한국지구과학회지 제41권 제3호 (p.211-221)

적색편이 z<0.05의 외부고리 은하에 대한 연구

A Study of Outer-ring Galaxies within z<0.05
키워드 :
SDSS DR7,outer-ring galaxy,photometry,galactic environment

목차

Abstract
요 약
서 론
연구 방법 및 절차
   데이터 선정
   자료 처리
   연구 결과
   등광도지도
   광도윤곽, 타원율, 위치각
분석 및 논의
   외부고리 은하의 개수 비율
   외부고리 은하의 환경
   5-band 광도 윤곽(luminosity profile)
결론 및 토의
References

초록

This study classified outer-ring galaxies using 25,308 galaxies within z=0.05 from the SDSS DR7, which are larger than Rpet>6 arcsec and whose minor-to-major axis ratio (b/a)<0.6. We selected 531 galaxies that have ring-like structures by visual inspection of the color images of 25,308 galaxies; these galaxies with ring-like structures served as a primary sample from which we selected 90 outer-ring galaxies. The final sample of 69 outer-ring galaxies was selected by examining the photometric properties of the candidate galaxies. Their properties were determined by conducting surface photometry on their u, g, r, i, and z images. The frequency of the outer-ring galaxies was found to be 0.3% of the local galaxies. We examined the environment of the outer-ring galaxies using two measures of environment, namely, the projected distance to the nearest-neighbor galaxy and the local background density. We did not observe any notable difference between outer-ring and other galactic environments.