University of Hertfordshire

By the same authors

Monitoring the Ha Line in BL Lacertae - Evidence for an Accretion Disk

Research output: Chapter in Book/Report/Conference proceedingConference contribution


  • E.A. Corbett
  • A. Robinson
  • J. Hough
  • D.J. Axon
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Original languageEnglish
Title of host publicationIn: Procs of Structure and Kinematics of Quasar Broad Line Regions, ASP Conference Series 175
PublisherAstronomical Society of the Pacific
ISBN (Print)1-886733-97-X
Publication statusPublished - 1999


We present new spectroscopic observations of the recently discovered broad Ha line in BL Lacertae. These data, obtained over a period of 30 months, indicate that the line equivalent width is anti-correlated with the continuum flux, implying that the broad line emission is not powered primarily by synchroton emission from the relativistic jet. The most probable explanation is that the broad line region in BL Lacertae is photoionized by continuum emission from an accretion disk which at optical wavelengths is dominated by the Doppler beamed synchroton continuum.


Original paper can be found at: Astronomical Society of the Pacific

ID: 160704