NEAT QUEST CAMERA ================= Instrument Overview =================== The QUEST camera (Baltay et al. 2007) began operations at Palomar Observatory in June 2003 and replaced the tri-camera. It was designed and constructed at Yale University and consists of 112 CCD chips manufactured by the Sarnoff Corporation. Four rows, or fingers, each contain twenty- eight CCDs. Each CCD is 600 x 2400 with 13 micron square pixels. The pixel scale is 0.87 arc-sec/pixel. The camera covers an area of 4.6 degrees by 3.6 degrees with an effective area of 9.6 square degrees of sky. The central wavelength is 760 nm. During the point-and-track obs ervations used by NEAT, a red (effective wavelength 610 nm) Bessel filter was used. The table below provides a comparison of the QUEST and tri-camera instruments used by NEAT at Palomar Observatory. -------------------------------------------------------------- | Site Pal/Tri-cam Palomar/QUEST | | Dates of Operation: 4/01 - 6/03 6/03 - 4/07 | | Telescope Diameter: 1.2m 1.2m | | f/ratio: 2.50 2.50 | | Camera: 4096 x 4096 x 3 600 x 2400 x 112 | | Pixel Size: 15 x 15 u 13 x 13 u | | Pixel Scale: 1.01'/pix 0.87'/pix | | Cooling: TEC @ ~-30C LN2 @ -120C | | Filter: None 610 nm | | IAU Site Code: 644 644 | | | | Latitude / Longitude: +33deg 21.4' 116deg 51.8'W | | Elevation / Timezone: 1726.3m UTC - 8 | |____________________________________________________________| The fingers are symmetrical about the bore sight. As a result, the pointing centers listed in the 'logs-dot-group' file are the pointing centers of the bore sight; not CCD chip centers. Fingers B and C are offset from the bore sight by +/-30.07 arc-secs (0.5012 deg.) while fingers A and D are offset by +/-90.17 arc-secs (1.5028 deg.), respectively. The twenty-eight CCDs are laid out in a North-South orientation (chips 01-28) from +/-2.25 degrees (chips 01 - 28) from the bore sight pointing coordinates (see table 1, below). Finger CCD D C RA RA DEC 01 -1.5028 -0.5012 2.2483 02 -1.5028 -0.5012 2.0819 03 -1.5028 -0.5012 1.9155 04 -1.5028 -0.5012 1.7490 05 -1.5028 -0.5012 1.5826 06 -1.5028 -0.5012 1.4160 07 -1.5028 -0.5012 1.2495 08 -1.5028 -0.5012 1.0829 09 -1.5028 -0.5012 0.9164 10 -1.5028 -0.5012 0.7498 11 -1.5028 -0.5012 0.5832 12 -1.5028 -0.5012 0.4166 13 -1.5028 -0.5012 0.2499 14 -1.5028 -0.5012 0.0833 15 -1.5028 -0.5012 -0.0833 16 -1.5028 -0.5012 -0.2499 17 -1.5028 -0.5012 -0.4155 18 -1.5028 -0.5012 -0.5832 19 -1.5028 -0.5012 -0.7498 20 -1.5028 -0.5012 -0.9164 21 -1.5028 -0.5012 -1.0829 22 -1.5028 -0.5012 -1.2495 23 -1.5028 -0.5012 -1.4160 24 -1.5028 -0.5012 -1.5826 25 -1.5028 -0.5012 -1.7490 26 -1.5028 -0.5012 -1.9155 27 -1.5028 -0.5012 -2.0819 28 -1.5028 -0.5012 -2.2483 -------------------------------- Table 1: QUEST CCD chip offsets, in degrees, for fingers C and D. Fingers B and A are mirror copies and consist of the same, positive, values (ie finger B's RA offset is 0.5012 degrees and A's RA offset is 1.5028 degrees). Regardless of the camera, each CCD chip read to a unique output file. Filenames are based on the universal start time of the exposure and, if appropriate, identify the specific chip used. Within the QUEST data, the overscan regions are available in the 40 extra rows (rows 600-640). The QUEST images are 3.1 Mb in size, uncompressed, with North towards the left and West downward initially. References ========== Baltay, C., D. Rabinowitz, P. Andrews, A. Bauer, N. Ellman and 15 others, The QUEST Large Area CCD Camera, Publications of the Astronomical Society of the Pacific (PASP) 119, 1278-1294, doi 10.1086/523899, 2007.