J/MNRAS/448/1551 JCMT Gould Belt Survey: Serpens MWC 297 (Rumble+, 2015)
The JCMT Gould Belt Survey: evidence for radiative heating in Serpens MWC 297
and its influence on local star formation.
Rumble D., Hatchell J., Gutermuth R.A., Kirk H., Buckle J., Beaulieu S.F.,
Berry D.S., Broekhoven-Fiene H., Currie M.J., Fich M., Jenness T.,
Johnstone D., Mottram J.C., Nutter D., Pattle K., Pineda J.E., Quinn C.,
Salji C., Tisi S., Walker-Smith S., Di Francesco J., Hogerheijde M.R.,
Ward-thompson D., Allen L.E., Cieza L.A., Dunham M.M., Harvey P.M.,
Stapelfeldt K.R., Bastien P., 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., Rawlings J., Richer J., Robertson D.,
Rosolowsky E., Sadavoy S., Thomas H., Tothill N., Viti S., White G.J.,
Wilson C.D., Wouterloot J., Yates J., Zhu M.
<Mon. Not. R. Astron. Soc., 448, 1551-1573 (2015)>
=2015MNRAS.448.1551R 2015MNRAS.448.1551R (SIMBAD/NED BibCode)
ADC_Keywords: H II regions; YSOs ; Photometry, millimetric/submm
Keywords: radiative transfer - catalogues - stars: formation -
stars: protostars - HII regions - submillimetre: general
Abstract:
We present SCUBA-2 450 and 850µm observations of the Serpens MWC
297 region, part of the James Clerk Maxwell Telescope (JCMT) Gould
Belt Survey of nearby star-forming regions. Simulations suggest that
radiative feedback influences the star formation process and we
investigate observational evidence for this by constructing
temperature maps. Maps are derived from the ratio of SCUBA-2 fluxes
and a two-component model of the JCMT beam for a fixed dust opacity
spectral index of β=1.8. Within 40-arcsec of the B1.5Ve Herbig
star MWC 297, the submillimetre fluxes are contaminated by free-free
emission with a spectral index of 1.03±0.02, consistent with an
ultracompact HII region and polar winds/jets. Contamination accounts
for 73±5 per cent and 82±4 per cent of peak flux at 450µm and
850 µm, respectively. The residual thermal disc of the star is
almost undetectable at these wavelengths. Young stellar objects (YSOs)
are confirmed where SCUBA-2 850µm clumps identified by the
fellwalker algorithm coincide with Spitzer Gould Belt Survey
detections. We identify 23 objects and use Tbol to classify nine
YSOs with masses 0.09 to 5.1M☉. We find two Class 0, one Class
0/I, three Class I and three Class II sources. The mean temperature is
15±2K for the nine YSOs and 32±4K for the 14 starless clumps. We
observe a starless clump with an abnormally high mean temperature of
46±2K and conclude that it is radiatively heated by the star MWC
297. Jeans stability provides evidence that radiative heating by the
star MWC 297 may be suppressing clump collapse.
Description:
Serpens MWC 297 was observed with SCUBA-2 on the 2012 July 5 and 8 as
part of the JCMT GBS MJLSG33 SCUBA-2 Serpens Campaign.
Continuum observations at 850 and 450um were made using fully sampled
30 arcmin diameter circular regions centered on RA=18:28:13.8,
DE=-03:44:01.7 (J2000).
The MWC 297 region was observed twice by Spitzer in the mid-infrared,
first as part of the Spitzer Young Clusters Survey (SYC; Gutermuth et
al., 2009, Cat. J/ApJS/184/18) and secondly as part of the Spitzer
legacy programme 'Gould's Belt: star formation in the solar
neighbourhood' (SGBS, PID: 30574).
