J/A+A/586/A149 SiO in ATLASGAL-selected massive clumps (Csengeri+, 2016)
ATLASGAL-selected massive clumps in the inner Galaxy.
II. Characterisation of different evolutionary stages and their SiO emission.
Csengeri T., Leurini S., Wyrowski F., Urquhart J.S., Menten K.M.,
Walmsley M., Bontemps S., Wienen M., Beuther H., Motte F., Nguyen-Luong Q.,
Schilke P., Schuller F., Zavagno A., Sanna C.
<Astron. Astrophys. 586, A149 (2016)>
=2016A&A...586A.149C 2016A&A...586A.149C (SIMBAD/NED BibCode)
ADC_Keywords: Millimetric/submm sources ; Molecular clouds; Interstellar medium
Keywords: surveys - stars: massive - stars: formation - ISM: abundances -
ISM: jets and outflows
Abstract:
The processes leading to the birth of high-mass stars are poorly
understood. The key first step to reveal their formation processes is
characterising the clumps and cores from which they form.
We define a representative sample of massive clumps in different
evolutionary stages selected from the APEX Telescope Large Area Survey
of the Galaxy (ATLASGAL), from which we aim to establish a census of
molecular tracers of their evolution. As a first step, we study the
shock tracer, SiO, mainly associated with shocks from jets probing
accretion processes. In low-mass young stellar objects (YSOs), outflow
and jet activity decreases with time during the star formation
processes. Recently, a similar scenario was suggested for massive
clumps based on SiO observations. Here we analyse observations of the
SiO (2-1) and (5-4) lines in a statistically significant sample to
constrain the change of SiO abundance and the excitation conditions as
a function of evolutionary stage of massive star-forming clumps.
We performed an unbiased spectral line survey covering the 3-mm
atmospheric window between 84-117GHz with the IRAM 30m telescope
of a sample of 430 sources of the ATLASGAL survey, covering various
evolutionary stages of massive clumps. A smaller sample of 128 clumps
has been observed in the SiO (5-4) transition with the APEX
telescope to complement the (2-1) line and probe the excitation
conditions of the emitting gas. We derived detection rates to assess
the star formation activity of the sample, and we estimated the column
density and abundance using both an LTE approximation and non-LTE
calculations for a smaller subsample, where both transitions have been
observed.
Description:
List of sources selected for the spectroscopic survey with SiO (2-1)
and SiO (5-4) line parameters.
For more details see the corresponding section of the paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 94 430 List of ATLASGAL sources
table6.dat 66 301 SiO (2-1) line parameters and column density
table7.dat 49 114 SiO (5-4) line parameters
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See also:
J/A+A/549/A45 : ATLASGAL Compact Source Catalog: 330<l<21 (Contreras+, 2013)
J/A+A/568/A41 : ATLASGAL Compact Source Catalog: 280<l<60 (Urquhart+, 2014)
J/A+A/570/A65 : ATLASGAL massive clumps CO depletion (Giannetti+, 2014)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Source name (GLL.ll+B.bb)
13- 20 F8.4 deg RAdeg Right ascension (J2000)
22- 29 F8.4 deg DEdeg Declination (J2000)
31- 46 A16 --- AGsource ATLASGAL source (GLLL.llll+B.bbb)
48- 51 F4.1 arcsec offset ?=- Offset from ATLASGAL source
53- 57 F5.2 kpc Dist ?=- Distance estimate
59- 64 I6 Msun Mass ?=- Mass estimate from dust
66- 72 E7.2 cm-2 NH2 ?=- Beam averaged H2 column density
74- 78 F5.2 g/cm+2 Sigma ?=- Surface density
80- 94 A15 --- Class Classification
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Source name (GLL.ll+B.bb)
12 A1 --- m_Name [AB] Multiplicty index on Name
14- 21 F8.4 deg RAdeg Right ascension (J2000)
23- 30 F8.4 deg DEdeg Declination (J2000)
32- 37 F6.2 km/s Vlsr Rest velocity of the source
39- 41 I3 km/s DVl Velocity range of SiO (2-1) emission
43- 45 I3 km/s DVu Velocity range of SiO (2-1) emission
47- 51 F5.2 K.km/s Tint Integrated intensity on Tmb scale
53- 56 F4.2 K rms RMS noise per channel
58 A1 --- wings [y/n] Presence of line wings
60- 66 E7.2 cm-2 NSiO SiO column density based on LTE approximation
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Source name (GLL.ll+B.bb)
14- 21 F8.4 deg RAdeg Right ascension (J2000)
23- 30 F8.4 deg DEdeg Declination (J2000)
32- 34 I3 km/s DVl Velocity range of SiO (2-1) emission
36- 38 I3 km/s DVu Velocity range of SiO (2-1) emission
40- 44 F5.2 K.km/s Tint Integrated intensity on Tmb scale
46- 49 F4.2 K rms rms noise per channel
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Acknowledgements:
Timea Csengeri, csengeri(at)mpifr-bonn.mpg.de
References:
Giannetti et al., Paper I 2014A&A...570A..65G 2014A&A...570A..65G, Cat. J/A+A/570/A65
(End) Patricia Vannier [CDS] 20-Nov-2015