천문학회지 (Journal of The Korean Astronomical Society)

  • 제49권6호
  • /
  • Pages.255-259
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  • 2016
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  • 1225-4614(pISSN)
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  • 2288-890X(eISSN)
한국천문학회 (The Korean Astronomical Society)
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THE FRACTAL DIMENSION OF THE 𝜌 OPHIUCUS MOLECULAR CLOUD COMPLEX

  • Lee, Yongung (Korea Astronomy and Space Science Institute) ;
  • Li, Di (National Astronomical Observatories, Department of Radio Astronomy) ;
  • Kim, Y.S. (Korea Astronomy and Space Science Institute) ;
  • Jung, J.H. (Korea Astronomy and Space Science Institute) ;
  • Kang, H.W. (Korea Astronomy and Space Science Institute) ;
  • Lee, C.H. (Korea Astronomy and Space Science Institute) ;
  • Yim, I.S. (Korea Astronomy and Space Science Institute) ;
  • Kim, H.G. (Korea Astronomy and Space Science Institute)
  • 투고 : 2016.11.10
  • 심사 : 2016.12.06
  • 발행 : 2016.12.31
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초록

We estimate the fractal dimension of the ${\rho}$ Ophiuchus Molecular Cloud Complex, associated with star forming regions. We selected a cube (${\upsilon}$, l, b) database, obtained with J = 1-0 transition lines of $^{12}CO$ and $^{13}CO$ at a resolution of 22" using a multibeam receiver system on the 14-m telescope of the Five College Radio Astronomy Observatory. Using a code developed within IRAF, we identified slice-clouds with two threshold temperatures to estimate the fractal dimension. With threshold temperatures of 2.25 K ($3{\sigma}$) and 3.75 K ($5{\sigma}$), the fractal dimension of the target cloud is estimated to be D = 1.52-1.54, where $P{\propto}A^{D/2}$, which is larger than previous results. We suggest that the sampling rate (spatial resolution) of observed data must be an important parameter when estimating the fractal dimension, and that narrower or wider dispersion around an arbitrary fit line and the intercepts at NP = 100 should be checked whether they relate to firms noise level or characteristic structure of the target cloud. This issue could be investigated by analysing several high resolution databases with different quality (low or moderate sensitivity).

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참고문헌

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