Far-infrared hydrogen lasers in the peculiar star MWC 349A

Science

Volumn 272, Issue 5267, 1996, Pages 1459-1461

  Strelnitski, Vladimir ^a   Haas, Michael R ^b   Smith, Howard A ^a   Erickson, Edwin F ^b   Colgan, Sean W J ^b,c   Hollenbach, David J ^b  

^a SMITHSONIAN INSTITUTION   (United States)

^b NASA AMES RESEARCH CENTER   (United States)

^c Search for Extra terrestrial I I   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

HYDROGEN;

ARTICLE; ASTRONOMY; LASER; MICROCLIMATE;

ASTRONOMY; EXTRATERRESTRIAL ENVIRONMENT; HYDROGEN; LASERS;

EID: 0030573461     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.272.5267.1459     Document Type: Article

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45. Laser amplification requires velocity coherence along the line of sight. In a narrow Keplerian ring seen edge-on, the coherent path is maximum along the two longest line-of-sight chords. Because of rotation, the chords produce two spectral components that are red-shifted and blue-shifted, respectively, relative to the central star. If the ring is wide, the gain along the central diameter can also be sufficient to produce an amplified component at zero Doppler-shift.
46. We gratefully acknowledge the KAO staff for their support of our expedition to Hawaii, J. Baltz for his laboratory and flight support, and R. Squire for useful comments and for suggesting the format of Fig. 3. Supported by NASA and the Smithsonian Institution.