http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
OPTICAL-INFRARED AND HIGH-ENERGY ASTRONOMY COLLABORATION AT HIROSHIMA ASTROPHYSICAL SCIENCE CENTER
UEMURA, MAKOTO,YOSHIDA, MICHITOSHI,KAWABATA, KOJI S.,MIZUNO, TSUNEFUMI,TANAKA, YASUYUKI T.,AKITAYA, HIROSHI,UTSUMI, YOUSUKE,MORITANI, YUKI,ITOH, RYOSUKE,FUKAZAWA, YASUSHI,TAKAHASHI, HIROMITSU,OHNO, MA The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2
The Hiroshima Astrophysical Science Center (HASC) was founded in 2004 at Hiroshima University, Japan. The main mission of this institute is the observational study of various transient objects including gamma-ray bursts, supernovae, novae, cataclysmic variables, and active galactic nuclei by means of multi-wavelength observations. HASC consists of three divisions; the optical-infrared astronomy division, high-energy astronomy division, and theoretical astronomy division. HASC is operating the 1.5m optical-infrared telescope Kanata, which is dedicated to follow-up and monitoring observations of transient objects. The high-energy division is the key operation center for the Fermi gamma-ray space telescope. HASC and the high-energy astronomy group in the department of physical science at Hiroshima University are closely collaborating with each other to promote multi-wavelength time-domain astronomy. We report the recent activities of HASC and some science topics pursued by this multi-wavelength collaboration.
Optical and Near-infrared Polarimetry of Non-periodic Comet C/2013 US10 (Catalina)
Kwon, Yuna Grace,Ishiguro, Masateru,Kuroda, Daisuke,Hanayama, Hidekazu,Kawabata, Koji S.,Akitaya, Hiroshi,Nakaoka, Tatsuya,Itoh, Ryosuke,Toda, Hiroyuki,Yanagisawa, Kenshi,Lee, Myung Gyoon,Ohta, Kouji American Institute of Physics 2017 The Astronomical journal Vol.154 No.4
<P>We present an optical and near-infrared (hereafter NIR) polarimetric study of a comet C/2013 US10 (Catalina) observed on UT 2015 December 17-18 at phase angles of alpha - 52 degrees.1-53 degrees.1. Additionally, we obtained an optical spectrum and multi-band images to examine the influence of gas emission. We find that the observed optical signals are significantly influenced by gas emission; that is, the gas-to-total intensity ratio varies from 5 to 30% in the RC and 3%-18% in the I-C bands, depending on the position in the coma. We derive the 'gas-free dust polarization degrees' of 13.8% +/- 1.0% in the RC and 12.5% +/- 1.1% in the IC bands and a gray polarimetric color, i.e., -8.7% +/- 9.9% mu m(-1) in optical and 1.6% +/- 0.9% mu m(-1) in NIR. The increments of polarization obtained from the gas correction show that the polarimetric properties of the dust in this low-polarization comet are not different from those in high-polarization comets. In this process, the cometocentric distance dependence of polarization has disappeared. We also find that the RC-band polarization degree of the southeast dust tail, which consists of large dust particles (100 mu m(-1) mm), is similar to that in the outer coma where small and large ones are mixed. Our study confirms that the dichotomy of cometary polarization does not result from the difference of dust properties, but from depolarizing gas contamination. This conclusion can provide a strong support for similarity in origin of comets.</P>
Polarimetric Observation of (3200) Phaethon, in Preparation for the Upcoming DESTINY+ Space Mission
Jooyeon Geem,Masateru Ishiguro,Jun Takahashi,Hiroshi Akitaya,Koji S. Kawabata,Tatsuya Nakaoka,Ryo Imazawa,Fumiki Mori,Daisuke Kuroda,Sunao Hasegawa,Fumi Yoshida,Ko Ishibashi,Tomoko Arai,Tomohiko Sekig 한국천문학회 2022 天文學會報 Vol.47 No.1