Instrument: Gemini North Acquisition Camera. The CCD in the Acquisition Camera has 1024 x 1024 pixels.
Pixel scale: 0.12 arcsec per pixel (Detector pixels)
Field of view: 115 arcsec x 103 arcsec
Filter: V-band
Exposure time: 12 x 1 second
Resolution: 0.6 arcsec FWHM
Processing: The images were dark subtracted. No
flat-field correction was done. The images were then registered and co-added.
Technical information - Infrared Image
Instrument: The observations were obtained with
the University of Hawaii Adaptive Optics System (Hokupa'a) with the infrared
camera QUIRC. Hokupa'a is a 36-element curvature-sensing AO system. The
Insitute
for Astronomy, University of Hawaii, Adaptive
Optics Group has more information about the AO system. The detector
in QUIRC is a Rockwell 1024 x 1024 pixel HgCdTe "HAWAII" array sensitive
to 2.5 microns. A description
of QUIRC is available from the Insitute for Astronomy.
Pixel scale: 0.01974 arcsec per pixel (Detector
pixels)
Field of view: 20.4 arcsec x 25.5 arcsec
Information about filters, exposure time and resolution:
Filter | Exposure time | Resolution (FWHM) |
K-band (2.2 µm broad band) | 23 min 35 sec | 0.09 arcsec |
The images were taken as individual exposures with exposure times of 10 seconds or 15 seconds. The limiting magnitude is approximately K=21.3 mag (5sigma detection).
Processing: The images were sky-subtracted using sky images obtained before and after the observations. Then the images were registered and co-added.
The images were then processed with a filtering method that suppresses the PSF halo characteristics of partially compensated AO images. This consists in a simple, linear filtering of the image in the Fourier space, based on an empirical analysis of the properties of AO compensated images. It does not affect the core of the PSF, the airy rings nor possible PSF artifacts. To first order, the resolution is therefore the same as in the unfiltered images.