2003/02/10 by Gopal-Krishna, Gopal‐Krishna, C. S. Stalin +3 · 81 citations
Physics and Astronomy · #Active galactic nucleus #Amplitude #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #BL Lac object #Blazar #Duty cycle #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma ray #Luminosity #Optics #Physics #QUIET #Quasar #Radio Astronomy Observations and Technology #Redshift #Relativistic beaming #Sky #astro-ph
paper · pdf · doi:10.1086/374655
published in The Astrophysical Journal 586(1), L25-L28 (IOP Publishing) · 13 pages, 3 figures, in press in ApJ Letters (20 March 2003)
arxiv created 2003/02/10 · openalex publication_date 2003/03/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present new clues to the problem of the radio loudness dichotomy arising from an extensive search for intranight optical variability in seven sets of optically luminous radio-quiet quasars and (radio-loud) BL Lacertae objects, which are matched in optical luminosity and redshift. Our monitoring of radio-quiet quasars has for the first time clearly detected such intranight variability, with peak-to-peak amplitudes ~1%, occurring with a duty cycle of ~ . The matched BL Lac objects have both higher variability amplitudes and duty cycles when observed in the same fashion. We show that the much less pronounced intranight variability of the radio-quiet quasars relative to BL Lac objects can be understood in terms of a modest misalignment of the jets in radio-quiet quasars from the line of sight. We thus infer that relativistic particle jets may well also emerge from radio-quiet quasars, but while traversing the short optical-emitting distances, they could be snuffed out, possibly through inverse Compton losses in the nuclear region.