천문학회지 (Journal of The Korean Astronomical Society)

  • 제52권6호
  • /
  • Pages.227-233
  • /
  • 2019
  • /
  • 1225-4614(pISSN)
  • /
  • 2288-890X(eISSN)
한국천문학회 (The Korean Astronomical Society)
권호 표지
DOI QR코드

DOI QR Code

PERFORMANCE OF THE TRAO 13.7-M TELESCOPE WITH NEW SYSTEMS

  • 투고 : 2019.09.27
  • 심사 : 2019.12.05
  • 발행 : 2019.12.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

We report the performance of the 13.7-meter Taeduk Radio Astronomy Observatory (TRAO) radio telescope. The telescope has been equipped with a new receiver, SEQUOIA-TRAO, a new backend system, FFT2G, and a new VxWorks operating system. The receiver system features a 16-pixel focal plane array using high-performance MMIC preamplifiers; it shows very low system noise levels, with system noise temperatures from 150 K to 450 K at frequencies from 86 to 115 GHz. With the new backend system, we can simultaneously obtain 32 spectra, each with a velocity coverage of 163 km s-1 and a resolution of 0.04 km s-1 at 115 GHz. The new operating system, VxWorks, has successfully handled the LMTMC-TRAO observing software. The main observing method is the on-the-fly (OTF) mapping mode; a position-switching mode is available for small-area observations. Remote observing is provided. The antenna surface has been newly adjusted using digital photogrammetry, achieving a rms surface accuracy better than 130 ㎛. The pointing uncertainty is found to be less than 5" over the entire sky. We tested the new receiver system with multi-frequency observations in OTF mode. The aperture efficiencies are 43±1%, 42±1%, 37±1%, and 33±1%, the beam efficiencies are 45±2%, 48±2%, 46±2%, and 41±2% at 86, 98, 110, and 115 GHz, respectively.

키워드

참고문헌

  1. Baars, J. W. M. 1973, The Measurement of Large Antennas with Cosmic Radio Sources, IEEE Trans. Antennas Propag., 21, 461 https://doi.org/10.1109/TAP.1973.1140521
  2. Balanis, C. A. 1989, Advanced Engineering Electromagnetics (Hoboken: John Wiley & Sons)
  3. Cho, S.-H., Chung, H.-S., Kim, H.-R., et al. 1998, Observations of SiO (v = 0, 1, 2) J = 3-2 and J = 2-1 Emission in Late-Type Stars, ApJS, 115, 277 https://doi.org/10.1086/313083
  4. Cho, S.-H., Lee, C. W., & Park, Y.-S. 2007, First Detection of the SiO (v = 3, J = 2 - 1) Maser Emission from ${\chi}$ Cygni, ApJ, 657, 482 https://doi.org/10.1086/510837
  5. Erickson, N. R., Goldsmith, P. F., Novak, G., et al. 1992, A 15 Element Focal Plane Array for 100 GHz, IEEE Trans. Microw. Theory Tech., 40, 1 https://doi.org/10.1109/22.108317
  6. Erickson, N. R., Grosslein, R. M., Erickson, R. B., &Weinreb, S. 1999, A Cryogenic Focal Plane Array for 85-115 GHz Using MMIC Preamplifiers, IEEE Trans. Microw. Theory Tech. 47, 2212 https://doi.org/10.1109/22.808962
  7. Joiner, J., & Steffes, P. G. 1991, Modeling of Jupiter's Millimeter Wave Emission Utilizing Laboratory Measurements of Ammonia ($NH_3$) Opacity, JGR, 96, 17
  8. Koo, B.-C., Park, Y.-S., Hong, S. S., et al. 2003, Performance of the SRAO 6-Meter Radio Telescope, JKAS, 36, 43
  9. Koo, B.-C., Rho, J., Reach, W. T., et al. 2001, Shocked Molecular Gas in the Supernova Remnant HB 21, ApJ, 552, 175 https://doi.org/10.1086/320442
  10. Ladd, N., Purcell, C., Wong, T., et al. 2005, Beam Size, Shape and Efficiencies for the ATNF Mopra Radio Telescope at 86-115 GHz, PASA, 22, 62 https://doi.org/10.1071/AS04068
  11. Lee, C., Jung, J. H., Kang, H. W., et al. 2014, Panel Adjustment of the TRAO 13.7-m Antenna Using Photogrammetry, PKAS, 29, 53
  12. Lee, S.-S., Byun, D.-Y., Oh, C. S., et al. 2011, Single-Dish Performance of KVN 21-m Radio Telescopes: Simultaneous Observations at 22 and 43 GHz, PASP, 123, 1398 https://doi.org/10.1086/663326
  13. Lee, Y., Kim, Y. S., Kim, H.-G., et al. 2014, Two Molecular Clouds with Anomalous Velocities in the Galactic Anticenter, JKAS, 47, 319
  14. Loughnane, R. M., Redman, M. P., Thompson, M. A., et al. 2012, Observations of HCN Hyperfine Line Anomalies towards Low- and High-mass Star-forming cores, MNRAS, 420, 1367 https://doi.org/10.1111/j.1365-2966.2011.20121.x
  15. Mangum, J. G., Emerson, D. T., & Greisen, E. W. 2007, The On-The-Fly Imaging Technique, A&A, 474, 679 https://doi.org/10.1051/0004-6361:20077811
  16. Roh, D.-G., & Jung, J. H. 1999, Characteristics of TRAO 14m Radio Telescope (1999), PKAS, 14, 123
  17. Sawada, T., Ikeda, N., Sunada, K., et al. 2008, On-The-Fly Observing System of the Nobeyama 45-m and ASTE 10-m Telescopes, PASJ, 60, 445 https://doi.org/10.1093/pasj/60.3.445
  18. Weiland, J. L., Odegard, N., Hill, R. S., et al. 2011, Seven-year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Planets and Celestial Calibration Sources, ApJS, 192, 19 https://doi.org/10.1088/0067-0049/192/2/19