• Title/Summary/Keyword: Astronomy

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대덕전파천문대 레이돔 교체 (New Radome Installation for the TRAO Radio Telescope)

  • Lee, Changhoon;Jung, Jae Hoon;Kang, HyunWoo;Je, Do-Keung;Lee, Youngung;Jung, Il-Gyo;Kim, Young Sik;Lee, Chang Won;Kim, Hyun-Goo
    • 천문학회보
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    • 제42권1호
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    • pp.33.4-34
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    • 2017
  • 전파망원경 레이돔은 14미터 우주전파망원경을 외부 환경(눈, 비, 바람, 햇빛)으로 부터 보호하여 효율적인 우주전파 관측연구를 수행하는데 필수적인 연구시설이다. 현재 사용 중인 대덕전파천문대 레이돔은 1985년에 설치되어 30년째 사용 중이다. 노후화로 인해 누수가 있으며, 겨울철에는 내부에 빙결이 발생하며, 유지보수가 어려운 상황이다. 본 발표에서는 2016년 12월말부터 2017년 2월 초까지 이루어진 레이돔의 교체과정과 기존 레이돔과 교체된 레이돔의 성능 등을 발표한다.

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GECKO Optical Follow-up Observation of Three Binary Black Hole Merger Events

  • Kim, Joonho;Im, Myungshin;Paek, Gregory S.H.;Lee, Chung-Uk;Kim, Seung-Lee;Chang, Seo-Won;Choi, Changsu;Hwang, Sungyong;Kang, Wonseok;Kim, Sophia;Kim, Taewoo;Lee, Hyung Mok;Lim, Gu;Seo, Jinguk;Sung, Hyun-Il
    • 천문학회보
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    • 제46권1호
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    • pp.53.3-54
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    • 2021
  • We present optical follow-up observation results of three binary black hole merger (BBH) events, GW190408 181802, GW190412, and GW190503 185404, which were detected by the Advanced Ligo and Virgo gravitational wave (GW) detectors. Electromagnetic (EM) counterparts are generally not expected for BBH merger events, however, some theoretical models suggest that EM counterparts of BBH can possibly arise in special environments. To identify EM counterparts of the three BBH merger events, we observed high-credibility regions of the sky with telescopes of the Gravitational-wave EM Counterpart Korean Observatory (GECKO), including the Korea Microlensing Telescope Network (KMTNet). Our observation started as soon as 100 minutes after the GW event alert and covered roughly 29 - 63 deg2 for each event with a depth of 22.5 mag in R-band within hours of observation. No plausible EM counterparts were found for these events. Our result gives a great promise for the GECKO facilities to find EM counterparts within few hours from GW detection in future GW observation runs.

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Thermal Analysis of MIRIS Space Observation Camera for Verification of Passive Cooling

  • Lee, Duk-Hang;Han, Won-Yong;Moon, Bong-Kon;Park, Young-Sik;Jeong, Woong-Seob;Park, Kwi-Jong;Lee, Dae-Hee;Pyo, Jeong-Hyun;Kim, Il-Joong;Kim, Min-Gyu;Matsumoto, Toshio
    • Journal of Astronomy and Space Sciences
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    • 제29권3호
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    • pp.305-313
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    • 2012
  • We conducted thermal analyses and cooling tests of the space observation camera (SOC) of the multi-purpose infrared imaging system (MIRIS) to verify passive cooling. The thermal analyses were conducted with NX 7.0 TMG for two cases of attitude of the MIRIS: for the worst hot case and normal case. Through the thermal analyses of the flight model, it was found that even in the worst case the telescope could be cooled to less than $206^{\circ}K$. This is similar to the results of the passive cooling test (${\sim}200.2^{\circ}K$). For the normal attitude case of the analysis, on the other hand, the SOC telescope was cooled to about $160^{\circ}K$ in 10 days. Based on the results of these analyses and the test, it was determined that the telescope of the MIRIS SOC could be successfully cooled to below $200^{\circ}K$ with passive cooling. The SOC is, therefore, expected to have optimal performance under cooled conditions in orbit.

Testing delayed AGN feedback using star formation rate measurements by SED fitting with JCMT/SCUBA-2 data

  • Kim, Changseok;Jadhav, Yashashree;Woo, Jong-Hak;Chung, Aeree;Baek, Junhyun;Lee, Jeong Ae;Shin, Jaejin;Hwang, Ho Seong;Luo, Rongxin;Son, Donghoon;Kim, Hyungi;Woo, Hyuk
    • 천문학회보
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    • 제46권2호
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    • pp.40.2-40.2
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    • 2021
  • The impact of AGN on star formation is one of the main questions in AGN-galaxy coevolution studies. However, direct evidence of AGN feedback is still rare. One of the main obstacles is that various star formation rate (SFR) indicators are contaminated by AGN contribution. We present IR-based SFR measurements of a sample of 52 local (z<0.3) AGNs, which were selected based on kinematical properties of ionized gas outflows, using SED analysis with JCMT/SCUBA-2 data. First, we will compare IR-based SFR with other SFR indicators to check the reliability of the SFR indicators. Second, we will discuss the contribution of Mid-IR emission from hot dust of AGN torus by comparing SED fitting results with and without including AGN dust component. Finally, we will report the correlation between specific SFR (sSFR) and AGN activity (e.g., outflow strength or Eddington ratio) as evidence of no instantaneous feedback and discuss the implications of these results

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Design of KAO Near Infrared Camera System on the SOAO 0.6m Telescope

  • Jin Ho;Park Soojong;Yuk In-Soo;Lee Sungho;Moon Bongkon;Han Jeong-Yeol;Seon Kwag-Il;Kang Jina;Kong Kyung-Nam;Nam Wook-Won;Lee Dae-Hee
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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    • pp.70-70
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    • 2004
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