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Infra-Red Sources in the H II Region W₃

Wynn-Williams, C. G. and Becklin, E. E. and Neugebauer, G. (1972) Infra-Red Sources in the H II Region W₃. Monthly Notices of the Royal Astronomical Society, 160 (1). pp. 1-14. ISSN 0035-8711. doi:10.1093/mnras/160.1.1.

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High resolution mapping and photometric observations in the wavelength range 1.65–20 µ have led to the discovery of nine distinct infra-red objects in W₃. Four of them, including one coincident with W₃ (OH), are identified with compact radio H II condensations ∼0.1 pc in diameter. They show strong emission in the range 3–20 µ which is attributable to dust grains at a temperature of ∼ 150 K mixed with the ionized gas. On the other hand, the 2-µ emission from these objects is considerably less than is predicted from the radio measurements, indicating that the H II condensations are surrounded by obscuring dust with up to 50 mag of visual extinction. One of the condensations contains an unresolved source which is almost certainly a highly obscured O star that excites the component. Four other infra-red sources have no associated radio continuum source; one of these, an unresolved source with a luminosity ∼3 × 10⁴ L⊙ is coincident with a source of H₂O maser emission and may be a massive protostar.

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Additional Information:© 1972 Royal Astronomical Society. Provided by the NASA Astrophysics Data System. Received 1972 July 24; Published: 01 October 1972. This work could not have been done without the support of the Caltech infra-red group; we especially thank J. Bennett, G. Forrester and L. Roberts for their assistance. We further thank T. Hilgeman who made some of the early infra-red measurements of W 3 with us, and our night assistants E. Hancock and J. Corresco for their help. Radio data were provided prior to publication by W. J. Wilson, and by R. Hills and W. J. Welch. P. Conti and C.R. O'Dell kindly commented on an early version of this paper. C.G.W-W. is grateful to the Commonwealth Fund for the receipt of a Harkness Fellowship and to Hale Observatories for guest observer's privileges. This work was supported in part by National Aeronautics and Space Administration Grants NGL 05-002-007 and NGL 05-002-207.
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NASANGL 05-002-007
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Official Citation:C. G. Wynn-Williams, E. E. Becklin, G. Neugebauer, Infra-Red Sources in the H II Region W 3, Monthly Notices of the Royal Astronomical Society, Volume 160, Issue 1, October 1972, Pages 1–14,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104481
Deposited By: Tony Diaz
Deposited On:21 Jul 2020 20:02
Last Modified:16 Nov 2021 18:32

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