4-m BTC MOSAIC IMAGER


Alistair Walker Aug 27 1999 (v1.7)

THE BTC HAS BEEN REPLACED BY THE MOSAIC II IMAGER!!! SEE "NOAO MOSAIC II Imager."

The BTC (Big Throughput Camera), formerly known as LACCD, is a Mosaic Imager built by Tony Tyson (Bell Labs) and Gary Bernstein (U. Michigan). The BTC contains four thinned SITe 2048 CCDs, plus all readout electronics and control computer. A Sparc Ultra 2 computer with fast disk and tape storage is available for data inspection and reduction. The BTC was successfully used at the CTIO 4-m prime focus during visitor runs in May and December 1996, and then became available to all users for semesters I and II of 1997 and 1998. At the end of semester I 1999 the BTC will be replaced with the "NOAO MOSAIC II Imager."

In May 1998 CCDs #1 and #2 were replaced with superior devices. Visit the WWW site

"BIG THROUGHPUT CAMERA"

to see some of the results from the May 1996 observing run. YOU ARE STRONGLY RECOMMENDED TO VISIT

"BTC TECHNICAL INFORMATION."

which contains all information needed by the users of the BTC.

The BTC will be scheduled in two or three block runs per semester, at the 4-m prime focus only. We will only schedule the CTIO prime focus imager, which contains a single SITe 2K CCD, for programs which require filters unavailable in the large size needed for the BTC. Programs satisfied with a 6 x 6 arcmin field and for which better image sampling or U band photometry is important should consider using the 4-m RC focus. Pixel size is 0.16 arcsec with a SITe 2K CCD, and the U band throughput is double that of the prime focus. The information on these WWW pages should help you decide whether or not the BTC will be advantageous for your 4-m imaging program. Please contact me (awalker@noao.edu) if you have further questions regarding the use of the BTC at CTIO.

Note: Anyone interested in obtaining their own filters is recommended to have them made in the 5.75 x 5.75 inch size rather than 6 x 6 inches, with maximum thickness 12 mm. The smaller size will allow the filters to be useable both with the "NOAO Mosaic Imager" and with the BTC.