MOSAIC Filters
The Mosaic II imager, used at the Blanco 4-m prime focus, takes filters that are 146x146 mm and 12 mm (nominal) thick. A set of standardized filter names and IDs for both Mosaic I on the KPNO Mayall and Mosaic II on the CTIO Blanco have been developed to ensure proper application of astrometric solutions and real-time display processing (as well as future archive uniformity). These official names are listed in the Mosaic filter list web page.
Focus offsets are referred to the R filter, since this is the filter we use for taking focus frames each night when the Mosaic is installed in order to monitor telescope performance.
Note that the Sloan set (griz) and the Johnson-Cousins BVR (but not I) sets should be near-identical to those at KPNO.
Note: The central wavelength of narrow band filters (actually all filters, but it is very significant for narrow band filters) is shifted approx. 15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelengths quoated below are nominally for when the filters used at PF, with the approx. 15A shift included. Furthermore, the filter transmission curves presented below show the simulated filter tranmission curve for the Blanco 4m + PFADC f/2.87 beam.
Note: The Blanco prime focus corrector has poor response in the UV: 90% (4000A), 85% (3800A), 74% (3650A), 54% (3500A), 31% (3400A), 11% (3350A), 0% (3300A). These are calculations from the glass types and AR coating specifications, and the figures for 3300-3400A are rather uncertain. YOU STRONGLY ENCOURAGED TO USE THE u(SDSS) filter rather than the U filter. Neither of these filters, in combination with the CCDs and optical corrector, match the standard passbands perfectly. The U filter uses a (troublesome!) copper sulphate solution as red blocker, whereas the SDSS u filter is an interference filter.
Mosaic
| Filter | FWHM (Å) | CWL (Å) | Telescope | Instrument | Plot | Data | Comments |
|---|---|---|---|---|---|---|---|
| D51 DDO 51 k1008 | Nicholas U. Mayall 4-meter Telescope | Mosaic | D51 DDO 51 k1008 | D51 DDO 51 k1008 | Below is a plot of this filter as simulated in different f/ratio beams.At the KPNO 4m f/3.1 the properties of this filter are: CWL=5132A FWHM=161A PEAK TRANSMISSION=85.1% | ||
| 815 815_v1 k1026 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 815 815_v1 k1026 | 815 815_v1 k1026 | |||
| 823 823_v2 k1047 | 68.02 | 8238.79 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 823 823_v2 k1047 | 823 823_v2 k1047 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page. Note: This is a replacement of the old Rhoads 823 filter (k1027) was purchased. See below for a comparison of the two filters. |
| 973 BATC k1065 ** | Nicholas U. Mayall 4-meter Telescope | Mosaic | 973 BATC k1065 ** | 973 BATC k1065 ** | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. | ||
| O3 OIII N2 k1014 * | 55.55 | 5024.90 | Nicholas U. Mayall 4-meter Telescope | Mosaic | O3 OIII N2 k1014 * | O3 OIII N2 k1014 * | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page. |
| 918R 918R_v1 k1028 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 918R 918R_v1 k1028 | ||||
| 454 BATC k1054 ** | Nicholas U. Mayall 4-meter Telescope | Mosaic | 454 BATC k1054 ** | 454 BATC k1054 ** | |||
| ha8 H-alpha+8nm c6011 | 80.00 | 6650.00 | Nicholas U. Mayall 4-meter Telescope | Mosaic | ha8 H-alpha+8nm c6011 | ha8 H-alpha+8nm c6011 | Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam. |
| R Harris k1004 | Nicholas U. Mayall 4-meter Telescope | Mosaic | R Harris k1004 | R Harris k1004 | |||
| wr475 WR 475 k1022 | 51.27 | 4764.00 | Nicholas U. Mayall 4-meter Telescope | Mosaic | wr475 WR 475 k1022 | wr475 WR 475 k1022 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page. |
| Rs Steidel k1043 | 1048.78 | 6975.13 | Nicholas U. Mayall 4-meter Telescope | Mosaic | Rs Steidel k1043 | Rs Steidel k1043 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. |
| 705 BATC k1060 ** | Nicholas U. Mayall 4-meter Telescope | Mosaic | 705 BATC k1060 ** | 705 BATC k1060 ** | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. | ||
