내용
사진
사진 업로드
DSS Images Other Images
관련 글
Limits on the short-timescale near-infrared variability of Seyfert 1 nuclei
We present new time-resolved photometric observations and images at 2.2microns of a small sample of X-ray variable Seyfert 1 nuclei. Aftercorrecting for dilution by the host galaxy in the observing aperture, wecompare the fractional variation, over the timescales of theobservations, in the near-infrared (NIR) to that expected in the X rays.We have not detected with confidence any NIR variability on timescalesshort enough to be incompatible with the dust reradiation scenario. Thegalaxy-corrected upper limits which we have obtained for variations onshort timescales, typical of non-thermal processes, imply that the NIRemission is dominated by a slowly varying, presumably reprocessed,component which accounts for no less than 80%-90% of the total.
| Radial-velocity measurements. V - Ground support of the HIPPARCOS satellite observation program
The paper presents data on 1070 radial velocity measurements of starsdistributed in 39 fields measuring 4 deg x 4 deg. The PPO series ofFehrenbach et al. (1987) and Duflot et al. (1990) is continued using theFehrenbach objective prism method.
|
새 글 등록
관련 링크
새 링크 등록
다음 그룹에 속해있음:
|
관측 및 측정 데이터
천체목록:
|
