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Title: DISCOVERY OF DRAMATIC OPTICAL VARIABILITY IN SDSS J1100+4421: A PECULIAR RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXY?

We present our discovery of dramatic variability in SDSS J1100+4421 by the high-cadence transient survey Kiso Supernova Survey. The source brightened in the optical by at least a factor of three within about half a day. Spectroscopic observations suggest that this object is likely a narrow-line Seyfert 1 galaxy (NLS1) at z = 0.840, however, with unusually strong narrow emission lines. The estimated black hole mass of ∼10{sup 7} M {sub ☉} implies bolometric nuclear luminosity close to the Eddington limit. SDSS J1100+4421 is also extremely radio-loud, with a radio loudness parameter of R ≅ 4 × 10{sup 2}-3 × 10{sup 3}, which implies the presence of relativistic jets. Rapid and large-amplitude optical variability of the target, reminiscent of that found in a few radio- and γ-ray-loud NLS1s, is therefore produced most likely in a blazar-like core. The 1.4 GHz radio image of the source shows an extended structure with a linear size of about 100 kpc. If SDSS J1100+4421 is a genuine NLS1, as suggested here, this radio structure would then be the largest ever discovered in this type of active galaxies.
Authors:
 [1] ; ; ;  [2] ;  [3] ; ; ;  [4] ;  [5] ; ;  [6] ;  [7] ;  [8] ; ; ;  [9] ;  [10] ; ;  [11] ;  [12] more »; « less
  1. National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)
  2. Institute of Astronomy, School of Science, University of Tokyo, Mitaka, Tokyo 181-0015 (Japan)
  3. Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)
  4. Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)
  5. Department of Physics, Faculty of Science and Engineering, Konan University, Kobe, Hyogo 658-8501 (Japan)
  6. Department of Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan)
  7. Institute of Space and Astronautical Science, JAXA, Sagamihara, Kanagawa 252-5210 (Japan)
  8. Department of Physics, Durham University, Durham DH1-3LE (United Kingdom)
  9. National Research Institute of Astronomy and Geophysics, Helwan, Cairo (Egypt)
  10. Kiso Observatory, Institute of Astronomy, School of Science, The University of Tokyo, Kiso, Nagano 397-0101 (Japan)
  11. Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile)
  12. Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States)
Publication Date:
OSTI Identifier:
22364969
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 793; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; BOLOMETERS; COSMIC GAMMA SOURCES; COSMIC RADIO SOURCES; EMISSION SPECTRA; GHZ RANGE; IMAGES; JETS; LUMINOSITY; MASS; RELATIVISTIC RANGE; SEYFERT GALAXIES; TRANSIENTS