| It Tyson I c6025 *** Not Available | 2000.00 | 8800.00 | Nicholas U. Mayall 4-meter Telescope | Mosaic | It Tyson I c6025 *** Not Available | It Tyson I c6025 *** Not Available | Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam. |
| ha H-alpha k1009 | 80.62 | 6574.74 | Nicholas U. Mayall 4-meter Telescope | Mosaic | ha H-alpha k1009 | ha H-alpha k1009 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page. |
| 815 815_v1 k1026 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 815 815_v1 k1026 | A comparison of this filter with the newer version of this filter (k1046): | |||
| 823 823_v2 k1047 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 823 823_v2 k1047 | 823 823_v2 k1047 | |||
| 973 BATC k1065 ** | Nicholas U. Mayall 4-meter Telescope | Mosaic | 973 BATC k1065 ** | 973 BATC k1065 ** | |||
| U k1001 | 630.71 | 3552.00 | Nicholas U. Mayall 4-meter Telescope | Mosaic | U k1001 | U k1001 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. |
| O3 OIII N2 k1014 * | Nicholas U. Mayall 4-meter Telescope | Mosaic | O3 OIII N2 k1014 * | O3 OIII N2 k1014 * | Below is a plot of the transmission of this filter when used at telescopes with differing focal ratios and central obscurations; the KPNO 4m (f/3.1), the CTIO 4m (f/2.9), and the WIYN 0.9m (f/7.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=5006A, FWHM=56A, PEAK TRANSMISSION=76%. | ||
| 918R 918R_v1 k1028 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 918R 918R_v1 k1028 | 918R 918R_v1 k1028 | Below is a plot of the transmission of this filter when used at telescopes with differing focal ratios and central obscurations; the KPNO 4m (f/3.1) and the CTIO 4m (f/2.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=9140A, FWHM=81A, PEAK TRANSMISSION=84.7%. | ||
| 493 BATC k1055 ** | Nicholas U. Mayall 4-meter Telescope | Mosaic | 493 BATC k1055 ** | 493 BATC k1055 ** | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. | ||
| o2 OII c6012 | 50.00 | 3727.00 | Nicholas U. Mayall 4-meter Telescope | Mosaic | o2 OII c6012 | o2 OII c6012 | Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam. |
| R Harris k1004 | Nicholas U. Mayall 4-meter Telescope | Mosaic | R Harris k1004 | ||||
| wr475 WR 475 k1022 | Nicholas U. Mayall 4-meter Telescope | Mosaic | wr475 WR 475 k1022 | wr475 WR 475 k1022 | Below is a plot of this filter as simulated in different f/ratio beams. At the KPNO 4m f/3.1 the properties of this filter are: CWL=4749A FWHM=51.32A PEAK TRANSMISSION=79.2%. | ||
| Rs Steidel k1043 | Nicholas U. Mayall 4-meter Telescope | Mosaic | Rs Steidel k1043 | Rs Steidel k1043 | |||
| 705 BATC k1060 ** | Nicholas U. Mayall 4-meter Telescope | Mosaic | 705 BATC k1060 ** | 705 BATC k1060 ** | |||
| ha H-alpha k1009 | Nicholas U. Mayall 4-meter Telescope | Mosaic | ha H-alpha k1009 | ha H-alpha k1009 | Below is a plot of the transmission of this filter when used at telescopes with differing focal ratios and central obscurations; the KPNO 4m (f/3.1), the CTIO 4m (f/2.9), and the WIYN 0.9m (f/7.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=6550A, FWHM=80A, PEAK TRANSMISSION=93.7%. | ||
| 815 815_v1 k1026 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 815 815_v1 k1026 | ||||
| 823 823_v2 k1047 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 823 823_v2 k1047 | A comparison of this filter with the newer version (k1047): | |||
| U c6001 | 650.00 | 3570.00 | Nicholas U. Mayall 4-meter Telescope | Mosaic | U c6001 | U c6001 | Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam. |
| U k1001 | Nicholas U. Mayall 4-meter Telescope | Mosaic | U k1001 | U k1001 | |||
| Ooff OIII+30nm k1015 | 242.69 | 5317.54 | Nicholas U. Mayall 4-meter Telescope | Mosaic | Ooff OIII+30nm k1015 | Ooff OIII+30nm k1015 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms redder. See the plot at the bottom of the page. |
| gd DECam k1035 *** New! | 1524.00 | 4744.90 | Nicholas U. Mayall 4-meter Telescope | Mosaic | gd DECam k1035 *** New! | gd DECam k1035 *** New! | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. |
| 493 BATC k1055 ** | Nicholas U. Mayall 4-meter Telescope | Mosaic | 493 BATC k1055 ** | 493 BATC k1055 ** | |||
| s2 SII c6013 | 80.00 | 6725.00 | Nicholas U. Mayall 4-meter Telescope | Mosaic | s2 SII c6013 | s2 SII c6013 | Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam. |
