AAS Meeting #193 - Austin, Texas, January 1999
Session 35. The Next Generation Space Telescope
Display, Thursday, January 7, 1999, 9:20am-6:30pm, Exhibits Hall 1

[Previous] | [Session 35] | [Next]

[35.07] An Investigation of the Performance of CCD Stellar Photometry with a 1.5-\mum Diffraction-Limited 8-m Next Generation Space Telescope

K. Mighell (KPNO/NOAO)

I present the results of an investigation of the performance of CCD stellar photometry with a 1.5-\mum diffraction-limited 8-m Next Generation Space Telescope. These simulations used artificial Point Spread Functions for three different 8-m NGST design concepts which were kindly provided by John Krist. Assuming that the 8-m NGST primary mirror has 1/13 wave RMS errors at 1.5 \mum, I demonstrate that 90% of the light from a star falls within an aperture radius of 0.1 arcsec --- the size of one WF pixel of the {\sl{Hubble Space Telescope}} WFPC2 instrument. The three NGST design concepts have nearly identical V\!-band encircled-energy functions; the degradation caused by the differences between the different design concepts is quite negligible when state-of-the-art digital-PSF photometric reduction software is used to analyze uncrowded stellar fields. All the V\!-band PSFs used in these simulations were sampled at 0.0064 arcsec pixel-1 which is the critical V\!-band sampling rate of a perfect 0.5-\mum diffraction-limited 8-m NGST. Better photometric performance for all three NGST design concepts could be obtained by using larger CCD pixels: a pixel size of ~0.013 (\approx 2\times0.0064) arcsec pixel-1 should provide an optimal pixel sampling when the 8-m primary mirror is diffraction-limited at 1.5 \mum.

If you would like more information about this abstract, please follow the link to http://www.noao.edu/noao/staff/mighell/aas193/. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

The author(s) of this abstract have provided an email address for comments about the abstract: mighell@noao.edu

[Previous] | [Session 35] | [Next]