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        검색결과 2

        1.
        2015.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We study the radio properties at 1.4 GHz of Seyfert galaxies with strong forbidden highionization lines (FHILs), selected from the Sloan Digital Sky Survey – a large-sized sample containing nearly equal proportion of diverse range of Seyfert galaxies showing similar redshift distributions compiled by Gelbord et al. (2009) using the Very Large Array survey images. The radio detection rate is low, 49%, which is lower than the detection rate of several other known Seyfert galaxy samples. These galaxies show low star formation rates and the radio emission is dominated by the active nucleus with ≤10% contribution from thermal emission, and possibly, none show evidence for relativistic beaming. The radio detection rate, distributions of radio power, and correlations between radio power and line luminosities or X-ray luminosity for narrow-line Seyfert 1 (NLS1), Seyfert 1 and Seyfert 2 galaxies are consistent with the predictions of the unified scheme hypothesis. Using correlation between radio and [O III]  5007°A luminosities, we show that ∼8% sample sources are radio-intermediate and the remaining are radio-quiet. There is possibly an ionization stratification associated with clouds on scales of 0.1–1.0 kpc, which have large optical depths at 1.4GHz, and it seems these clouds are responsible for free–free absorption of radio emission from the core; hence, leading to low radio detection rate for these FHIL-emitting Seyfert galaxies.
        4,600원
        2.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recognition of the role of radio galaxies in the universe has been increasing in recent years. Their colossal energy output over huge volumes is now widely believed to play a key role not only in the formation of galaxies and their supermassive black holes, but also in the evolution of clusters of galaxies and, possibly, the cosmic web itself. In this regard, we need to understand the in ation of radio bubbles in the hot gas atmospheres of clusters and the importance of the role that radio galaxies play in the overall energy budget of the intracluster medium. Here, we present results from X-ray and radio band observations of the hot gas atmospheres of powerful, nearby radio galaxies in poor clusters.
        4,000원