
observational setup and observing strategy have been described in
Schuller et al. (2017A&A...601A.124S 2017A&A...601A.124S, Cat. J/A+A/601/A124)
(Paper I).
The prime target lines are 13CO(2-1) and C18O(2-1) but the 4-GHz
instantaneous bandwidth also includes a number of transitions from
other species (H2CO, CH3OH, SO, SO2, HNCO, HC3N, SiO). The
observations have been carried out in tiles of 0.25°x0.50°
using position switching in the on-the-fly mapping mode. Each position
in the survey is covered by at least two maps observed in orthogonal
scanning directions, along galactic longitude and latitude. The
0.25°x0.50° tiles oriented along l or b were sometimes
observed under different conditions.
The reference positions for each field were selected to be ±1.5°
off the Galactic mid-plane to avoid contamination, and while this was
sufficient to ensure the C18O(2-1) data were clean, this was not
always the case for the brighter 13CO(2-1) transition. Therefore, we
have systematically performed pointed observations towards the
references points, using an off position further from the Galactic
plane.
The data were processed using standard procedures in GILDAS/CLASS. The
spectra were smoothed to 0.2km/s resolution. Table A1 lists the
measured rms at that resolution, and the number of lines detected and
their vlsr velocities. Only the lines detected at more than 5σ
(in integrated intensity) are listed.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 108 325 Spectra observed towards the reference
positions: measured rms and spectral lines
detected
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See also:
J/A+A/601/A124 : Clouds in SEDIGISM science demonstration field
(Schuller+, 2017)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 11 A11 --- Name Galactic coordinates of the on-source map
(LLL.ll+B.bb)
13- 17 F5.3 K sigrms Measured rms at 0.2km/s resolution
19-108 A90 --- Lines Spectral lines detected
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History:
From electronic version of the journal
References:
Schuller et al., Paper I 2017A&A...601A.124S 2017A&A...601A.124S, Cat. J/A+A/601/A124
(End) Ana Fiallos [CDS] 04-Oct-2023