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New clues to jet launching: The inner disks in radio loud quasars may be more stable

  • ZhenYi CaiEmail author
  • YuHan SunEmail author
  • JunXian WangEmail author
  • FeiFan Zhu
  • WeiMin Gu
  • Feng Yuan
Article

Abstract

Jet launching in radio loud (RL) quasars is one of the fundamental problems in astrophysics. Exploring the differences in the inner accretion disk properties between RL and radio quiet (RQ) quasars might yield helpful clues to this puzzle. We previously discovered that the shorter term UV/optical variations of quasars are bluer than the longer term ones, i.e., the so-called timescale- dependent color variation. This is consistent with the scheme that the faster variations come from the inner and hotter disk regions, thus providing a useful tool to map the accretion disk which is otherwise unresolvable. In this work we compare the UV/optical variations of RL quasars in SDSS Stripe 82 to those of several RQ samples, including those matched in redshift-luminosity-black hole mass and/or color-magnitude. We find that while both RL and RQ populations appear bluer when they brighten, RL quasars potentially show a weaker/flatter dependence on timescale in their color variation. We further find that while both RL and RQ populations on average show similar variation amplitudes at long timescales, fast variations of RL sources appear weaker/smaller (at timescales of ~25-300 d in the observer’s frame), and the difference is more prominent in the g-band than in the r-band. Inhomogeneous disk simulations can qualitatively reproduce these observed differences if the inner accretion disk of RL quasars fluctuates less based on simple toy models. Though the implications are likely model dependent, the discovery points to an interesting diagram that magnetic fields in RL quasars may be prospectively stronger and play a key role in both jet launching and the stabilization of the inner accretion disk.

Keywords

accretion and accretion disks quasars galactic jets 

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Copyright information

© Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.CAS Key Laboratory for Research in Galaxies and Cosmology, Department of AstronomyUniversity of Science and Technology of ChinaHefeiChina
  2. 2.School of Astronomy and Space ScienceUniversity of Science and Technology of ChinaHefeiChina
  3. 3.Department of Astronomy and Astrophysics, 537 Davey LabThe Pennsylvania State UniversityUniversity ParkUSA
  4. 4.Department of AstronomyXiamen UniversityXiamenChina
  5. 5.Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghaiChina
  6. 6.SHAO-XMU Joint Center for AstrophysicsXiamen UniversityXiamenChina

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