J/MNRAS/477/3369 Young stellar objects in W49A and W51 (Eden+, 2018)
Extreme star formation in the Milky Way:
luminosity distributions of young stellar objects in W49A and W51.
Eden D.J., Moore T.J.T., Urquhart J.S., Elia D., Plume R., Konig C.,
Baldeschi A., Schisano E., Rigby A.J., Morgan L.K., Thompson M.A.
<Mon. Not. R. Astron. Soc., 477, 3369-3382 (2018)>
=2018MNRAS.477.3369E 2018MNRAS.477.3369E (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region ; YSOs ; Morphology
Keywords: stars: formation - ISM: individual objects: W49A -
ISM: individual objects: W51
Abstract:
We have compared the star-formation properties of the W49A and W51
regions by using far-infrared data from the Herschel infrared Galactic
Plane Survey (Hi-GAL) and 850-um observations from the James Clerk
Maxwell Telescope (JCMT) to obtain luminosities and masses,
respectively, of associated compact sources. The former are infrared
luminosities from the catalogue of Elia et al., while the latter are
from the JCMT Plane survey source catalogue as well as measurements
from new data. The clump-mass distributions of the two regions are
found to be consistent with each other, as are the clump-formation
efficiency and star-formation efficiency analogues. However, the
frequency distributions of the luminosities of the young stellar
objects are significantly different. While the luminosity distribution
in W51 is consistent with Galaxy-wide samples, that of W49A is top
heavy. The differences are not dramatic and are concentrated in the
central regions of W49A. However, they suggest that physical
conditions there, which are comparable in part to those in
extragalactic starbursts, are significantly affecting the
star-formation properties or evolution of the dense clumps in the
region.
Description:
The two regions, W51 and W49A, were imaged in the 850-um continuum by
the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) instrument
on the JCMT at an angular resolution of 14.4-arcsec. The W51 data
are taken from the JCMT Plane Survey (JPS) where the compact sources
are catalogued in Eden et al. (2017MNRAS.469.2163E 2017MNRAS.469.2163E, Cat.
J/MNRAS/469/2163). The W49A data were obtained in standard time
allocations under Project IDs m13bu27 and m14au23.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 84 171 The W49A JCMT catalogue
tableb1.dat 32 293 The JPS sources associated with the W51
star-forming region
tableb2.dat 20 57 The Hi-GAL sources associated with the
W49A star-forming region
tableb3.dat 20 434 The Hi-GAL sources associated with the
W51 star-forming region
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See also:
J/MNRAS/469/2163 : JCMT Plane Survey. First complete data release (Eden+, 2017)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name W49A Source Catalogue Name (W49_NNN)
9- 14 F6.3 deg GLON Galactic longitude of peak position
16- 21 F6.3 deg GLAT Galactic latitude of peak position
23- 28 F6.3 deg GLONc Galactic longitude of central position
30- 35 F6.3 deg GLATc Galactic latitude of central position
37- 38 I2 arcsec amaj Semi-major axis
40- 41 I2 arcsec bmin Semi-minor axis
43- 45 I3 deg PA Position angle of source
47- 48 I2 arcsec Reff Effective radius of the source
50- 55 F6.3 Jy/beam Fpeak Peak flux at 850um
57- 61 F5.3 Jy/beam e_Fpeak Error on the peak flux
63- 68 F6.3 Jy Fint Integrated flux at 850um
70- 74 F5.3 Jy e_Fint Error on the integrated flux
76- 82 F7.2 --- SNR Signal-to-noise ratio
84 A1 --- W49Aflag [y/n] Flag if the source is associated
with W49A
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- JPS JPS Compact Source Catalogue ID
(JPSGLLL.lll+BB.bbb)
20- 25 F6.3 deg GLON Galactic longitude of peak position
27- 32 F6.3 deg GLAT Galactic latitude of peak position
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Byte-by-byte Description of file: tableb2.dat tableb3.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- Hi-GAL Hi-GAL Source ID
8- 13 F6.3 deg GLON Galactic longitude of peak position
15- 20 F6.3 deg GLAT Galactic latitude of peak position
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 10-Jun-2021