Gear, Walter Kieran 1991. Are BL Lac objects too large to be gravitationally lensed? Nature 349 (6311) , pp. 676-678. 10.1038/349676a0 |
Abstract
BL LACERTAEobjects are extragalactic sources, generally of low redshift, with highly variable, strongly polarized continuum emission ranging from radio wavelengths to X-rays, but with little or no evidence of line emission. It has been suggested1that BL Lacs are in fact more distant radio-loud, optically violently variable (OVV) quasars whose continuum is enhanced, relative to the line emission, by gravitational lensing caused by a star in an intervening galaxy. I argue here, however, that the spectral similarity of BL Lacs and OWs over a wide wavelength range can be explained by gravitational lensing only if the continuum-emitting region is small, a requirement that is contradicted by independent observations.
Item Type: | Article |
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Date Type: | Publication |
Status: | Published |
Schools: | Physics and Astronomy |
Subjects: | Q Science > QB Astronomy |
Publisher: | Macmillan Publishers Ltd. |
ISSN: | 0028-0836 |
Last Modified: | 04 Jun 2017 04:17 |
URI: | http://orca.cf.ac.uk/id/eprint/36076 |
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