천문학회보 (The Bulletin of The Korean Astronomical Society)
- 제41권2호
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- Pages.33.1-33.1
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- 2016
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- 1226-2692(pISSN)
Detection of short-term flux variability and intraday variability in polarized emission at millimeter-wavelength from S5 0716+714
- Lee, Jeewon (Korea Astronomy and Space Science Institute) ;
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Sohn, Bong Won
(Korea Astronomy and Space Science Institute) ;
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Byun, Do-Young
(Korea Astronomy and Space Science Institute) ;
- Lee, Jeong Ae (Korea Astronomy and Space Science Institute) ;
- Lee, Sang Sung (Korea Astronomy and Space Science Institute) ;
- Kang, Sincheol (Korea Astronomy and Space Science Institute) ;
- Kim, Sungsoo S. (Korea Astronomy and Space Science Institute)
- 발행 : 2016.10.12
초록
We report detection of short-term flux variability in multi-epoch observations and intraday variability in polarized emission at millimeter-wavelength from S5 0716+714 using Korean VLBI Network (KVN) radio telescopes. Over the whole observation epochs, the source shows significant inter-month variations at K- and Q-band with modulation indices of 19% at K-band and 36% at Q-band. In each epoch, the source shows monotonic flux increase in Epoch 1 and 3, and monotonic flux decrease in Epoch 2 and 4. We found an inverted spectrum with mean spectral indices of -0.57 in Epoch 1 and -0.15 in Epoch. On the contrary, we found relatively steep indices of 0.24 and 0.17 in Epoch 2 and Epoch 4, respectively. In the study of intraday variability of polarization, we found significant variations in the degree of linear polarization at 86 GHz, and in polarization angle at 43 and 86 GHz during ~10 h. The spectrum of the source is quite flat with spectral indices of -0.07 to 0.07 at 22-43 GHz and -0.23 to 0.04 at 43-86 GHz. The measured degree of the linear polarization ranges from 2.3% to 3.3 % at 22 GHz, from 0.9% to 2.2 % at 43 GHz and from 0.4 % to 4.0 % at 86 GHz, yielding prominent variations at 86 GHz over 4-5 h. The linear polarization angle is in the range of 4 to
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