In both surveys, mapping observations were taken at 3.6, 4.5, 5.8 and
8.0um with the Infrared Array Camera (IRAC) and at 24um with the
Multiband Imaging Photometer for Spitzer (MIPS).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 106 83 SCUBA-2 40" aperture fluxes for the Spitzer
YSOcs in the MWC297 region
table3.dat 92 23 Fellwalker Clumps extracted from SCUBA-2 data
of the Serpens MWC297 region
table7.dat 43 83 Spitzer YSOc candidates in the MWC297 region
from the Spitzer Gould Belt survey
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [YSOc]
5- 6 I2 --- YSOc YSOc identification number
8- 24 A17 --- SSTgbs SSTgbs name (JHHMMSSss+DDMMSSs)
26- 31 F6.1 mJy S3.6 SCUBA-2 40" aperture 3.6um flux
33- 37 F5.1 mJy e_S3.6 rms uncertainty on S3.6
39- 44 F6.1 mJy S4.5 SCUBA-2 40" aperture 4.5um flux
46- 50 F5.1 mJy e_S4.5 rms uncertainty on S4.5
52- 58 F7.2 mJy S5.8 SCUBA-2 40" aperture 5.8um flux
60- 64 F5.2 mJy e_S5.8 rms uncertainty on S5.8
66- 72 F7.2 mJy S8.0 SCUBA-2 40" aperture 8.0um flux
74- 78 F5.2 mJy e_S8.0 rms uncertainty on S8.0
80- 85 F6.1 mJy S24 SCUBA-2 40" aperture 24um flux
87- 91 F5.1 mJy e_S24 rms uncertainty on S24
93- 96 I4 mJy S70 ?=0 SCUBA-2 40" aperture 70um flux
98-100 I3 mJy e_S70 ?=0 rms uncertainty on S70
102-106 F5.2 --- alpha IR spectral index
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [SMM]
4- 5 I2 --- SMM SMM clump identification number
6 A1 --- n_JCMTLSG [*] Note (1)
8- 14 A7 --- --- [JCMTLSG]
16- 31 A16 --- JCMTLSG JCMTLSG name (JHHMMSSs+DDMMSSs), position of
the highest value pixel in each clump
(at 850um)
33- 36 F4.1 Jy S450 Intergrated 450um flux of the clump as
determined by fellwalker (2)
38- 41 F4.1 Jy S840 Intergrated 840um flux of the clump as
determined by fellwalker (2)
43- 47 F5.2 Msun M850 Mass from 850um measurements (3)
49- 52 F4.2 Msun e_M850 rms uncertainty on M850 (4)
54- 57 F4.1 K T Mean temperature (5)
59- 61 F3.1 K e_T ?=- rms uncertainty on T (5)
63- 65 I3 pix Area Clump as identified by the FELLWALKER
algorithm
67- 70 F4.2 Msun MJ Jeans mass (6)
72- 75 F4.2 Msun e_MJ rms uncertainty on MJ (6)
77- 80 F4.2 --- M850/MJ Mass ratio
82- 85 F4.2 --- e_M850/MJ rms uncertainty on M850/MJ
87- 90 A4 --- --- [YSOc]
91- 92 I2 --- YSOc ? YSOc number SGBS (7)
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Note (1): * for objects that have been merged with an adjacent object which was
incorrectly identified as a separate clump by FELLWALKER.
Note (2): The uncertainty at 450um is 0.3Jy and at 850um is 0.02Jy. There is an
additional systematic error in calibration of 10.6 and 3.4 per cent
at 450 and 850um.
Note (3): As calculated with equation (6).
Note (4): Errors are calculated from error in total flux and error in mean
temperature of 5 per cent. These results do not include the systematic error
in distance (20 per cent) and opacity (100 per cent).
Note (5): Mean temperature as calculated from the temperature maps (Fig. 3).
Where no temperature data is available an arbitrary value of 15K(---) is
assigned that is consistent with the literature.
Note (6): As calculated with equation (7). These results have a systematic
error uncertainty due to distance of 20 per cent.
Note (7): Where a fellwalker source is coincident with an SGBS YSOc, that object
is listed here. A complete list is presented in Table 2.
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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- 4 A4 --- --- [YSOc]
5- 6 I2 --- YSOc YSOc identification number
8 A1 --- l_S450 Limit flag for 5-sigma upper limit on S450
9- 13 F5.2 Jy S450 40" aperture 450um flux
15- 18 F4.2 Jy e_S450 rms uncertainty on S450
20 A1 --- l_S850 Limit flag for 5-sigma upper limit on S850
21- 25 F5.3 Jy S850 40" aperture 850um flux
27- 31 F5.3 Jy e_S850 rms uncertainty on S850
33- 41 A9 --- S2 S2-YSOc identification number, S2-YSOcNN
43 A1 --- Note [ab] Note (1)
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Note (1): Note as follows:
a = Extended low level emission in aperture. No significant peak at YSOc
position (<3σ)
b = Outside data reduction mask. No significant flux detected in initial
data reduction stage (<5σ)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-Sep-2015