J/A+A/623/A141 G345.5+1.5 region multiwavelength study (Figueira+, 2019)
Multiwavelength study of the G345.5+1.5 region.
Figueira M., Lopez-Calderon C., Bronfman L., Zavagno A., Hervias-Caimapo C.,
Duronea N., Nyman L-A.
<Astron. Astrophys. 623, A141 (2019)>
=2019A&A...623A.141F 2019A&A...623A.141F (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Molecular clouds ; Radio lines ;
Millimetric/submm sources
Keywords: ISM: clouds - HII regions - ISM: general
Abstract:
The star formation process requires the dust and gas present in the
Milky Way to self-assemble into dense reservoirs of neutral material
where the new generation of stars will emerge. Star-forming regions
are usually studied in the context of Galactic surveys, but dedicated
observations are sometimes needed when the study reaches beyond the
survey area.
A better understanding of the star formation process in the Galaxy can
be obtained by studying several regions. This allows increasing the
sample of objects (clumps, cores, and stars) for further statistical
works and deeper follow-up studies. Here, we studied the G345.5+1.5
region, which is located slightly above the Galactic plane, to
understand its star formation properties.
We combined Large Apex BOlometer CAmera (LABOCA) and 12CO(4-3)
transition line (NANTEN2) observations complemented with the Hi-GAL
and Spitzer-GLIMPSE surveys to study the star formation toward this
region. We used the Clumpfind algorithm to extract the clumps from the
870um and 12CO(4-3) data. Radio emission at 36cm was used to
estimate the number of HII regions and to remove the contamination
from the free-free emission at 870um. We employed color-color diagrams
and spectral energy distribution (SED) slopes to distinguish between
prestellar and protostellar clumps.We studied the boundedness of the
clumps through the virial parameter. Finally, we estimated the star
formation efficiency (SFE) and star formation rate (SFR) of the region
and used the Schmidt-Kennicutt diagram to compare its ability to form
stars with other regions of the Galactic plane.
Of the 13 radio sources that we found using the MGPS-2 catalog, 7 are
found to be associated with Hii regions corresponding to late-B or
early-O stars. We found 45 870um clumps with diameters between 0.4 and
1.2pc and masses between 43M☉ and 3923M☉, and 107 12CO
clumps with diameters between 0.4 pc and 1.3pc and masses between
28M☉ and 9433M☉. More than 50% of the clumps are
protostellar and bounded and are able to host (massive) star
formation. High SFR and SFR density (S FR) values are associated with
the region, with an SFE of a few percent.
With submillimeter, CO transition, and short-wavelength infrared
observations, our study reveals a population of massive stars,
protostellar and bound starless clumps, toward G345.5+1.5. This region
is therefore actively forming stars, and its location in the starburst
quadrant of the Schmidt-Kennicutt diagram is comparable to other
star-forming regions found within the Galactic plane.
Description:
Observation of the G345.5+1.5 region obtained with APEX-LABOCA at
870um and with NANTEN-2 for the 12CO(4-3) transition line.
Physical parameters of the clumps extracted from APEX LABOCA 870um
(45 clumps, Clumpfind), Herschel Hi-GAL (79 clumps, CUTEX) and NANTEN2
12CO(4-3) (95 clumps, Clumpfind)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 61 45 Physical parameters of the 870um clumps
tablea2.dat 71 79 Physical parameters of the Hi-GAL clumps
tablea3.dat 34 95 Physical parameters of the 12CO clumps
list.dat 129 2 List of fits images
fits/* . 2 Individual fits images
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See also:
J/A+A/534/A131 : Clumps in the giant molecular cloud G345.5+1.0 (Lopez+, 2011)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Id [1/45] Clump Indentification number
5- 11 F7.3 deg GLON Galactic longitude
14- 18 F5.3 deg GLAT Galactic latitude
21- 23 F3.1 pc Diam Diameter
27- 31 F5.1 Jy Flux Integrated flux at 870um
34- 35 I2 % FFCont Percentage of contamination by
free-free emission
38- 41 I4 Msun Mass Mass of the clump
44- 50 E7.2 cm-2 ColDens Column Density of the clump
53- 58 E6.2 cm-3 VolDens Volume Density of the clump
61 A1 --- IR [Y/N] Presence (Y) or absence (N) of
IR counterparts for the clump
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Id [1/79] Clump Indentification number
5- 11 F7.3 deg GLON Galactic longitude
14- 18 F5.3 deg GLAT Galactic latitude
21- 24 F4.1 K Temp Temperature of the clump
27- 29 F3.1 K e_Temp Uncertainty on the temperature
32- 34 I3 Msun Mass Mass of the clump
37- 39 I3 Msun e_Mass Mass of the clump
42- 45 I4 Lsun Lbol Bolometric luminosity
48- 51 I4 Lsun e_Lbol Uncertainty of the bolometric luminosity
54- 57 F4.1 % LRatio Submillimetric to bolometric luminosity ratio
60- 71 A12 --- IR Nature of the source (Prestellar or Protostellar)
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Id [1/95] Clump Indentification number
5- 11 F7.3 deg GLON Galactic longitude
14- 18 F5.3 deg GLAT Galactic latitude
21- 23 F3.1 pc Diam Diameter
26- 29 I4 Msun Mass Mass of the clump
32- 34 F3.1 km/s LineW Line width of the clump
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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- 24 I4 --- Nx Number of pixels along X-axis
26- 28 I3 --- Ny Number of pixels along Y-axis
30- 32 I3 --- Nz ? Number of slices, for the datacube
34- 38 F5.1 km/s bVRAD ? Lower value of VRAD interval,
for the datacube
40- 43 F4.1 km/s BVRAD ? Upper value of VRAD interval,
for the datacube
45- 47 F3.1 km/s dVRAD ? VRAD resolution, for the datacube
49- 53 I5 Kibyte size Size of FITS file
55- 81 A27 --- FileName Name of FITS file, in subdirectory fits
83-129 A47 --- Title Title of the FITS file
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Acknowledgements:
Miguel Figueira, Miguel.Figueira(at)ncbj.gov.pl
(End) Miguel Figueira [NCBJ], Patricia Vannier [CDS] 01-Feb-2019