WFPC2 Instrument Handbook for Cycle 11
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: http://www.stsci.edu/instruments/wfpc2/Wfpc2_hand4/ch7_strategy12.html
Дата изменения: Tue Sep 4 21:44:46 2001 Дата индексирования: Sat Dec 22 19:46:20 2007 Кодировка: Поисковые слова: туманность андромеды |
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| WFPC2 Instrument Handbook for Cycle 11 | |||
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Emission Line Observations of Galaxy Nuclei
Saturation is a common problem for narrow band filter images of galaxy nuclei. Often the surface brightness of the emission line is estimated from ground-based images with 1" resolution; sometimes line fluxes are quoted for apertures several arcseconds in radius. However, at HST resolution, much of this flux may occur in a single unresolved spot at the galaxy nucleus, thus leading to saturated images. Observers should be cautious and consider this possibility when estimating exposure times.
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Space Telescope Science Institute http://www.stsci.edu Voice: (410) 338-1082 help@stsci.edu |
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