| タイトル | The Hubble Space Telescope Snapshot Survey. III - Further observations in search of gravitationally lensed quasars |
| 著者（英） | Doxsey, R.; Lahav, O.; Maoz, D.; Bahcall, N. A.; Schneider, D. P.; Bahcall, J. N.; Yanny, B. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 1993-01-01 |
| 言語 | eng |
| 内容記述 | We present new HST Snapshot Survey observations of 163 high-luminosity z greater than 1 quasars, bringing the total number observed to date in the survey to 347 quasars. Each exposure was searched for evidence on gravitational lensing. Among the newly observed quasars, six have additional point sources at separations of 2-6 arcsec, but in all six cases ground-based data indicate that gravitational lensing is not involved. No point sources were found at smaller separations. Counting the one new lens candidate the survey has uncovered and the known lenses excluded from the sample, the observed frequency of lensing of quasars by galaxies is 5/351. This frequency is in the range predicted by models with a vanishing cosmological constant, but an order of magnitude lower than expected in models strongly dominated by a cosmological constant. |
| NASA分類 | ASTROPHYSICS |
| レポートNO | 93A21531 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/321066 |
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