J/MNRAS/460/4150 JCMT Gould Belt Survey: W40 complex (Rumble+, 2016)
The JCMT Gould Belt Survey:
evidence for radiative heating and contamination in the W40 complex.
Rumble D., Hatchell J., Pattle K., Kirk H., Wilson T., Buckle J.,
Berry D.S., Broekhoven-Fiene H., Currie M.J., Fich M., Jenness T.,
Johnstone D., Mottram J.C., Nutter D., Pineda J.E., Quinn C., Salji C.,
Tisi S., Walker-Smith S., Di Francesco J., Hogerheijde M.R.,
Ward-Thompson D., Bastien P., Bresnahan D., Butner H., Chen M.,
Chrysostomou A., Coude S., Davis C.J., Drabek-Maunder E., Duarte-Cabral A.,
Fiege J., Friberg P., Friesen R., Fuller G.A., Graves S., Greaves J.,
Gregson J., Holland W., Joncas G., Kirk J.M., Knee L.B.G., Mairs S.,
Marsh K., Matthews B.C., Moriarty-Schieven G., Mowat C., Rawlings J.,
Richer J., Robertson D., Rosolowsky E., Sadavoy S., Thomas H., Tothill N.,
Viti S., White G.J., Wouterloot J., Yates J., Zhu M.
<Mon. Not. R. Astron. Soc., 460, 4150-4175 (2016)>
=2016MNRAS.460.4150R 2016MNRAS.460.4150R (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; YSOs ; Photometry, millimetric/submm ;
Stars, masses
Keywords: radiative transfer - catalogues; stars: formation; H II regions -
submillimetre: general
Abstract:
We present SCUBA-2 450µm and 850µm observations of the W40
complex in the Serpens-Aquila region as part of the James Clerk
Maxwell Telescope (JCMT) Gould Belt Survey (GBS) of nearby
star-forming regions. We investigate radiative heating by constructing
temperature maps from the ratio of SCUBA-2 fluxes using a fixed dust
opacity spectral index, β=1.8, and a beam convolution kernel to
achieve a common 14.8-arcsec resolution. We identify 82 clumps ranging
between 10 and 36K with a mean temperature of 20±3K. Clump
temperature is strongly correlated with proximity to the external OB
association and there is no evidence that the embedded protostars
significantly heat the dust. We identify 31 clumps that have cores
with densities greater than 105cm-3. 13 of these cores contain
embedded Class 0/I protostars. Many cores are associated with
bright-rimmed clouds seen in Herschel 70µm images. From JCMT HARP
observations of the 12CO 3-2 line, we find contamination of the
850µm band of up to 20 per cent. We investigate the free-free
contribution to SCUBA-2 bands from large-scale and ultracompact HII
regions using archival VLA data and find the contribution is limited
to individual stars, accounting for 9 per cent of flux per beam at
450µm or 12 per cent at 850µm in these cases. We conclude that
radiative heating has potentially influenced the formation of stars in
the Dust Arc sub-region, favouring Jeans stable clouds in the warm
east and fragmentation in the cool west.
Description:
Aquila was observed with SCUBA-2 (Holland et al., 2013MNRAS.430.2513H 2013MNRAS.430.2513H)
between 2012 April 21 and July 5 as part of the JCMT GBS MJLSG33
SCUBA-2 Serpens Campaign. Four separate fully sampled 30 arcmin
diameter circular continuum observations (PONG1800 mapping mode) were
taken simultaneously at 850um and 450um, and subsequently combined
into mosaics.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 60 267 *Our composite YSO catalogue
table5.dat 312 82 Submillimetre clumps and their respective
SCUBA-2 and Herschel fluxes and properties
in the W40 complex
table7.dat 114 31 Dense cores in the W40 complex
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Note on table2.dat: produced from the combined SGBS (Dunham et al., 2015,
Cat. J/ApJS/220/11), the Mallick et al. (2013, Cat. J/ApJ/779/113)
Spitzer catalogue, the Maury et al. (2011A&A...535A..77M 2011A&A...535A..77M) MAMBO catalogue,
the Kuhn etal. (2010, Cat. J/ApJ/725/2485) X-ray catalogue, and the
Rodriguez et al. (2010, Cat. J/AJ/140/968) catalogue of radio YSOs.
