Mid-infrared imaging of Orion BN/KL. II. Luminosity sources, extinction distribution, and the nature of IRc2

被引:108
作者
Gezari, DY
Backman, DE
Werner, MW
机构
[1] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[2] Franklin & Marshall Coll, Dept Phys & Astron, Lancaster, PA 17604 USA
[3] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
关键词
infrared : ISM : continuum; ISM : individual (Orion-BN); ISM : individual (Orion Kleinmann-Low);
D O I
10.1086/306462
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We have recalculated the luminosities of IRc2 and the BN Object in the Orion BN/KL complex and determined the distributions of color temperature and silicate absorption-line strength over the region with much greater precision than before, using a complete set of well-sampled and nearly diffraction-limited array camera images of BN/KL at nine wavelengths between 4.8 and 20 mu m. We find that the total infrared luminosity of IRc2 itself is only L similar to 1000 L. (much lower than the generally accepted value). However, the temperature and extinction distributions show that the significant luminosity source(s) in BN/KL must still be located within several arcseconds of IRc2. Our results, considered with recent radio continuum and maser emission observations, suggest that a luminous early-type star located at radio source "I" is embedded close to IRc2, obscured by similar to 60 mag of visual extinction from dust grains both local to IRc2 and in intervening clouds along the line of sight. The combined heating contributions of the hot stars ionizing the compact H II regions "I" (near IRc2), "B" (the BN Object), and "L" (infrared source "n"), compact IRc objects (including 10 new peaks resolved here), and distributed near-infrared sources can account for the observed similar to 10(5) L. total luminosity of the BN/KL complex.
引用
收藏
页码:283 / 298
页数:16
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