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        검색결과 2

        1.
        2005.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We searched for X-ray emission from the 665 galaxies inside and towards the nearby voids by analyzing the ROSAT All-Sky Survey (RASS) data as well as the ROSAT pointed observations (PSPC). As a result we have detected six X-ray emitting galaxies. Two (UGC 10205 and NGC 7509) are in the high density region in the local void, three (UGC 749, MCG +11-10-073, and Mrk 464) are towards the nearby voids, and UGC 32 is located in the low density region. We carried out a timing analysis for both Mrk 464 and UGC 32, and a spectral analysis for Mrk 464. The light curve of Mrk 464 shows the possibility of periodic X-ray flux variation and UGC 32 shows weak, but rapid variation.
        4,000원
        2.
        2001.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present the results of optical differential photometry of five blazars [PKS0219+428 (3C66A), PKS 0235+164 (AO 0235+16), H0414+019, PKS 0851+202 (OJ 287) and QSO 1807+698 (3C 371)] that were observed on 7 nights between November 05, 1997 and December 29, 1998, using the B and the V band filters. We have detected microvariations in four blazars (3C66A, AO 0235+16, H04l4+019, and OJ 287). In addition, the light curve of AO 0235+16 has displayed a mini-flare when the brightness of this source was decreasing. Night-to-night variations have also been detected in 3C66A, H04l4+019, and OJ 287. The results of our observations are discussed in the framework of accretion disk phenomena (magnetic flares or hot spots in accretion disks) and jet phenomena (plasma instabilities in jets).
        4,000원