• 제목/요약/키워드: PKAS

검색결과 583건 처리시간 0.023초

COSMIC DUST AND COSMOLOGY

  • PREVENSLIK, THOMAS V.
    • 천문학논총
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    • 제30권2호
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    • pp.327-330
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    • 2015
  • Cosmology considers the Hubble redshift of galaxy light by the Doppler effect as proof the Universe has been expanding since the Big Bang. However, cosmic dust that permeates the Universe also redshifts galaxy light that if not corrected over-predicts the velocities of all astronomical measurements inferred by the Doppler effect. Hubble redshifts corrected for cosmic dust suggest the Universe may not be expanding, the consequence of which may allow the outstanding problems in cosmology to possibly be resolved by Newtonian mechanics.

THE LONG BASELINE ARRAY

  • EDWARDS, PHILIP G.;PHILLIPS, CHRIS
    • 천문학논총
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    • 제30권2호
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    • pp.659-661
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    • 2015
  • The Long Baseline Array is an array of radio telescopes using the technique of Very Long Baseline Interferometry to achieve milli-arcsecond-scale angular resolution. The core telescopes are located in Australia, with telescopes in New Zealand and South Africa also participating regularly. In this paper the capabilities of the Long Baseline Array are described, and examples of the science undertaken with the array are given.

PROGRESS REPORT: INVESTIGATION OF THE MORPHOLOGY OF CLUSTER GALAXIES

  • OH, SEULHEE;YI, SUKYOUNG K.
    • 천문학논총
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    • 제30권2호
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    • pp.529-530
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    • 2015
  • We investigated the galaxy morphology of 6 Abell clusters at z = 0.0784 - 0.145 based on deep images obtained using MegaCam on the CFHT. For hundreds of galaxies in our data, we classified their morphology based on criteria related to secular or merger related evolution. We found that the morphological mixture of galaxies varies considerably from cluster to cluster. This article contains a general description of our deep imaging campaign and preliminary results for galaxy morphologies in cluster environments.

LOCAL ENVIRONMENTAL EFFECTS ON AGN ACTIVITIES

  • KIM, JAEMIN;YI, SUKYOUNG K.
    • 천문학논총
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    • 제30권2호
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    • pp.451-452
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    • 2015
  • We performed statistical analysis for a nearby (0.01 < z < 0.05) volume limited ($M_r$ < -19) sample of galaxies via visual inspection and the definition of galaxy pair systems based on the Sloan Digital Sky Survey Data Release 7 in order to confirm the effects of galaxy interaction on AGN activities. We found that local environmental effects such as galaxy interaction have an influence on the enhancement of the frequency and the strength of the AGN activity. This article is the summary of the paper which will be submitted soon.

TEACHING ASTRONOMY - USING HYBRID TEXTBOOKS TO COMBAT ACADEMIC E-CHEATING

  • MONTGOMERY, M.M.
    • 천문학논총
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    • 제30권2호
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    • pp.737-739
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    • 2015
  • To accommodate today's higher education student, fewer textbooks are printed and more are becoming digital. Keeping with the modern era, hybrid versions of textbooks have all end-of-chapter assessment content moved to digital learning systems such as MindTap$^{TM}$ by Cengage $Learning^{(R)}$. In this work, we introduce new pedagogical strategies to combat academic e-cheating, specifically cheating on assessments given in online astronomy courses. The strategies we present in this work are employed in Horizons: Exploring the Universe, Hybrid, 13th Edition, and Universe, Hybrid, 8th Edition, by Seeds, Backman, and Montgomery.

ACTIVITY OF IRSF FOR 14 YEARS

  • SATO, SHUJI;NAGAYAMA, TAKAHIRO
    • 천문학논총
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    • 제30권2호
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    • pp.663-664
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    • 2015
  • The activities of IRSF, a 1.4m infrared telescope operated under collaboration between Japan and South Africa, are presented briefly. The dedicated instrument, SIRIUS, which sits at the Cassegrain, has produced unique and prosperous science for 14 years. My talk involves; ${\circ}$ concept of construction and operation, ${\circ}$ publications and education, ${\circ}$ the successive upgrading of the instrument, and ${\circ}$ future plans.

ASTRONOMY FOR DEVELOPMENT; APPROACHES IN ASIA

  • USUDA-SATO, KUMIKO;TOMITA, AKIHIKO
    • 천문학논총
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    • 제30권2호
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    • pp.731-733
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    • 2015
  • As task force members, we present the International Astronomical Union (IAU) Office of Astronomy for Development (OAD) and its task forces. Each task force calls for proposals every year and reviews the submitted proposals. From the point of view of "Astronomy for a Better World", the vision of the OAD, our aim is to reach diverse people including those such as the visually impaired. Our efforts meet one of the goals of the OAD and some OAD-funded projects.

VLBI MEASUREMENT OF WEAK SOURCES WITH IMPROVED SENSITIVITY

  • SHU, FENGCHUN;JIANG, WU
    • 천문학논총
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    • 제30권2호
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    • pp.651-653
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    • 2015
  • Compared with traditional analog system, the Chinese VLBI Data Acquisition System (CDAS) is a digital one with better bandpass and wider bandwidth which allow weaker sources to be detected and measured by VLBI techniques. After optimizing and verifying the performance of CDAS in wide bandwidth observing mode, we performed an experiment by observing 85 weak sources along the ecliptic with Chinese VLBI stations located at Shanghai, Kunming and Urumqi. The capability of CDAS has been demonstrated for the detection of weak sources with improved sensitivity.

INTRODUCING tlc_s05: A CODE TO FIT CEPHEID JHK BAND LIGHT CURVES USING A TEMPLATE APPROACH

  • NGEOW, CHOW-CHOONG;KANBUR, SHASHI M.
    • 천문학논총
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    • 제30권2호
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    • pp.225-227
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    • 2015
  • We introduce a code called tlc_s05, to fit sparsely sampled JHK band Cepheid light curve data with template light curves to derive the mean magnitude. A brief description of the code is provided here. We tested the performance of the code in deriving the mean JHK band magnitudes using simulations, and we found that it is better to observe more than four evenly spaced data points per light curve, which permits tlc_s05 to derive accurate mean magnitudes for Cepheid JHK band light curves.

PERIODIC VARIABILITY OF RY Tau

  • ISMAILOV, NARIMAN Z.;ADIGEZALZADE, H.N.;BAHADDINOVA, G.R.
    • 천문학논총
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    • 제30권2호
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    • pp.229-230
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    • 2015
  • The results of spectral studies of the CTTS type young star RY Tau with spectrograms of the ultraviolet and the visual ranges are presented. We show the first detection of periodic variability of the emission line intensities in UV and visual ranges with a period of 23 days.