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

Sellgren, K. and Soifer, B. T. and Neugebauer, G. and Matthews, K. (1983) Observations of the line profile of Paschen alpha in 3C 273. Publications of the Astronomical Society of the Pacific, 95 (567). pp. 289-292. ISSN 0004-6280. doi:10.1086/131160.

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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.

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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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Subject Keywords:quasars—3C 273—infrared spectra—line profiles
Issue or Number:567
Record Number:CaltechAUTHORS:20170308-090620867
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Official Citation:K. Sellgren et al 1983 PASP 95 289
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:74887
Deposited By: Tony Diaz
Deposited On:08 Mar 2017 17:25
Last Modified:15 Nov 2021 16:28

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