• Title/Summary/Keyword: PKAS

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THE PARKES PULSAR TIMING ARRAY PROJECT

  • HOBBS, GEORGE
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.577-581
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    • 2015
  • The main goals of the Parkes Pulsar Timing Array (PPTA) project are to 1) detect ultra-low-frequency gravitational waves, 2) improve the solar system planetary ephemeris and 3) provide a long-term, stable time standard. In this paper, we highlight the main results from the project so far and discuss our expectations for the future.

LARGE INTERNATIONAL PROJECTS AT THE NATIONAL ASTRONOMICAL OBSERVATORY OF JAPAN

  • HAYASHI, MASAHIKO
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.617-620
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    • 2015
  • This paper presents an overview of the large international projects in which the National Astronomical Observatory of Japan is involved, namely, the Subaru Telescope, Atacama Large Millimeter/submillimeter Array, and the Thirty Meter Telescope. The last section provides a brief historical view of the international collaboration in East Asia regions over the last 20 years.

THE AUSTRALIA TELESCOPE NATIONAL FACILITY

  • EDWARDS, PHILIP G.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.655-657
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    • 2015
  • The Australia Telescope National Facility (ATNF) consists of the Parkes and Mopra radio telescopes, and the Australia Telescope Compact Array, with the first elements of the wide-field Australian Square Kilometer Array Pathfinder (ASKAP), currently being commissioned. The capabilities of these facilities are described.

CONSTRUCTION OF KOREAN ASTRONOMICAL JOURNAL DB (국내 천문학 논문 검색 DB 구축)

  • Sung, Hyun-Il;Kim, Soon-Wook;Yim, In-Sung;Sang, Jian
    • Publications of The Korean Astronomical Society
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    • v.21 no.2
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    • pp.113-119
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    • 2006
  • The Korean Astronomical Data Center(KADC) in Korea Astronomy and Space Science Institute(KASI) has developed a database of astronomical journals published by the Korean Astronomical Society and the Korean Space Science Society. It consists of all bibliographic records of the Journal of the Korean Astronomical Society(JKAS), Publication of the Korean Astronomical Society(PKAS), and Journal of Astronomy & Space Sciences(JASS). The KADC provides useful search functions in the search page such as search criterion of bibcode, publication date, author names, title words, or abstract words. The journal name is one of the search criterion in which more than one journal can be designated at the same time. The criterion of author name is provided bilingually: English or Korean. The abstract and full text can be downloaded as PDF files. It is also possible to search papers related to a specific research topic published in Korean astronomical journals, provided by the KADC, which often cannot be found the worldwide, Astrophysics Data System(ADS) services. The KADC will become basic infrastructure for the systematic construction of bibliographic records, and hence, make the society of Korean astronomers more interactive and collaborative.

THREE-DIMENSIONAL SIMULATION OF A ROTATING CORE-COLLAPSE SUPERNOVA

  • NAKAMURA, KO;KURODA, TAKAMI;TAKIWAKI, TOMOYA;KOTAKE, KEI
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.481-483
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    • 2015
  • Multi-dimensionality in the inner working of core-collapse supernovae has long been considered one of the most important ingredients to understand the explosion mechanism. We perform a series of numerical experiments to explore how rotation impacts the 3-dimensional hydrodynamics of core-collapse supernova. We employ a light-bulb scheme to trigger explosions and a three-species neutrino leakage scheme to treat deleptonization effects and neutrino losses from the neutron star interior. We find that the rotation can help the onset of neutrino-driven explosions for models in which the initial angular momentum is matched to that obtained from recent stellar evolutionary calculations (${\sim}0.3-3rad\;s^{-1}$ at the center). For models with larger initial angular momenta, a shock surface deforms to be oblate due to larger centrifugal force. This makes a gain region, in which matter gains energy from neutrinos, more concentrated around the equatorial plane. As a result, the preferred direction of the explosion in 3-dimensional rotating models is perpendicular to the spin axis, which is in sharp contrast to the polar explosions around the axis that are often obtained from 2-dimensional simulations.

THE AKARI DEEP FIELD SOUTH: A NEW HOME FOR MULTIWAVELENGTH EXTRAGALACTIC ASTRONOMY

  • Clements, David L.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.135-140
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    • 2012
  • The importance of multiwavelength astronomical surveys is discussed in the context of galaxy evolution. The AKARI Deep Field South (ADF-S) is a new, well placed survey field that is already the subject of studies at a wide range of wavelengths. A number of ADF-S observational programmes are discussed and the prospects for the ADF-S as a future resource for extragalactic astronomy is explored.

A MULTICOLOR STAR-GALAXY SEPARATION FROM THE NIR AND MIR AKARI DATA

  • Solarz, A.;Pollo, A.;Takeuchi, T.T.;Pepiak, A.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.151-152
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    • 2012
  • We present the method of star/galaxy separation based on the support vector machines (SVM) in the data from the AKARI North Ecliptic Pole (NEP) Deep survey collected through nine AKARI / IRC bands from 2 to $24{\mu}m$, with a classification accuracy of 93 %.

FAR INFRARED AND SUBMILLIMETRE SURVEYS: FROM IRAS TO AKARI, HERSCHEL AND PLANCK

  • Rowan-Robinson, Michael;Wang, Lingyu
    • Publications of The Korean Astronomical Society
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    • v.32 no.1
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    • pp.293-297
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    • 2017
  • We discuss a new IRAS Faint Source Catalog galaxy redshift catalogue (RIFSCz) which incorporates data from Galex, SDSS, 2MASS, WISE, AKARI and Planck. AKARI fluxes are consistent with photometry from other far infrared and submillimetre missions provided an aperture correction is applied. Results from the Hermes-SWIRE survey in Lockman are also discussed briefly, and the strong contrast between the galaxy populations selected at 60 and $500{\mu}m$ is summarized.

COSMOLOGICAL APPLICATIONS OF MULTIPLE-IMAGE GRAVITATIONALLY LENSED QUASARS (다상 준항성 중력렌즈의 우주론적 응용)

  • Park, Myeong-Gu
    • Publications of The Korean Astronomical Society
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    • v.22 no.1
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    • pp.1-20
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    • 2007
  • Quasars at cosmological distances can be gravitationally lensed by galaxies into two or more images. The probability of this lensing and the angular separation between the images depend on the geometry and the expansion history of the universe as well as the lensing galaxies. The time delay between lensed images is also a direct indicator of the size of the universe. I review these cosmological applications of multiple-image gravitationally lensed quasars to determine or constrain the cosmological parameters.

CMBR FLUCTUATIONS IN THE BIANCHI TYPE I SPACETIME: THE EFFECTS OF GRAVITATIONAL WAVES (비앙키 I 형 시공간 속의 CMBR 흔들림: 중력파의 영향)

  • Song, D.J.
    • Publications of The Korean Astronomical Society
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    • v.18 no.1
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    • pp.1-9
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    • 2003
  • In the framework of linear perturbation theory and linear approximation of spacetime anisotropy, we investigated the formulae for the CMBR temperature anisotropy and fluctuation spectrum which have their origin in the primordial tensor perturbations of the perturbed Bianchi type I universe model. The resulting formulae were compared with those of the flat Friedmann model.