| I Nearly-Mould k1005 | 1914.59 | 8204.53 | Nicholas U. Mayall 4-meter Telescope | Mosaic | I Nearly-Mould k1005 | I Nearly-Mould k1005 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. |
| wrhe2 WR HeII k1023 | 50.31 | 4702.60 | Nicholas U. Mayall 4-meter Telescope | Mosaic | wrhe2 WR HeII k1023 | wrhe2 WR HeII k1023 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page. |
| Us solid U k1044 | 588.20 | 3651.81 | Nicholas U. Mayall 4-meter Telescope | Mosaic | Us solid U k1044 | Us solid U k1044 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. |
| 755 BATC k1061 ** | Nicholas U. Mayall 4-meter Telescope | Mosaic | 755 BATC k1061 ** | 755 BATC k1061 ** | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. | ||
| ha4 H-alpha+4nm k1010 | 80.48 | 6620.52 | Nicholas U. Mayall 4-meter Telescope | Mosaic | ha4 H-alpha+4nm k1010 | ha4 H-alpha+4nm k1010 | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. See the plot at the bottom of the page. |
| 815 815_v1 k1026 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 815 815_v1 k1026 | 815 815_v1 k1026 | Below is a plot of the transmission of this filter when used at telescopes with differing focal ratios and central obscurations; the KPNO 4m (f/3.1) and the CTIO 4m (f/2.9). At the KPNO 4m f/3.1 the properties of this filter are: CWL=8087A, FWHM=71A, PEAK TRANSMISSION=93%. | ||
| 823 823_v2 k1047 | Nicholas U. Mayall 4-meter Telescope | Mosaic | 823 823_v2 k1047 | 823 823_v2 k1047 | Below is a plot of this filter as simulated in different f/ratio beams. At the KPNO 4m f/3.1 the properties of this filter are: CWL= 8193.49A FWHM= 68.30A PEAK TRANSMISSION= 89.71% at 8182A | ||
| B Harris c6002 | 990.00 | 4360.00 | Nicholas U. Mayall 4-meter Telescope | Mosaic | B Harris c6002 | B Harris c6002 | Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam. |
| U k1001 | Nicholas U. Mayall 4-meter Telescope | Mosaic | U k1001 | ||||
| Ooff OIII+30nm k1015 | Nicholas U. Mayall 4-meter Telescope | Mosaic | Ooff OIII+30nm k1015 | Ooff OIII+30nm k1015 | Below is a plot of this filter as simulated in different f/ratio beams.At the KPNO 4m f/3.1 the properties of this filter are: CWL=5298.69A FWHM=240.20A PEAK TRANSMISSION=91.73% | ||
| rd DECam k1036 *** New! | 1426.90 | 6395.60 | Nicholas U. Mayall 4-meter Telescope | Mosaic | rd DECam k1036 *** New! | rd DECam k1036 *** New! | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. |
| 527 BATC k1056 ** | Nicholas U. Mayall 4-meter Telescope | Mosaic | 527 BATC k1056 ** | 527 BATC k1056 ** | Note that there is a shift in central wavelength when placed in different f/ratio beams. At the KPNO 4meter f/3.1 beam this corresponds to a shift of approximately 12 Angstroms bluer; at the CTIO 4meter f/2.9 this corresponds to a shift of approximately 15 Angstroms bluer; at the WIYN 0.9m f/7.9 this corresponds to a shift of approximately 5 Angstroms bluer. | ||
| o3 OIII c6014 | 50.00 | 4990.00 | Nicholas U. Mayall 4-meter Telescope | Mosaic | o3 OIII c6014 | o3 OIII c6014 | Note: The central wavelength of CTIO Mosaic narrow band filters (actually all filters, but is very significant for narrow band filters) is shifted ~15A to the BLUE in the f/2.87 beam of the Blanco 4m + PFADC corrector as compared to the transmission measured in parallel light. The central wavelength quoted below is nominally for when the filter is used at PF, with the ~15A shift included. Furthermore, the filter transmission curve presented below shows the simulated filter transmission curve for the Blanco 4m + PFADC f/2.87 beam. |
| I Nearly-Mould k1005 | Nicholas U. Mayall 4-meter Telescope | Mosaic | I Nearly-Mould k1005 | I Nearly-Mould k1005 | |||
| wrhe2 WR HeII k1023 | Nicholas U. Mayall 4-meter Telescope | Mosaic | wrhe2 WR HeII k1023 | wrhe2 WR HeII k1023 | Below is a plot of this filter as simulated in different f/ratio beams. At the KPNO 4m the properties of this filter are: CWL=4695A FWHM=51.34A PEAK TRANSMISSION=74.83%. |
Last updated: 2009 Dec 9, ARW
Staff Contacts:
Sean Points: spointsATctio.noao.edu
Alistair Walker: awalkerATctio.noao.edu
Updated on June 5, 2021, 8:00 pm