Three-Dimensional Structure of Star-Forming Regions in NGC 6822 Hubble V

  • Lee, Hye-In (School of Space Research, Kyung Hee University) ;
  • Oh, Heeyoung (Korea Astronomy & Space Science institute) ;
  • Le, Huynh Anh N. (Department of Physics and Astronomy, Seoul National University) ;
  • Pak, Soojong (School of Space Research, Kyung Hee University) ;
  • Lee, Sungho (Korea Astronomy & Space Science institute) ;
  • Mace, Gregory (Department of Astronomy, the University of Texas) ;
  • Jaffe, Daniel T. (Department of Astronomy, the University of Texas) ;
  • Nguyen-Luong, Quang (Korea Astronomy & Space Science institute) ;
  • Tatematsu, Ken'ichi (National Astronomical Observatory of Japan)
  • 발행 : 2017.10.10

초록

NGC 6822 is a dwarf irregular galaxy in the Local Group and it is located in 500 kpc, further than the Large Magellanic Cloud and the Small Magellanic Cloud. Therefore, we can study star-forming processes by local condition in NGC 6822 instead of tidal force of the Galactic gravitational field. Hubble V is the brightest of several H II complexes in this galaxy. We observed Hubble V by using IGRINS attached on the 2.7 m telescope at the McDonald Observatory in Texas, US in May 2016. We performed a spectral mapping of $15^{{\prime}{\prime}}{\times} 7^{{\prime}{\prime}}$area on H and K bands, and detected emission lines of bright $Br{\gamma}\;{\lambda}2.1661{\mu}m$ and weak He I ${\lambda}2.0587{\mu}m$. Molecular hydrogen lines of 1-0S(1) ${\lambda}2.1218{\mu}m$, 2-1 S(1) ${\lambda}2.2477{\mu}m$, and 1-0 S(0) ${\lambda}2.2227{\mu}m$ was also detected. These emission lines show the structure of an ionized core and excited surface of clouds by far-ultraviolet photons, photodissociation region (PDR). We present three-dimensional maps of emission line distributions through multi slit scanning data and compare these results with the previous study. This presentation shows the physical structure of the star-forming regions and we discuss a PDR model and an evolution of Hubble V complex.

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