VIMOS grisms
The following tables describes the main characteristics of the grism offered in VIMOS.Each quadrant is equipped with is own set of grisms which performance are close. All grisms operate in first order and the transmission curve are available from the following table.
IMPORTANT NOTE A new set of four holographic HR_red grisms has been installed in VIMOS on October 5 2005. Compared to the previous set, the efficiency has increased of about 50%. We remind that before that date, there was no HR_red grism in quadrant 4. The grismHR_orange was instead automatically inserted in quadrant 4 when requesting the grism HR_red.The efficiency curve of the old HR Red grism is here.
| Name | Zero Deviation Wavelength (nm) | Wavelength coverage (nm) on detector with order sorting filter | Number of covered pixels | Resolution for 1" slit (MOS) - 1 fiber (IFU) | Dispersion (Angstrom/pixel) | Order sorting filter | Spectral multiplex MOS-IFU |
| LR-Red | 750 | 550-950 | 640 | 210-260 | 7.3 | OS-Red | 4 |
| LR-Blue | 480 | 360-670 | 640 | 180-220 | 5.3 | OS-blue | 4 |
| MR | 700 | 500-1000 | 2000 | 580-720 | 2.5 | GG475 | 1 |
| HR_Red | 740 | 630-870(1) | 4096 | 2500-3100 | 0.6 | GG475 | 1 |
| HR_orange | 631 | 520-760(1) | 4096 | 2150-2650 | 0.6 | GG435 | 1 |
| HR_blue | 510 | 415-620(1) | 4096 | 2050-2550 | 0.51 | Free | 1 |
(1) With slits at the center of the field of view. For more details see the following link.
The plots presenting the lines used for the wavelength calibrations of both the MOS and IFU can be found in the tool page.