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Published May 1983 | Published
Journal Article Open

Observations of the line profile of Paschen alpha in 3C 273


Within the uncertainties, the Pα line profile is the same as those of Hβ, Lα, and C IV. It is therefore contended that if current models of broad-line-emitting clouds in quasars are correct, then the similarity of the Pα line profile to the Lα profile argues against a velocity field dominated by radial inflow or outflow. It is noted, however, that if the cloud motions are predominantly due to radial inflow or outflow, then the clouds must radiate more isotropically in Lα then current models predict. The observed similarity of the line profiles of Pα at 1.875 microns and of C IV at 1550 A leads to the conclusion that there is no differential reddening caused by dust between clouds moving at different velocities within the broad line region of 3C 273.

Additional Information

© 1983 Astronomical Society of the Pacific. Received 1983 January 6. We would like to thank our night assistant J. Carrasco at Palomar Observatory for help with the observations; D. Nadeau, J. L. Lacy, and T. R. Geballe for invaluable help with the equipment; and R. L. White for useful discussions. Financial support was provided by grants from NASA and NSF.

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Published - 1983PASP___95__289S.pdf


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