The DEIMOS slitmask cassette has room for 11 masks, but since
one slot is typically reserved for the focusing mask, only 10
are typically available for observer use. In addition to
custom-designed user masks, the observatory maintains a set of
standard masks for longslit observations and instrument
focusing, as described below.
| Mask Name |
Description |
DesID |
Barcode |
Status |
| Longslit Masks |
| LVMslitC |
Multiple slitlets (0.7, 0.8, 1.0, 1.2,
1.5 arcsec widths; all 20 arcsec long) on reflective
mask. From left to right as seen on the guider are slits
of width 1.5, 1.2, 1.0, 0.8, and 0.7. Identical to mask
LVMslitB except that slits are shift by 10 arcsec
toward the mask center in spatial direction to avoid
bad columns. See notes on manufacturing
this mask. |
11725 |
10260 |
damaged, retired March 2017 |
| 9400 |
no shoulders, retired 2017-08-10 |
| 10810 |
damaged, retired 2017-08-17 |
| 10830 |
damaged, retired 2020-11-09 |
| 10840 |
active |
| LongMirr |
0.7 arcsec wide × 205 arcsec long single slit on
reflective mask |
1684 |
11352 |
active |
| 11353 |
spare |
| 1218 |
damaged,retired |
| Long0.7 |
0.7 arcsec wide longslit, consisting of
12 separate slitlets, each 82 arcsec long, with a small
gap or "bridge" in between in order to prevent the slit
from buckling. |
523 |
4948 |
damaged, retired |
| 7357 |
damaged, retired |
| 9120 |
damaged, retired |
| 9645 |
active |
| 9800 |
spare |
| Long0.8 |
0.8 arcsec longslit, consisting of
12 separate slitlets, each 82 arcsec long, with a small
gap or "bridge" in between in order to prevent the slit
from buckling. |
524 |
7441 |
active |
| 7371 |
spare |
| Long1.0B |
1.0 arcsec longslit, consisting of
12 separate slitlets, each 82 arcsec long, with a small
gap or "bridge" in between in order to prevent the slit
from buckling. |
525 |
7358 |
retired |
| 9090 |
retired |
| 10150 |
retired |
| 10141 |
active |
| 10140 |
spare |
| 10139 |
spare |
| Long1.2 |
1.2 arcsec longslit, consisting of
12 separate slitlets, each 82 arcsec long, with a small
gap or "bridge" in between in order to prevent the slit
from buckling. |
526 |
4311 |
retired |
| 1090 |
retired |
| 7359 |
active |
| Long1.5 |
1.5 arcsec longslit, consisting of
12 separate slitlets, each 82 arcsec long, with a small
gap or "bridge" in between in order to prevent the slit
from buckling. |
527 |
7069 |
retired |
| 11351 |
active |
| NONE |
spare |
| LVMslitB |
Multiple slitlets (0.7, 0.8, 1.0, 1.2,
1.5 arcsec widths; all 20 arcsec long) on reflective
mask. From left to right as seen on the guider are slits
of width 1.5, 1.2, 1.0, 0.8, and 0.7.
| |
7542 |
retired, superseded by LVMslitC |
| LongSlit |
1.0 arcsec longslit |
|
1982 |
retired |
| LongA |
1.0 arcsec longslit |
|
1891 |
scratched up, retired |
| Long1.0 |
1.0 arcsec longslit |
|
488 |
retired? |
| LngVrMir |
Multiple slitlets (0.7, 0.9, 1.1, 1.5 arcsec widths; all 20
arcsec long) on reflective mask
From left to right
as seen on the guider are slits of width
1.5, 1.1, 0.9, and 0.7. |
|
1556 |
retired |
| Focusing Masks |
| GOH_X (GOH_foo) |
Grid of pinholes through mask, imaging
focus mask.
This is the mask typically used for
focusing DEIMOS in the afternoon. |
448 |
487 |
retired |
| 2124 |
retired |
| 2125 |
retired |
| 10160 |
active |
| 10180 |
active |
|
spare |
| GOSpH |
Grid of spectral holes; spectroscopy focus mask.
This mask is used only for engineering purposes. |
6741 |
6205 |
retired |
| 6206 |
active |
| 6207 |
spare |
| GOH_TV |
Grid of holes not quite drilled through the mask,
intended for helping determine TV focus
|
|
1926 |
obsolete; retired |
| GOSpH3 |
Grid of spectral holes; spectroscopy focus mask |
|
1966 |
obsolete, retired |
| GOH_X |
Grid of pinholes through mask, imaging focus mask |
|
1927 |
damaged, retired |
| GOH_foo |
Grid of pinholes through mask, imaging focus mask |
|
486 |
damaged, retired |
| GOSpH |
Grid of spectral holes; spectroscopy focus mask |
|
1930 |
retired |
| GOSpH2 |
Grid of spectral holes; spectroscopy focus mask |
|
1977 |
retired |
See Also
|
