STIS Instrument Handbook for Cycle 24

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Echelle Line Spread Functions

Table 13.43: Spectral Resolution for Echelle Medium-Resolution Modes (E230M, E140M)

Slit	Spectral Resolution (FWHM in pixels)
	Point Source					Extended Source
	1200 å	1500 å	1700 å1	1700 å2	2400 å
0.1X0.03	0.9	0.9	1.0	1.6	1.6	~1
0.2X0.2	1.4	1.3	1.1	2.0	1.9	~6
0.2X0.06	1.3	1.2	1.1	1.8	1.7	~2
6X0.2	1.6	1.4	1.2	2	1.9	~6

1

FWHM with FUV-MAMA (E140M).

2

FWHM with NUV-MAMA (E230M).

Figure 13.92: Echelle Line Spread Functions, E140M (top) and E230M (bottom)

Table 13.44: Spectral Resolution for Echelle High Resolution Modes (E140H, E230H)

Slit	Spectral Resolution (FWHM in pixels)
	Point Source					Extended Source
	1200 å	1500 å	1700 å1	1700 å2	2400 å
0.1X0.03	0.8	0.8	1	1.5	1.5	~1
0.2X0.2	1.3	1.1	1	1.8	1.7	~6
0.2X0.09	1.2	1.1	1	1.7	1.7	~2
6X0.2	1.4	1.2	1.2	2	1.8	~5

1

FWHM with FUV-MAMA (E140H).

2

FWHM with NUV-MAMA (E230H).

Figure 13.93: Echelle Line Spread Functions, E140H (top) and E230H (bottom). LSFs for E230H were derived using the 0.1X0.2 and 0.1X0.09 apertures; results for 0.2X0.2 and 0.2X0.09 should be similar.