Table 1.1.3

FOS Line Widths (FWHM) as a Function of Aperture Size

Designation

0.3

0.5

1.0

0.1-PAIR

0.25-PAIR

0.5-PAIR

1.0-PAIR

0.25 X 2.0

0.7 X 2.0-BAR

2.0-BAR

4.3

Size ()

0.26 (circular)

0.43(circular)

0.86(circular)

0.09(square)

0.21(square)

0.43(square)

0.86(square)

0.21 X 1.71(slit)

0.60 X 1.71

1.71

3.66 X 3.71

Aperture Filled with 

Uniform Source

G130H (Blue)

FWHM

1.00+_ .01

1.27+_ .04

2.29+_ .02

0.97+_ .03

0.98+_ .01

1.30+_ .04

2.65+_ .02

0.99+_ .01

1.83+_ .02

5.28+_ .07

12.2 +_ 0.1

G570H (Red)

FWHM

0.95+_ .02

1.20+_ .01

2.23+_ .01

0.92+_ .02

0.96+_ .01

1.34+_ .02

2.71+_ .02

0.96+_ .01

1.90+_ .01

5.43+_ .04

12.2 +_ 0.1

Point Source

at 3400Å

FWHM

0.92

0.93

0.96

0.91

0.92

0.94

0.96

0.92

1.26

1.34

0.96

The FWHM are given in units of diodes. A diode is 0.30 wide and 1.21 high.