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UKT14 facts

UKT14 Fact Sheet

Table 1 (below) gives the half power beamwidths for 65-mm apertures (HPBW_65) and for diffraction limited beams (HPBW_dl), flux conversion factors (G) and noise equivalent flux densities (NEFD) for the filters presently in use. Flux conversion factors and NEFD's are based on a 65mm aperture.

Filt/Apt	HPBW_65	HPBW_dl	G	NEFD	$\tau_{filter}$ / $\tau_{CSO}$
( $\mu$ m,mm)	(arcsec)	(arcsec)	(Jy/mV)	(Jy/ $\sqrt{Hz}$ )
2000/65	27.0	27.0	38 $\pm$ 1.5	-	0.90 $\pm$ 0.15
1300/65	19.1	19.1	13.8 $\pm$ 0.7	0.1-0.5	1.40 $\pm$ 0.06
1100/65	18.7	18.7	11.9 $\pm$ 0.5	0.4	1.90 $\pm$ 0.27
850/65	17.2	-	15.7 $\pm$ 0.9	-	3.2 $\pm$ 0.6
850/47	-	13.2	-	-	-
800/65	16.0	-	-see note-	0.4	-see note-
800/47	-	13.3	-	-	-
750/65	18.9	-	22 $\pm$ 3	-	7 $\pm$ 2
750/42	-	13.3	-	-	-
450/65	17.5	-	17 $\pm$ 2	>5	19.3 $\pm$ 1.9
450/27	-	8.3	-	-	-
350/65	19.0	-	27 $\pm$ 5	>10	22.6 $\pm$ 1.6
350/21	-	6.0	-	-	-

Notes:

Between $\tau_{800}$ 0.2 and 0.8 the flux conversion factor for the 800 $\mu$ m filter is G $_{800} = 5.1 + 7.3 \times \tau_{800}$ to within 10%.
The extinction at 800 $\mu$ m can be obtained from $\tau_{800}$ = 2.94( $\tau_{CSO}$ )^0.58 up to $\tau_{CSO}$ = 0.14 within 10%.
The tau meter at CSO presently does not give reliable tau values.
The most recent beam maps for UKT14 and filter profiles in ASCII format can be retrieved through anonymous FTP to JACH. Once logged in, change the directory to pub/jcmt/beams/latest to obtain the latest beam maps, or change to pub/jcmt/beams/filters to obtain the filter profiles.

Table 2: Beam map data for diffraction limited apertures

Filt/Apt	Date	Chop	Beam size	Power in error
( $\mu$ m, mm)		(arcsec)	X,Y (arcsec)	beam (%)
350/22	-	-	-	-
450/27 (M)	12/14/94	20	10.0 x 9.7	$\sim$ 40
750/42 (M)	05/15/94	40	14.2 x 13.1	-
800/47 (M)	12/11/94	40	14.1 x 13.9	$\sim$ 8
850/47 (U)	10/07/94	40	15.8 x 14.5	-
1100/65(M)	10/11/94	40	19.4 x 18.4	negligible
1300/65(M)	10/11/94	40	20.7 x 19.9	negligible
2000/65(U)	04/08/94	60	27.2 x 26.8	negligible

Fred Baas, July 15, 1999