F25QTZD1 - FUV-MAMA, Longpass Pseudo-Aperture


The F25QTZD1 filter is intended to be used with the G140L and G140M gratings for spectroscopic observations of very faint targets at the D1 position that require better rejection of geocoronal emission than provided by F25MAMAD1 or F25SRF2D1.  It is the same optical element as the F25QTZ filter.  This aperture moves the target 2 arcseconds above the bottom edge of the FUV-MAMA.  It is yet to be determined if the throughput for a target at this position is significantly different from that obtained at the standard position.

Special Considerations

Refer to Section F25QTZ—FUV-MAMA for information concerning the properties of the F25QTZD1 filter.  Note that it can only be used with the G140L and G140M gratings.