Newly discovered Footprints of Galaxy Interaction around Sefert 2 galaxy NGC 7743

  • Kim, Yongjung (CEOU, Dept. of Physics and Astronomy, Seoul National University) ;
  • Im, Myungshin (CEOU, Dept. of Physics and Astronomy, Seoul National University) ;
  • Choi, Changsu (CEOU, Dept. of Physics and Astronomy, Seoul National University) ;
  • Hyun, Minhee (CEOU, Dept. of Physics and Astronomy, Seoul National University) ;
  • Yoon, Yongmin (CEOU, Dept. of Physics and Astronomy, Seoul National University) ;
  • Taak, Yoonchan (CEOU, Dept. of Physics and Astronomy, Seoul National University)
  • Published : 2014.04.10

Abstract

It has been suggested that only the most luminous AGNs ($L{\geq}$ [10] $^{45}L_{\odot}$ ) are triggered by galaxy mergers, while less luminous AGNs (L~ [10] $^{43}L_{\odot}$) are driven by other internal processes. Lack of merging features in low luminosity AGN host galaxies has been a main argument against the idea of merger triggering of low luminosity AGNs, but merging, especially a rather minor one, might still have played an important role in low luminosity AGNs since minor merging features in low luminosity are more difficult to identify than major merging features. Using SNUCAM on the 1.5m telescope at Madanak observatory, we obtained deep images of NGC 7743 which is a barred spiral galaxy classified as a Seyfert 2 AGN with a low bolometric luminosity of $5{\times}$ [10] $^{42}L_{\odot}$. Surprisingly, we newly discovered merging features around the galaxy, which indicate past merging activity on the galaxy. This example indicates the merging fraction of low luminosity AGNs may be much higher than previously thought, hinting the importance of galaxy merger even in low luminosity AGN.

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