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

Abstract

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
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 793; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
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

Citation Formats

Tanaka, Masaomi, Morokuma, Tomoki, Doi, Mamoru, Kikuchi, Yuki, Itoh, Ryosuke, Akitaya, Hiroshi, Tanaka, Yasuyuki T., Kawabata, Koji S., Tominaga, Nozomu, Saito, Yoshihiko, Kawai, Nobuyuki, Stawarz, Łukasz, Gandhi, Poshak, Ali, Gamal, Essam, Ahmad, Hamed, Gamal, Aoki, Tsutomu, Contreras, Carlos, Hsiao, Eric Y., Iwata, Ikuru, and others, and. DISCOVERY OF DRAMATIC OPTICAL VARIABILITY IN SDSS J1100+4421: A PECULIAR RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXY?. United States: N. p., 2014. Web. doi:10.1088/2041-8205/793/2/L26.
Tanaka, Masaomi, Morokuma, Tomoki, Doi, Mamoru, Kikuchi, Yuki, Itoh, Ryosuke, Akitaya, Hiroshi, Tanaka, Yasuyuki T., Kawabata, Koji S., Tominaga, Nozomu, Saito, Yoshihiko, Kawai, Nobuyuki, Stawarz, Łukasz, Gandhi, Poshak, Ali, Gamal, Essam, Ahmad, Hamed, Gamal, Aoki, Tsutomu, Contreras, Carlos, Hsiao, Eric Y., Iwata, Ikuru, & others, and. DISCOVERY OF DRAMATIC OPTICAL VARIABILITY IN SDSS J1100+4421: A PECULIAR RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXY?. United States. https://doi.org/10.1088/2041-8205/793/2/L26
Tanaka, Masaomi, Morokuma, Tomoki, Doi, Mamoru, Kikuchi, Yuki, Itoh, Ryosuke, Akitaya, Hiroshi, Tanaka, Yasuyuki T., Kawabata, Koji S., Tominaga, Nozomu, Saito, Yoshihiko, Kawai, Nobuyuki, Stawarz, Łukasz, Gandhi, Poshak, Ali, Gamal, Essam, Ahmad, Hamed, Gamal, Aoki, Tsutomu, Contreras, Carlos, Hsiao, Eric Y., Iwata, Ikuru, and others, and. 2014. "DISCOVERY OF DRAMATIC OPTICAL VARIABILITY IN SDSS J1100+4421: A PECULIAR RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXY?". United States. https://doi.org/10.1088/2041-8205/793/2/L26.
@article{osti_22364969,
title = {DISCOVERY OF DRAMATIC OPTICAL VARIABILITY IN SDSS J1100+4421: A PECULIAR RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXY?},
author = {Tanaka, Masaomi and Morokuma, Tomoki and Doi, Mamoru and Kikuchi, Yuki and Itoh, Ryosuke and Akitaya, Hiroshi and Tanaka, Yasuyuki T. and Kawabata, Koji S. and Tominaga, Nozomu and Saito, Yoshihiko and Kawai, Nobuyuki and Stawarz, Łukasz and Gandhi, Poshak and Ali, Gamal and Essam, Ahmad and Hamed, Gamal and Aoki, Tsutomu and Contreras, Carlos and Hsiao, Eric Y. and Iwata, Ikuru and others, and},
abstractNote = {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.},
doi = {10.1088/2041-8205/793/2/L26},
url = {https://www.osti.gov/biblio/22364969}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 793,
place = {United States},
year = {Wed Oct 01 00:00:00 EDT 2014},
month = {Wed Oct 01 00:00:00 EDT 2014}
}