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See also:
J/ApJ/725/2485 : X-rays from the star-forming complex W40 (Kuhn+, 2010)
J/AJ/140/968 : A cluster of compact radio sources in W40 (Rodriguez+, 2010)
J/ApJ/779/113 : IR photometry of YSOs in the W40 region (Mallick+, 2013)
J/ApJS/220/11 : SEDs of Spitzer YSOs in the Gould Belt (Dunham+, 2015)
Byte-by-byte Description of file:table2.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name 2MASS or CXO name (2MASSHHMMSSss+DDMMSSss,
CXOHHMMSS.ss+BBMMSS.s) or position
(HH:MM:SS-DD:MM:SS.s)
24 I1 --- Class [0/4] YSO class
26- 36 F11.7 deg RAdeg Right ascension (J2000)
38- 49 F12.9 deg DEdeg Declination (J2000)
51- 55 F5.2 --- alphaE ? Spectroscopic index (1)
57- 60 I4 K TbolE ? Bolometric temperature (1)
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Note (1): as published by Dunham et al. (2015, Cat. J/ApJS/220/11)
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/82] Sequential number
4- 11 F8.4 deg RAdeg Right ascension (J2000)
13- 19 F7.4 deg DEdeg Declination (J2000)
21- 25 F5.2 Jy F450 Integrated SCUBA-2 flux at 450um over the
clump properties (1)
27- 32 F6.3 Jy F850 Integrated SCUBA-2 flux at 850um over the
clump properties (2)
34- 49 F16.11 MJy/sr FH70 Mean Herschel 70um intensity.
51- 67 E17.15 Jy F21cm Mean VLA 21cm intensity at 15 arcsec pixels
69- 84 F16.13 Msun Mass Mass (3)
86-100 F15.13 Msun e_Mass rms uncertainty on Mass
102-114 F13.10 K Temp Mean temperature as calculated from the
temperature maps
116-129 F14.12 K e_Temp rms uncertainty on Temp (4)
131-147 F17.11 10+21cm-2 CD Peak column density of the clump
(in 1021H2/cm2)
149-162 F14.11 10+21cm-2 e_CD rms uncertainty on CD
(in 1021H2/cm2) (5)
164-179 F16.14 pc Diam Flux weighted effective diameter
181-194 F14.7 cm-3 Dens Average volume density of a dense core
along the line of sight
196-211 F16.12 pc-2 YSOD YSO density (YSO per pc2) (6)
213-227 F15.13 pc-2 e_YSOD rms uncertainty on YSO
229 I1 --- sumPROTO Number of protostars per clump (6)
231-245 F15.12 Msun MJ Jean mass (7)
247-260 F14.12 Msun e_MJ rms uncertainty on MJ
262-276 F15.13 --- M/MJ Mass ratio
278-292 F15.13 --- e_M/MJ rms uncertainty on M/MJ
294-308 F15.13 pc Dist Projected distance between clump and OS1a,
the primary ionizing star in the W40
complex OB association
310-312 I3 pix Area Clump area
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Note (1): The uncertainty at 450um is 0.017Jy/pix. There is an additional
systematic error in calibration of 10.6 per cent at 450um.
Note (2): The uncertainty at 850um is 0.0025Jy/pix. There is an additional
systematic error in calibration of 3.4 per cent at 850um.
Note (3): As calculated with equation (5). These results do not include the
systematic error in distance (10 per cent) or opacity (up to a factor of 2).
Note (4): Uncertainty is the mean pixel standard deviation, as propagated
through the method. Where no temperature data are available an arbitrary value
of 15±2K is assigned that is consistent with previous authors
(Johnstone et al., 2000ApJ...545..327J 2000ApJ...545..327J; Kirk et al., 2006, Cat. J/ApJ/646/1009;
Rumble et al., 2015, Cat. J/MNRAS/448/1551).
Note (5): These results do not include the systematic error in distance or
opacity .
Note (6): calculated from the composite YSO catalogue outlined in Section 2.3
Note (7): as calculated with equation (7). These results do not include the
systematic error in distance.
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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- 2 I2 --- Seq [1/62] Sequential number (Clump ID, W40-SMM),
as in table 5
4- 11 F8.4 deg RAdeg Right ascension (J2000)
13- 19 F7.4 deg DEdeg Declination (J2000)
21- 35 F15.12 Msun Mass Mass
37- 51 F15.13 Msun e_Mass rms uncertainty on Mass
53- 67 F15.13 pc Diam Flux weighted effective diameter (1)
69- 81 F13.6 cm-3 Dens Average volume density of a dense core along
the line of sight (2)
83 I1 --- sumPROTO ?=- Number of protostars per clump (3)
85- 98 F14.12 --- M/MJ Mass ratio
100-114 F15.13 --- e_M/MJ Mass ratio
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Note (1): Flux weighted effective diameter as calculated by the clump-finding
algorithm FELLWALKER (values were not deconvolved with respect to the JCMT
beam).
Note (2): Each observation is a lower limit as effective size of the cloud is
typically larger than a core. A dense core is defined where the density limit
is greater than 105cm-3, a value five times greater than the typical
density of a star forming filament (2x104cm-3, Andre et al., 2014, in
Protostars and Planets VI, Tuscon, Univ. Arizona Press, 27) and where the gas
and dust temperatures are well coupled (Goldsmith, 2001ApJ...557..736G 2001ApJ...557..736G).
Note (3): - for clumps beyond the coverage of our composite YSO catalogue.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 24-Nov-2017