Discovery of dramatic optical variability in SDSS J1100+4421: A peculiar radio-loud narrow-line Seyfert 1 galaxy?

Masaomi Tanaka, Tomoki Morokuma, Ryosuke Itoh, Hiroshi Akitaya, Nozomu Tominaga, Yoshihiko Saito, Łukasz Stawarz, Yasuyuki T. Tanaka, Poshak Gandhi, Gamal Ali, Tsutomu Aoki, Carlos Contreras, Mamoru Doi, Ahmad Essam, Gamal Hamed, Eric Y. Hsiao, Ikuru Iwata, Koji S. Kawabata, Nobuyuki Kawai, Yuki KikuchiNaoto Kobayashi, Daisuke Kuroda, Hiroyuki Maehara, Emiko Matsumoto, Paolo A. Mazzali, Takeo Minezaki, Hiroyuki Mito, Takashi Miyata, Satoshi Miyazaki, Kensho Mori, Yuki Moritani, Kana Morokuma-Matsui, Nidia Morrell, Tohru Nagao, Yoshikazu Nakada, Fumiaki Nakata, Chinami Noma, Ken Ohsuga, Norio Okada, Mark M. Phillips, Elena Pian, Michael W. Richmond, Devendra Sahu, Shigeyuki Sako, Yuki Sarugaku, Takumi Shibata, Takao Soyano, Maximilian D. Stritzinger, Yutaro Tachibana, Francesco Taddia, Katsutoshi Takaki, Ali Takey, Ken'Ichi Tarusawa, Takahiro Ui, Nobuharu Ukita, Yuji Urata, Emma S. Walker, Taketoshi Yoshii

Research output: Contribution to journalArticle

10 Citations (Scopus)

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 107M 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 × 102-3 × 103, 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.

Original languageEnglish
Article numberL26
JournalAstrophysical Journal Letters
Volume793
Issue number2
DOIs
Publication statusPublished - 2014 Oct 1
Externally publishedYes

Keywords

  • galaxies: Seyfert
  • galaxies: active
  • galaxies: individual (SDSS J110006.07+442144.3)
  • galaxies: jets

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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    Tanaka, M., Morokuma, T., Itoh, R., Akitaya, H., Tominaga, N., Saito, Y., Stawarz, Ł., Tanaka, Y. T., Gandhi, P., Ali, G., Aoki, T., Contreras, C., Doi, M., Essam, A., Hamed, G., Hsiao, E. Y., Iwata, I., Kawabata, K. S., Kawai, N., ... Yoshii, T. (2014). Discovery of dramatic optical variability in SDSS J1100+4421: A peculiar radio-loud narrow-line Seyfert 1 galaxy? Astrophysical Journal Letters, 793(2), [L26]. https://doi.org/10.1088/2041-8205/793/2/L26