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SCUBA FCFs
SCUBA Flux Conversion Factors |
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We strongly recommend you calculate Flux Conversion Factors (FCFs) from calibration measurements taken on the same night as your science observations. The values below should only be used as guidelines to SCUBA's typical performance in a given time period. The notes below give more details about these values and their derivation.
850-µm data
| Dates |
Photometry FCF |
Jigglemap FCFs |
| |
Jy/volt |
Per beam: Jy/beam/volt |
Per aperture:
Jy/square arcsec/volt |
| 1st Sept 99 - 30th June 00 |
197 ± 13 |
219 |
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| 1st July 00 - 15th May 01 |
200 ± 13 |
216 |
0.88 |
| 16th May 01 - 1st June 01 |
206 ± 12 |
280 |
1.13 |
| 2nd June 01 - 4th Feb 02 |
209 ± 11 |
0.86 ± 0.05 |
| 5th Feb 02 - 30th June 02 |
224 ± 16 |
0.88 ± 0.04 |
| 1st July 02 - 1st Dec 02 |
239 ± 32 |
278 ± 36 |
1.09 ± 0.15 |
| 2nd Dec 02 - 31st Dec 02 |
194 ± 14 |
0.79 ± 0.05 |
| 1st Jan 03 - 31st Jan 03 |
194 ± 7 |
193 ± 9 |
0.80 ± 0.05 |
| 1st Feb 03 - 9th Feb 03 |
204 ± 14 |
0.89 ± 0.02 |
| 10th Feb 03 - 28th Feb 03 |
233 ± 16 |
255 ± 1 |
1.02 ± 0.02 |
| 1st Mar 03 - 7th Apr 03 |
230 ± 14 |
0.98 ± 0.05 |
| 8th Apr 03 - 17th May 03 |
213 ± 24 |
0.83 ± 0.07 |
| 18th May 03 - 30th June 03 |
202 ± 13 |
212 ± 11 |
0.87 ± 0.04 |
| 1st July 03 - 26th July 03 |
206 ± 6 |
0.83 ± 0.02 |
| 27th July 03 - 22nd Aug 03 |
218 ± 15 |
0.86 ± 0.08 |
| 23rd Aug 03 - 16th Sept 03 |
196 ± 6 |
0.79 ± 0.02 |
| 17th Sept 03 - 19th Oct 03 |
201 ± 16 |
0.78 ± 0.05 |
| 20th Oct 03 - 31st Dec 03 |
216 ± 16 |
0.83 ± 0.05 |
| 1st Jan 04 - 12th Feb 04 |
218 ± 12 |
0.84 ± 0.03 |
| 13th Feb 04 - 4th Apr 04 |
221 ± 6 |
231 ± 14 |
0.85 ± 0.05 |
450-µm data
| Dates |
Photometry FCF |
Jigglemap FCFs |
| |
Jy/volt |
Per beam: Jy/beam/volt |
Per aperture:
Jy/square arcsec/volt |
| 1st Jan 00 - 31st Mar 00 |
384 ± 80 |
310 |
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| 1st Apr 00 - 31st Dec 00 |
361 ± 85 |
340 |
3.2 |
| 1st Jan 01 - 4th Feb 02 |
295 ± 65 |
260 ± 100 |
2.78 ± 0.8 |
| 5th Feb 02 - 30th June 02 |
377 ± 185 |
| 1st Jul 02 - 1st Dec 02 |
409 ± 180 |
500 ± 200 |
4.13 ± 1.0 |
| 2nd Dec 02 - 9th Feb 03 |
260 ± 60 |
2.45 ± 1.0 |
| 10th Feb 03 - 28th Feb 03 |
320 ± 80 |
400 ± 90 |
3.3 ± 0.6 |
| 1st Mar 03 - 7th Apr 03 |
330 ± 100 |
2.85 ± 1.2 |
| 8th Apr 03 - 17th May 03 |
270 ± 30 |
2.24 ± 0.4 |
| 18th May 03 - 30th June 03 |
380 ± 70 |
302 ± 30 |
2.76 ± 0.2 |
| 1st July 03 - 26th July 03 |
284 ± 20 |
2.61 ± 0.2 |
| 27th July 03 - 22nd Aug 03 |
245 ± 40 |
2.33 ± 0.3 |
| 23rd Aug 03 - 19th Oct 03 |
316 ± 70 |
2.72 ± 0.6 |
| 20th Oct 03 - 31st Dec 03 |
379 ± 55 |
3.2 ± 0.4 |
| 1st Jan 04 - 12th Feb 04 |
414 ± 115 |
3.1 ± 0.3 |
| 13th Feb 04 - 4th Apr 04 |
480 ± 60 |
528 ± 200 |
3.6 ± 0.8 |
Notes :
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The time periods shown above are suggested by patterns in the FCF data; breaks tend to correspond to known events such as the summer warm-up and engineering in 2002, or to known behaviour problems with SCUBA. Photometry data at both wavelengths, and 450-µm data generally have fewer obvious changes of behaviour because there are fewer data. Long time periods may mean SCUBA was stable, or it may mean there weren't many data taken!
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The FCF behaviour will now be reviewed approximately monthly, using the CSO-tau fits for each night.
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Jiggle-map FCFs are given in two forms: per beam, which is suitable only for use with unresolved point sources and calibrators, and per aperture, which is suitable for use with extended sources. The aperture used here is a 40" circle. See Jenness et al. 2002, MNRAS, 336, 14-21 for more information on this.
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Data for the other wavelength bolometers on the JCMT, which have not been in operation for some years now, are still available on request.
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