Facility Slitmask Inventory

The following standard slitmasks are available for use with LRIS.

Slitmask Name Comments
Standard Longslits
long_0.7 Longslit 0.7 arcsec wide × 175 arcsec long
long_1.0 Longslit 1.0 arcsec wide × 175 arcsec long
long_1.5 Longslit 1.5 arcsec wide × 175 arcsec long
long_8.7 Longslit 8.7 arcsec wide × 175 arcsec long
Polarimetry Longslits
pol_1.0 Longslit 1.0 arcsec wide × 25 arcsec long
pol_1.5 Longslit 1.5 arcsec wide × 25 arcsec long
Imaging Focus Masks
focus_holes 17 columns × 22 rows of small holes, 13.3 mm apart

Multi Object Slitmasks

Multiobject Slitmasks are used by observers who desire to acquire more than one spectrum at a time. Prior to your run, slits are milled into sheets of aluminum by summit staff to prepair your slitmasks as specified in design files submitted to the slitmask database (see table below). The masks are then inserted into LRIS during the afternoon of your observing session. In practice, there are eight free slots available for user slitmasks. There are ten positions available, but two are reserved for "direct" imaging and a grid of "focus holes" used to focus the instrument in the afternoon.

Designing new slitmasks?

Please review the different slitmask procedures and the design tips page at the bottom of the table. Most observers use the Autoslit3 software to design their masks.

Mask-Design-Files (MDFs) are currently submitted via a Web Form (LRIS/DEIMOS Slitmask submission database ). Masks will be milled automatically after they are successfully ingested in the database. Please follow the Slitmask Design Submission Procedure to submit a mask for milling.

Below is a table of information that you may find useful in regards to slitmasks.

Mask Alignment Procedures

Slitmask alignment WITH pick-off mirrors
Slitmask alignment WITHOUT pick-off mirrors

Mask design software
  (Autoslit3 - Caltech)

Mask design with Autoslit3
Autoslit3 manual
Download Autoslit3: ftp site at Caltech

Mask design software

UCSCLRIS an alternative mask design software

Object Coordinates from LRIS images

Measure coordinates from LRIS images
Download the coordinates source code

Slitmask Submissions

Slitmask Design Submission Procedure: Follow these steps to submit a mask design file.
Masks submission and fabrication: connect to the mask database at Lick.
Slitmask Status:: Allows you to monitor the slitmask inventory listed in chronological order.
Design Tips and Considerations